cytoBand Chromosome Band Chromosome Bands Mapping and Sequencing Description This track shows D. melanogaster cytogenetic locations, mapped to the release 3 genome sequence by Aubrey de Grey of FlyBase, July 2002. Credits We would like to thank FlyBase and Aubrey de Grey for providing this information. 
cytoBandIdeo Chromosome Band (Low-res) Chromosome Bands (Low-resolution for Chromosome Ideogram) Mapping and Sequencing 
refGene RefSeq Genes RefSeq Genes Genes and Gene Predictions Description The RefSeq Genes track shows known D. melanogaster protein-coding and non-protein-coding genes taken from the NCBI RNA reference sequences collection (RefSeq). The data underlying this track are updated weekly. Please visit the Feedback for Gene and Reference Sequences (RefSeq) page to make suggestions, submit additions and corrections, or ask for help concerning RefSeq records. Display Conventions and Configuration This track follows the display conventions for gene prediction tracks. The color shading indicates the level of review the RefSeq record has undergone: predicted (light), provisional (medium), reviewed (dark). The item labels and display colors of features within this track can be configured through the controls at the top of the track description page. This page is accessed via the small button to the left of the track's graphical display or through the link on the track's control menu. Label: By default, items are labeled by gene name. Click the appropriate Label option to display the accession name instead of the gene name, show both the gene and accession names, or turn off the label completely. Codon coloring: This track contains an optional codon coloring feature that allows users to quickly validate and compare gene predictions. To display codon colors, select the genomic codons option from the Color track by codons pull-down menu. Click here for more information about this feature. Hide non-coding genes: By default, both the protein-coding and non-protein-coding genes are displayed. If you wish to see only the coding genes, click this box. Methods RefSeq RNAs were aligned against the D. melanogaster genome using blat; those with an alignment of less than 15% were discarded. When a single RNA aligned in multiple places, the alignment having the highest base identity was identified. Only alignments having a base identity level within 0.1% of the best and at least 96% base identity with the genomic sequence were kept. Credits This track was produced at UCSC from RNA sequence data generated by scientists worldwide and curated by the NCBI RefSeq project. References Kent WJ. BLAT--the BLAST-like alignment tool. Genome Res. 2002 Apr;12(4):656-64. PMID: 11932250; PMC: PMC187518 Pruitt KD, Tatusova T, Maglott DR. NCBI Reference Sequence (RefSeq): a curated non-redundant sequence database of genomes, transcripts and proteins. Nucleic Acids Res. 2005 Jan 1;33(Database issue):D501-4. PMID: 15608248; PMC: PMC539979 
pscreen BDGP Insertions BDGP Gene Disruption Project P-element Insertion Locations Mapping and Sequencing Description This track shows the locations of P transposable element insertions from P-Screen, the online database of the BDGP Gene Disruption Project. Triangular arrows indicate the approximate positions in the reference sequence at which P elements have been inserted. The direction of the arrow corresponds to the orientation of the insertion: right-pointing arrows indicate forward orientation; left-pointing arrows show reverse orientation. The item name indicates the strain that has a P element disruption at that location. When a stock order number is available for the strain, a link is provided to the Bloomington stock center where the strain can be ordered. The project's strain library contains more than 7140 strains disrupting at least 5362 different genes, corresponding to 39% of the 13,666 currently annotated Drosophila genes. Methods See the P-Screen homepage for materials and methods. See also a list of publications on the Gene Disruption Project. Credits Thanks to the BDGP Gene Disruption Project for providing these data. Please cite the Bellen et al. reference below when using strains from the collection. References Bellen HJ, Levis RW, Liao G, He Y, Carlson JW, Tsang G, Evans-Holm M, Hiesinger PR, Schulze KL, Rubin GM et al. The BDGP gene disruption project: single transposon insertions associated with 40% of Drosophila genes. Genetics. 2004 Jun;167(2):761-81. PMID: 15238527; PMC: PMC1470905 
bdgpGene FlyBase Genes Protein-Coding Genes from FlyBase Genes and Gene Predictions Description This track shows protein-coding genes annotated by FlyBase (version 3.2). Credits Thanks to FlyBase for providing these annotations. 
bdgpNonCoding FlyBase Non-coding Non-Coding Genes from FlyBase Genes and Gene Predictions Description This track shows non-coding genes annotated by FlyBase (version 3.2). Credits Thanks to FlyBase for providing these annotations. 
intronEst Spliced ESTs D. melanogaster ESTs That Have Been Spliced mRNA and EST Description This track shows alignments between D. melanogaster expressed sequence tags (ESTs) in GenBank and the genome that show signs of splicing when aligned against the genome. ESTs are single-read sequences, typically about 500 bases in length, that usually represent fragments of transcribed genes. To be considered spliced, an EST must show evidence of at least one canonical intron, i.e. one that is at least 32 bases in length and has GT/AG ends. By requiring splicing, the level of contamination in the EST databases is drastically reduced at the expense of eliminating many genuine 3' ESTs. For a display of all ESTs (including unspliced), see the D. melanogaster EST track. Display Conventions and Configuration This track follows the display conventions for PSL alignment tracks. In dense display mode, darker shading indicates a larger number of aligned ESTs. The strand information (+/-) indicates the direction of the match between the EST and the matching genomic sequence. It bears no relationship to the direction of transcription of the RNA with which it might be associated. The description page for this track has a filter that can be used to change the display mode, alter the color, and include/exclude a subset of items within the track. This may be helpful when many items are shown in the track display, especially when only some are relevant to the current task. To use the filter: Type a term in one or more of the text boxes to filter the EST display. For example, to apply the filter to all ESTs expressed in a specific organ, type the name of the organ in the tissue box. To view the list of valid terms for each text box, consult the table in the Table Browser that corresponds to the factor on which you wish to filter. For example, the "tissue" table contains all the types of tissues that can be entered into the tissue text box. Wildcards may also be used in the filter. If filtering on more than one value, choose the desired combination logic. If "and" is selected, only ESTs that match all filter criteria will be highlighted. If "or" is selected, ESTs that match any one of the filter criteria will be highlighted. Choose the color or display characteristic that should be used to highlight or include/exclude the filtered items. If "exclude" is chosen, the browser will not display ESTs that match the filter criteria. If "include" is selected, the browser will display only those ESTs that match the filter criteria. This track may also be configured to display base labeling, a feature that allows the user to display all bases in the aligning sequence or only those that differ from the genomic sequence. For more information about this option, click here. Methods To make an EST, RNA is isolated from cells and reverse transcribed into cDNA. Typically, the cDNA is cloned into a plasmid vector and a read is taken from the 5' and/or 3' primer. For most — but not all — ESTs, the reverse transcription is primed by an oligo-dT, which hybridizes with the poly-A tail of mature mRNA. The reverse transcriptase may or may not make it to the 5' end of the mRNA, which may or may not be degraded. In general, the 3' ESTs mark the end of transcription reasonably well, but the 5' ESTs may end at any point within the transcript. Some of the newer cap-selected libraries cover transcription start reasonably well. Before the cap-selection techniques emerged, some projects used random rather than poly-A priming in an attempt to retrieve sequence distant from the 3' end. These projects were successful at this, but as a side effect also deposited sequences from unprocessed mRNA and perhaps even genomic sequences into the EST databases. Even outside of the random-primed projects, there is a degree of non-mRNA contamination. Because of this, a single unspliced EST should be viewed with considerable skepticism. To generate this track, D. melanogaster ESTs from GenBank were aligned against the genome using blat. Note that the maximum intron length allowed by blat is 750,000 bases, which may eliminate some ESTs with very long introns that might otherwise align. When a single EST aligned in multiple places, the alignment having the highest base identity was identified. Only alignments having a base identity level within 0.5% of the best and at least 96% base identity with the genomic sequence are displayed in this track. Credits This track was produced at UCSC from EST sequence data submitted to the international public sequence databases by scientists worldwide. References Benson DA, Karsch-Mizrachi I, Lipman DJ, Ostell J, Wheeler DL. GenBank: update. Nucleic Acids Res. 2004 Jan 1;32(Database issue):D23-6. PMID: 14681350; PMC: PMC308779 Kent WJ. BLAT - the BLAST-like alignment tool. Genome Res. 2002 Apr;12(4):656-64. PMID: 11932250; PMC: PMC187518 
flyreg FlyReg FlyReg: Drosophila DNase I Footprint Database Expression and Regulation Description This track shows DNase I Footprint data from FlyReg version 1.0. FlyReg provides access to results of the systematic curation and genome annotation of 1,350 DNase I footprints for the fruitfly D. melanogaster reported in Bergman, C.M. et al. (see below). When available, a footprint motif is also displayed, based on a MEME matrix computed by Dan Pollard on the set of footprints for this factor. Credits Thanks to Casey Bergman for providing the FlyReg data. If used in published work, please cite Bergman CM, Carlson JW, Celniker SE. Drosophila DNase I footprint database: a systematic genome annotation of transcription factor binding sites in the fruitfly, Drosophila melanogaster. Bioinformatics. 2005 Apr 15;21(8):1747-9. PMID: 15572468 Thanks to Dan Pollard for providing the footprint motif matrices. 
augustusGene AUGUSTUS AUGUSTUS ab initio gene predictions v3.1 Genes and Gene Predictions Description This track shows ab initio predictions from the program AUGUSTUS (version 3.1). The predictions are based on the genome sequence alone. For more information on the different gene tracks, see our Genes FAQ. Methods Statistical signal models were built for splice sites, branch-point patterns, translation start sites, and the poly-A signal. Furthermore, models were built for the sequence content of protein-coding and non-coding regions as well as for the length distributions of different exon and intron types. Detailed descriptions of most of these different models can be found in Mario Stanke's dissertation. This track shows the most likely gene structure according to a Semi-Markov Conditional Random Field model. Alternative splicing transcripts were obtained with a sampling algorithm (--alternatives-from-sampling=true --sample=100 --minexonintronprob=0.2 --minmeanexonintronprob=0.5 --maxtracks=3 --temperature=2). The different models used by Augustus were trained on a number of different species-specific gene sets, which included 1000-2000 training gene structures. The --species option allows one to choose the species used for training the models. Different training species were used for the --species option when generating these predictions for different groups of assemblies. Assembly Group Training Species Fish zebrafish Birds chicken Human and all other vertebrates human Nematodes caenorhabditis Drosophila fly A. mellifera honeybee1 A. gambiae culex S. cerevisiae saccharomyces This table describes which training species was used for a particular group of assemblies. When available, the closest related training species was used. Credits Thanks to the Stanke lab for providing the AUGUSTUS program. The training for the chicken version was done by Stefanie König and the training for the human and zebrafish versions was done by Mario Stanke. References Stanke M, Diekhans M, Baertsch R, Haussler D. Using native and syntenically mapped cDNA alignments to improve de novo gene finding. Bioinformatics. 2008 Mar 1;24(5):637-44. PMID: 18218656 Stanke M, Waack S. Gene prediction with a hidden Markov model and a new intron submodel. Bioinformatics. 2003 Oct;19 Suppl 2:ii215-25. PMID: 14534192 
mzDy1Dp2Ag1_phast Conservation D.mel./D.yakuba/D.pseudo./A.gambiae Multiz Alignments & phastCons Scores Comparative Genomics Description This track shows a measure of evolutionary conservation in three Drosophila species and mosquito (A. gambiae), based on a phylogenetic hidden Markov model (phastCons). Multiz alignments of the following assemblies were used to generate this annotation: D. melanogaster Jan. 2003 (BDGP R3/dm1) (dm1) D. yakuba Apr. 2004 (droYak1) D. pseudoobscura Aug. 2003 (dp2) A. gambiae Sep. 2003 (anoGam1) In full display mode, this track shows the overall conservation score across all species as well as pairwise alignments of D. yakuba, D. pseudoobscura, and A. gambiae, each aligned to the D. melanogaster genome. The pairwise alignments are shown in dense display mode using a grayscale density gradient. The checkboxes in the track configuration section allow the exclusion of species from the pairwise display; however, this does not remove them from the conservation score display. When zoomed-in to the base-display level, the track shows the base composition of each alignment. The numbers and symbols on the Gaps line indicate the lengths of gaps in the D. melanogaster sequence at those alignment positions relative to the longest non-D. melanogaster sequence. If there is sufficient space in the display, the size of the gap is shown; if not, and if the gap size is a multiple of 3, a "*" is displayed, otherwise "+" is shown. To view detailed information about the alignments at a specific position, zoom in the display to 30,000 or fewer bases, then click on the alignment. This track may be configured in a variety of ways to highlight different aspects of the displayed information. Click the Graph configuration help link for an explanation of the configuration options. Methods Best-in-genome blastz pairwise alignments were multiply aligned using multiz, beginning with D. melanogaster-D. yakuba alignments and subsequently adding in D. pseudoobscura and A. gambiae. The resulting multiple alignments were then assigned conservation scores by phastCons. The phastCons program computes conservation scores based on a phylo-HMM, a type of probabilistic model that describes both the process of DNA substitution at each site in a genome and the way this process changes from one site to the next (Felsenstein and Churchill 1996, Yang 1995, Siepel and Haussler 2005). PhastCons uses a two-state phylo-HMM, with a state for conserved regions and a state for non-conserved regions. The value plotted at each site is the posterior probability that the corresponding alignment column was "generated" by the conserved state of the phylo-HMM. These scores reflect the phylogeny (including branch lengths) of the species in question, a continuous-time Markov model of the nucleotide substitution process, and a tendency for conservation levels to be autocorrelated along the genome (i.e., to be similar at adjacent sites). The general reversible (REV) substitution model was used. Note that, unlike many conservation-scoring programs, phastCons does not rely on a sliding window of fixed size, so short highly-conserved regions and long moderately conserved regions can both obtain high scores. More information about phastCons can be found in Siepel et al. (2005). PhastCons currently treats alignment gaps as missing data, which sometimes has the effect of producing undesirably high conservation scores in gappy regions of the alignment. We are looking at several possible ways of improving the handling of alignment gaps. Credits This track was created at UCSC using the following programs: Blastz and multiz by Minmei Hou, Scott Schwartz and Webb Miller of the Penn State Bioinformatics Group. AxtBest, axtChain, chainNet, netSyntenic, and netClass by Jim Kent at UCSC. PhastCons by Adam Siepel at Cornell University. "Wiggle track" plotting software by Hiram Clawson at UCSC. References Phylo-HMMs and phastCons: Felsenstein J, Churchill GA. A Hidden Markov Model approach to variation among sites in rate of evolution. Mol Biol Evol. 1996 Jan;13(1):93-104. PMID: 8583911 Siepel A, Bejerano G, Pedersen JS, Hinrichs AS, Hou M, Rosenbloom K, Clawson H, Spieth J, Hillier LW, Richards S, et al. Evolutionarily conserved elements in vertebrate, insect, worm, and yeast genomes. Genome Res. 2005 Aug;15(8):1034-50. PMID: 16024819; PMC: PMC1182216 Siepel A, Haussler D. Phylogenetic Hidden Markov Models. In: Nielsen R, editor. Statistical Methods in Molecular Evolution. New York: Springer; 2005. pp. 325-351. Yang Z. A space-time process model for the evolution of DNA sequences. Genetics. 1995 Feb;139(2):993-1005. PMID: 7713447; PMC: PMC1206396 Chain/Net: Kent WJ, Baertsch R, Hinrichs A, Miller W, Haussler D. Evolution's cauldron: duplication, deletion, and rearrangement in the mouse and human genomes. Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11484-9. PMID: 14500911; PMC: PMC208784 Multiz: Blanchette M, Kent WJ, Riemer C, Elnitski L, Smit AF, Roskin KM, Baertsch R, Rosenbloom K, Clawson H, Green ED, et al. Aligning multiple genomic sequences with the threaded blockset aligner. Genome Res. 2004 Apr;14(4):708-15. PMID: 15060014; PMC: PMC383317 Blastz: Chiaromonte F, Yap VB, Miller W. Scoring pairwise genomic sequence alignments. Pac Symp Biocomput. 2002:115-26. PMID: 11928468 Schwartz S, Kent WJ, Smit A, Zhang Z, Baertsch R, Hardison RC, Haussler D, Miller W. Human-mouse alignments with BLASTZ. Genome Res. 2003 Jan;13(1):103-7. PMID: 12529312; PMC: PMC430961 
est D. melanogaster ESTs D. melanogaster ESTs Including Unspliced mRNA and EST Description This track shows alignments between D. melanogaster expressed sequence tags (ESTs) in GenBank and the genome. ESTs are single-read sequences, typically about 500 bases in length, that usually represent fragments of transcribed genes. Display Conventions and Configuration This track follows the display conventions for PSL alignment tracks. In dense display mode, the items that are more darkly shaded indicate matches of better quality. The strand information (+/-) indicates the direction of the match between the EST and the matching genomic sequence. It bears no relationship to the direction of transcription of the RNA with which it might be associated. The description page for this track has a filter that can be used to change the display mode, alter the color, and include/exclude a subset of items within the track. This may be helpful when many items are shown in the track display, especially when only some are relevant to the current task. To use the filter: Type a term in one or more of the text boxes to filter the EST display. For example, to apply the filter to all ESTs expressed in a specific organ, type the name of the organ in the tissue box. To view the list of valid terms for each text box, consult the table in the Table Browser that corresponds to the factor on which you wish to filter. For example, the "tissue" table contains all the types of tissues that can be entered into the tissue text box. Wildcards may also be used in the filter. If filtering on more than one value, choose the desired combination logic. If "and" is selected, only ESTs that match all filter criteria will be highlighted. If "or" is selected, ESTs that match any one of the filter criteria will be highlighted. Choose the color or display characteristic that should be used to highlight or include/exclude the filtered items. If "exclude" is chosen, the browser will not display ESTs that match the filter criteria. If "include" is selected, the browser will display only those ESTs that match the filter criteria. This track may also be configured to display base labeling, a feature that allows the user to display all bases in the aligning sequence or only those that differ from the genomic sequence. For more information about this option, click here. Methods To make an EST, RNA is isolated from cells and reverse transcribed into cDNA. Typically, the cDNA is cloned into a plasmid vector and a read is taken from the 5' and/or 3' primer. For most — but not all — ESTs, the reverse transcription is primed by an oligo-dT, which hybridizes with the poly-A tail of mature mRNA. The reverse transcriptase may or may not make it to the 5' end of the mRNA, which may or may not be degraded. In general, the 3' ESTs mark the end of transcription reasonably well, but the 5' ESTs may end at any point within the transcript. Some of the newer cap-selected libraries cover transcription start reasonably well. Before the cap-selection techniques emerged, some projects used random rather than poly-A priming in an attempt to retrieve sequence distant from the 3' end. These projects were successful at this, but as a side effect also deposited sequences from unprocessed mRNA and perhaps even genomic sequences into the EST databases. Even outside of the random-primed projects, there is a degree of non-mRNA contamination. Because of this, a single unspliced EST should be viewed with considerable skepticism. To generate this track, D. melanogaster ESTs from GenBank were aligned against the genome using blat. Note that the maximum intron length allowed by blat is 750,000 bases, which may eliminate some ESTs with very long introns that might otherwise align. When a single EST aligned in multiple places, the alignment having the highest base identity was identified. Only alignments having a base identity level within 0.5% of the best and at least 96% base identity with the genomic sequence are displayed in this track. Credits This track was produced at UCSC from EST sequence data submitted to the international public sequence databases by scientists worldwide. References Benson DA, Karsch-Mizrachi I, Lipman DJ, Ostell J, Wheeler DL. GenBank: update. Nucleic Acids Res. 2004 Jan 1;32(Database issue):D23-6. PMID: 14681350; PMC: PMC308779 Kent WJ. BLAT - the BLAST-like alignment tool. Genome Res. 2002 Apr;12(4):656-64. PMID: 11932250; PMC: PMC187518 
mrna D. melanogaster mRNAs D. melanogaster mRNAs from GenBank mRNA and EST Description The mRNA track shows alignments between D. melanogaster mRNAs in GenBank and the genome. Display Conventions and Configuration This track follows the display conventions for PSL alignment tracks. In dense display mode, the items that are more darkly shaded indicate matches of better quality. The description page for this track has a filter that can be used to change the display mode, alter the color, and include/exclude a subset of items within the track. This may be helpful when many items are shown in the track display, especially when only some are relevant to the current task. To use the filter: Type a term in one or more of the text boxes to filter the mRNA display. For example, to apply the filter to all mRNAs expressed in a specific organ, type the name of the organ in the tissue box. To view the list of valid terms for each text box, consult the table in the Table Browser that corresponds to the factor on which you wish to filter. For example, the "tissue" table contains all the types of tissues that can be entered into the tissue text box. Wildcards may also be used in the filter. If filtering on more than one value, choose the desired combination logic. If "and" is selected, only mRNAs that match all filter criteria will be highlighted. If "or" is selected, mRNAs that match any one of the filter criteria will be highlighted. Choose the color or display characteristic that should be used to highlight or include/exclude the filtered items. If "exclude" is chosen, the browser will not display mRNAs that match the filter criteria. If "include" is selected, the browser will display only those mRNAs that match the filter criteria. This track may also be configured to display codon coloring, a feature that allows the user to quickly compare mRNAs against the genomic sequence. For more information about this option, click here. Methods GenBank D. melanogaster mRNAs were aligned against the genome using the blat program. When a single mRNA aligned in multiple places, the alignment having the highest base identity was found. Only alignments having a base identity level within 0.5% of the best and at least 96% base identity with the genomic sequence were kept. Credits The mRNA track was produced at UCSC from mRNA sequence data submitted to the international public sequence databases by scientists worldwide. References Benson DA, Karsch-Mizrachi I, Lipman DJ, Ostell J, Wheeler DL. GenBank: update. Nucleic Acids Res. 2004 Jan 1;32(Database issue):D23-6. PMID: 14681350; PMC: PMC308779 Kent WJ. BLAT - the BLAST-like alignment tool. Genome Res. 2002 Apr;12(4):656-64. PMID: 11932250; PMC: PMC187518 
gap Gap Gap Locations Mapping and Sequencing Description This track depicts gaps — represented by black boxes — in the D. melanogaster genome sequence. An assembly region is designated as a gap if the sequence contains a series of Ns. The minimum number of Ns that constitute a gap varies among assemblies. 
gcPercent GC Percent Percentage GC in 20,000-Base Windows Mapping and Sequencing Description The GC percent track shows the percentage of G (guanine) and C (cytosine) bases in a 20,000 base window. Windows with high GC content are drawn more darkly than windows with low GC content. High GC content is typically associated with gene-rich areas. Credits This track was generated at UCSC. 
genscan Genscan Genes Genscan Gene Predictions Genes and Gene Predictions Description This track shows predictions from the Genscan program written by Chris Burge. The predictions are based on transcriptional, translational and donor/acceptor splicing signals as well as the length and compositional distributions of exons, introns and intergenic regions. For more information on the different gene tracks, see our Genes FAQ. Display Conventions and Configuration This track follows the display conventions for gene prediction tracks. The track description page offers the following filter and configuration options: Color track by codons: Select the genomic codons option to color and label each codon in a zoomed-in display to facilitate validation and comparison of gene predictions. Go to the Coloring Gene Predictions and Annotations by Codon page for more information about this feature. Methods For a description of the Genscan program and the model that underlies it, refer to Burge and Karlin (1997) in the References section below. The splice site models used are described in more detail in Burge (1998) below. Credits Thanks to Chris Burge for providing the Genscan program. References Burge C. Modeling Dependencies in Pre-mRNA Splicing Signals. In: Salzberg S, Searls D, Kasif S, editors. Computational Methods in Molecular Biology. Amsterdam: Elsevier Science; 1998. p. 127-163. Burge C, Karlin S. Prediction of complete gene structures in human genomic DNA. J. Mol. Biol. 1997 Apr 25;268(1):78-94. PMID: 9149143 
blastHg16KG Human Proteins Human Proteins (hg16) Mapped by Chained tBLASTn Genes and Gene Predictions Description This track contains tBLASTn alignments of the peptides from the predicted and known genes identified in the hg16 Known Genes track. Methods First, the predicted proteins from the human Known Genes track were aligned with the human genome using the Blat program to discover exon boundaries. Next, the amino acid sequences that make up each exon were aligned with the D. melanogaster sequence using the tBLASTn program. Finally, the putative D. melanogaster exons were chained together using an organism-specific maximum gap size but no gap penalty. The single best exon chains extending over more than 60% of the query protein were included. Exon chains that extended over 60% of the query and matched at least 60% of the protein's amino acids were also included. Credits tBLASTn is part of the NCBI BLAST tool set. For more information on BLAST, see Altschul SF, Gish W, Miller W, Myers EW, Lipman DJ. Basic local alignment search tool. J Mol Biol. 1990 Oct 5;215(3):403-410. Blat was written by Jim Kent. The remaining utilities used to produce this track were written by Jim Kent or Brian Raney. 
microsat Microsatellite Microsatellites - Di-nucleotide and Tri-nucleotide Repeats Variation and Repeats Description This track displays regions that are likely to be useful as microsatellite markers. These are sequences of at least 15 perfect di-nucleotide and tri-nucleotide repeats and tend to be highly polymorphic in the population. Methods The data shown in this track are a subset of the Simple Repeats track, selecting only those repeats of period 2 and 3, with 100% identity and no indels and with at least 15 copies of the repeat. The Simple Repeats track is created using the Tandem Repeats Finder. For more information about this program, see Benson (1999). Credits Tandem Repeats Finder was written by Gary Benson. References Benson G. Tandem repeats finder: a program to analyze DNA sequences. Nucleic Acids Res. 1999 Jan 15;27(2):573-80. PMID: 9862982; PMC: PMC148217 
miRNA miRNA MicroRNAs from miRBase Genes and Gene Predictions Description The miRNA track shows microRNAs from miRBase. Display Conventions and Configuration Mature miRNAs (miRs) are represented by thick blocks. The predicted stem-loop portions of the primary transcripts are indicated by thinner blocks. miRNAs in the sense orientation are shown in black; those in the reverse orientation are colored grey. When a single precursor produces two mature miRs from its 5' and 3' parts, it is displayed twice with the two different positions of the mature miR. To display only those items that exceed a specific unnormalized score, enter a minimum score between 0 and 1000 in the text box at the top of the track description page. Methods Mature and precursor miRNAs from the miRNA Registry were aligned against the genome using blat. The extents of the precursor sequences were not generally known, and were predicted based on base-paired hairpin structure. miRBase is described in Griffiths-Jones, S. et al. (2006). The miRNA Registry is described in Griffiths-Jones, S. (2004) and Weber, M.J. (2005) in the References section below. Credits This track was created by Michel Weber of Laboratoire de Biologie Moléculaire Eucaryote, CNRS Université Paul Sabatier (Toulouse, France), Yves Quentin of Laboratoire de Microbiologie et Génétique Moléculaires (Toulouse, France) and Sam Griffiths-Jones of The Wellcome Trust Sanger Institute (Cambridge, UK). References When making use of these data, please cite: Griffiths-Jones S, Grocock RJ, van Dongen S, Bateman A, Enright AJ. miRBase: microRNA sequences, targets and gene nomenclature. Nucleic Acids Res. 2006 Jan 1;34(Database issue):D140-4. PMID: 16381832; PMC: PMC1347474 Griffiths-Jones S. The microRNA Registry. Nucleic Acids Res. 2004 Jan 1;32(Database issue):D109-11. PMID: 14681370; PMC: PMC308757 Weber MJ. New human and mouse microRNA genes found by homology search. FEBS J. 2005 Jan;272(1):59-73. PMID: 15634332 The following publication provides guidelines on miRNA annotation: Ambros V, Bartel B, Bartel DP, Burge CB, Carrington JC, Chen X, Dreyfuss G, Eddy SR, Griffiths-Jones S, Marshall M et al. A uniform system for microRNA annotation. RNA. 2003 Mar;9(3):277-9. PMID: 12592000; PMC: PMC1370393 For more information on blat, see Kent WJ. BLAT - the BLAST-like alignment tool. Genome Res. 2002 Apr;12(4):656-64. PMID: 11932250; PMC: PMC187518 
xenoRefGene Other RefSeq Non-D. melanogaster RefSeq Genes Genes and Gene Predictions Description This track shows known protein-coding and non-protein-coding genes for organisms other than D. melanogaster, taken from the NCBI RNA reference sequences collection (RefSeq). The data underlying this track are updated weekly. Display Conventions and Configuration This track follows the display conventions for gene prediction tracks. The color shading indicates the level of review the RefSeq record has undergone: predicted (light), provisional (medium), reviewed (dark). The item labels and display colors of features within this track can be configured through the controls at the top of the track description page. Label: By default, items are labeled by gene name. Click the appropriate Label option to display the accession name instead of the gene name, show both the gene and accession names, or turn off the label completely. Codon coloring: This track contains an optional codon coloring feature that allows users to quickly validate and compare gene predictions. To display codon colors, select the genomic codons option from the Color track by codons pull-down menu. Click here for more information about this feature. Hide non-coding genes: By default, both the protein-coding and non-protein-coding genes are displayed. If you wish to see only the coding genes, click this box. Methods The RNAs were aligned against the D. melanogaster genome using blat; those with an alignment of less than 15% were discarded. When a single RNA aligned in multiple places, the alignment having the highest base identity was identified. Only alignments having a base identity level within 0.5% of the best and at least 25% base identity with the genomic sequence were kept. Credits This track was produced at UCSC from RNA sequence data generated by scientists worldwide and curated by the NCBI RefSeq project. References Kent WJ. BLAT - the BLAST-like alignment tool. Genome Res. 2002 Apr;12(4):656-64. PMID: 11932250; PMC: PMC187518 
genomicSuperDups Segmental Dups Duplications of >1000 Bases of Non-RepeatMasked Sequence Variation and Repeats Description This track shows regions detected as putative genomic duplications within the golden path. The following display conventions are used to distinguish levels of similarity: Light to dark gray: 90 - 98% similarity Light to dark yellow: 98 - 99% similarity Light to dark orange: greater than 99% similarity Red: duplications of greater than 98% similarity that lack sufficient Segmental Duplication Database evidence (most likely missed overlaps) For a region to be included in the track, at least 1 Kb of the total sequence (containing at least 500 bp of non-RepeatMasked sequence) had to align and a sequence identity of at least 90% was required. Methods Segmental duplications play an important role in both genomic disease and gene evolution. This track displays an analysis of the global organization of these long-range segments of identity in genomic sequence. Large recent duplications (>= 1 kb and >= 90% identity) were detected by identifying high-copy repeats, removing these repeats from the genomic sequence ("fuguization") and searching all sequence for similarity. The repeats were then reinserted into the pairwise alignments, the ends of alignments trimmed, and global alignments were generated. For a full description of the "fuguization" detection method, see Bailey et al., 2001. This method has become known as WGAC (whole-genome assembly comparison); for example, see Bailey et al., 2002. Credits These data were provided by Ginger Cheng, Xinwei She, Archana Raja, Tin Louie and Evan Eichler at the University of Washington. References Bailey JA, Gu Z, Clark RA, Reinert K, Samonte RV, Schwartz S, Adams MD, Myers EW, Li PW, Eichler EE. Recent segmental duplications in the human genome. Science. 2002 Aug 9;297(5583):1003-7. PMID: 12169732 Bailey JA, Yavor AM, Massa HF, Trask BJ, Eichler EE. Segmental duplications: organization and impact within the current human genome project assembly. Genome Res. 2001 Jun;11(6):1005-17. PMID: 11381028; PMC: PMC311093 
simpleRepeat Simple Repeats Simple Tandem Repeats by TRF Variation and Repeats Description This track displays simple tandem repeats (possibly imperfect repeats) located by Tandem Repeats Finder (TRF) which is specialized for this purpose. These repeats can occur within coding regions of genes and may be quite polymorphic. Repeat expansions are sometimes associated with specific diseases. Methods For more information about the TRF program, see Benson (1999). Credits TRF was written by Gary Benson. References Benson G. Tandem repeats finder: a program to analyze DNA sequences. Nucleic Acids Res. 1999 Jan 15;27(2):573-80. PMID: 9862982; PMC: PMC148217 
twinscan Twinscan Twinscan Gene Predictions Using D. melanogaster/pseudoobscura Homology Genes and Gene Predictions Description The Twinscan program predicts genes in a manner similar to Genscan, except that Twinscan takes advantage of genome comparisons to improve gene prediction accuracy. More information and a web server can be found at http://mblab.wustl.edu/. Display Conventions and Configuration This track follows the display conventions for gene prediction tracks. The track description page offers the following filter and configuration options: Color track by codons: Select the genomic codons option to color and label each codon in a zoomed-in display to facilitate validation and comparison of gene predictions. Click the Help on codon coloring link on the track description page for more information about this feature. Methods The Twinscan algorithm is described in Korf, I. et al. (2001) in the References section below. Credits Thanks to Michael Brent's Computational Genomics Group at Washington University St. Louis for providing these data. References Korf I, Flicek P, Duan D, Brent MR. Integrating genomic homology into gene structure prediction. Bioinformatics. 2001;17 Suppl 1:S140-8. PMID: 11473003 
blatFugu Fugu Blat Fugu (Aug. 2002 (JGI 3.0/fr1)) Translated Blat Alignments Comparative Genomics Description The Fugu v.3.0 whole genome shotgun assembly was provided by the US DOE Joint Genome Institute (JGI). The assembly was constructed with the JGI assembler, JAZZ, from paired end sequencing reads produced at JGI, Myriad Genetics, and Celera Genomics, resulting in a sequence coverage of 5.7X. All reads are plasmid, cosmid, or BAC end-sequences, with the predominant coverage derived from 2 Kb insert plasmids. This assembly contains 20,379 scaffolds totaling 319 million base pairs. The largest 679 scaffolds total 160 million base pairs. The strand information (+/-) for this track is in two parts. The first + or - indicates the orientation of the query sequence whose translated protein produced the match. The second + or - indicates the orientation of the matching translated genomic sequence. Because the two orientations of a DNA sequence give different predicted protein sequences, there are four combinations. ++ is not the same as --; nor is +- the same as -+. Methods The alignments were made with blat in translated protein mode requiring two nearby 4-mer matches to trigger a detailed alignment. The D. melanogaster genome was masked with RepeatMasker and Tandem Repeat Finder before running blat. Credits The 3.0 draft from the JGI Fugu rubripes website was used in the UCSC Genome Browser Fugu blat alignments. These data were freely provided by the JGI for use in this publication only. References Kent WJ. BLAT--the BLAST-like alignment tool. Genome Res. 2002 Apr;12(4):656-64. PMID: 11932250; PMC: PMC187518 
anophelesEcores Anopheles Ecores D. melanogaster/A. gambiae (Feb. 2003 (IAGEC MOZ2/anoGam1)) Evolutionary Conserved Regions Comparative Genomics Description This track shows Evolutionary Conserved Regions computed by the Exofish (Roest et al., 2000) program at Genoscope. Each singleton block corresponds to an "ecore"; two blocks connected by a thin line correspond to an "ecotig", a set of colinear ecores in a syntenic region. Methods Genome-wide sequence comparisons were done at the protein-coding level between the genome sequences of the fruitfly, Drosophila melanogaster and the mosquito, Anopheles gambiae to detect evolutionarily conserved regions (ECORES). See Jaillon et al., 2003. The sequence versions used in the comparison were Ensembl Drosophila v.16.3a.1 (Jan. 2003, the same as BDGP Release 3.1 used by the UCSC Genome Browser) and Ensembl Anopheles v.16.2.1 . Credits Thanks to Olivier Jaillon at Genoscope for contributing the data. References Jaillon O, Dossat C, Eckenberg R, Eiglmeier K, Segurens B, Aury JM, Roth CW, Scarpelli C, Brey PT, Weissenbach J et al. Assessing the Drosophila melanogaster and Anopheles gambiae genome annotations using genome-wide sequence comparisons. Genome Res. 2003 Jul;13(7):1595-9. PMID: 12840038; PMC: PMC403732 Roest Crollius H, Jaillon O, Bernot A, Dasilva C, Bouneau L, Fischer C, Fizames C, Wincker P, Brottier P, Quétier F et al. Estimate of human gene number provided by genome-wide analysis using Tetraodon nigroviridis DNA sequence. Nat Genet. 2000 Jun;25(2):235-8. PMID: 10835645 
chainAnoGam1 A. gambiae Chain A. gambiae (Feb. 2003 (IAGEC MOZ2/anoGam1)) Chained Alignments Comparative Genomics Description This track shows alignments of A. gambiae (anoGam1, Feb. 2003 (IAGEC MOZ2/anoGam1)) to the D. melanogaster genome using a gap scoring system that allows longer gaps than traditional affine gap scoring systems. It can also tolerate gaps in both A. gambiae and D. melanogaster simultaneously. These "double-sided" gaps can be caused by local inversions and overlapping deletions in both species. The A. gambiae sequence is from the MOZ2 assembly. The chain track displays boxes joined together by either single or double lines. The boxes represent aligning regions. Single lines indicate gaps that are largely due to a deletion in the A. gambiae assembly or an insertion in the D. melanogaster assembly. Double lines represent more complex gaps that involve substantial sequence in both species. This may result from inversions, overlapping deletions, an abundance of local mutation, or an unsequenced gap in one species. In cases where multiple chains align over a particular region of the D. melanogaster genome, the chains with single-lined gaps are often due to processed pseudogenes, while chains with double-lined gaps are more often due to paralogs and unprocessed pseudogenes. In the "pack" and "full" display modes, the individual feature names indicate the chromosome, strand, and location (in thousands) of the match for each matching alignment. Display Conventions and Configuration By default, the chains to chromosome-based assemblies are colored based on which chromosome they map to in the aligning organism. To turn off the coloring, check the "off" button next to: Color track based on chromosome. To display only the chains of one chromosome in the aligning organism, enter the name of that chromosome (e.g. chr4) in box next to: Filter by chromosome. Methods The A. gambiae/D. melanogaster genomes were aligned with blastz and converted into axt format using the lavToAxt program. The axt alignments were fed into axtChain, which organizes all alignments between a single A. gambiae chromosome and a single D. melanogaster chromosome into a group and creates a kd-tree out of the gapless subsections (blocks) of the alignments. A dynamic program was then run over the kd-trees to find the maximally scoring chains of these blocks. The following matrix was used:  ACGT A91-90-25-100 C-90100-100-25 G-25-100100-90 T-100-25-9091 Chains scoring below a threshold were discarded; the remaining chains are displayed in this track. Credits Blastz was developed at Pennsylvania State University by Minmei Hou, Scott Schwartz, Zheng Zhang, and Webb Miller with advice from Ross Hardison. Lineage-specific repeats were identified by Arian Smit and his RepeatMasker program. The axtChain program was developed at the University of California at Santa Cruz by Jim Kent with advice from Webb Miller and David Haussler. The browser display and database storage of the chains were generated by Robert Baertsch and Jim Kent. References Chiaromonte F, Yap VB, Miller W. Scoring pairwise genomic sequence alignments. Pac Symp Biocomput. 2002:115-26. PMID: 11928468 Kent WJ, Baertsch R, Hinrichs A, Miller W, Haussler D. Evolution's cauldron: duplication, deletion, and rearrangement in the mouse and human genomes. Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11484-9. PMID: 14500911; PMC: PMC208784 Schwartz S, Kent WJ, Smit A, Zhang Z, Baertsch R, Hardison RC, Haussler D, Miller W. Human-mouse alignments with BLASTZ. Genome Res. 2003 Jan;13(1):103-7. PMID: 12529312; PMC: PMC430961 
netAnoGam1 A. gambiae Net A. gambiae (Feb. 2003 (IAGEC MOZ2/anoGam1)) Alignment Net Comparative Genomics Description This track shows the best A. gambiae/D. melanogaster chain for every part of the D. melanogaster genome. It is useful for finding orthologous regions and for studying genome rearrangement. The A. gambiae sequence used in this annotation is from the Feb. 2003 (IAGEC MOZ2/anoGam1) (anoGam1) assembly. Display Conventions and Configuration In full display mode, the top-level (level 1) chains are the largest, highest-scoring chains that span this region. In many cases gaps exist in the top-level chain. When possible, these are filled in by other chains that are displayed at level 2. The gaps in level 2 chains may be filled by level 3 chains and so forth. In the graphical display, the boxes represent ungapped alignments; the lines represent gaps. Click on a box to view detailed information about the chain as a whole; click on a line to display information about the gap. The detailed information is useful in determining the cause of the gap or, for lower level chains, the genomic rearrangement. Individual items in the display are categorized as one of four types (other than gap): Top - the best, longest match. Displayed on level 1. Syn - line-ups on the same chromosome as the gap in the level above it. Inv - a line-up on the same chromosome as the gap above it, but in the opposite orientation. NonSyn - a match to a chromosome different from the gap in the level above. Methods Chains were derived from blastz alignments, using the methods described on the chain tracks description pages, and sorted with the highest-scoring chains in the genome ranked first. The program chainNet was then used to place the chains one at a time, trimming them as necessary to fit into sections not already covered by a higher-scoring chain. During this process, a natural hierarchy emerged in which a chain that filled a gap in a higher-scoring chain was placed underneath that chain. The program netSyntenic was used to fill in information about the relationship between higher- and lower-level chains, such as whether a lower-level chain was syntenic or inverted relative to the higher-level chain. The program netClass was then used to fill in how much of the gaps and chains contained Ns (sequencing gaps) in one or both species and how much was filled with transposons inserted before and after the two organisms diverged. Credits The chainNet, netSyntenic, and netClass programs were developed at the University of California Santa Cruz by Jim Kent. Blastz was developed at Pennsylvania State University by Minmei Hou, Scott Schwartz, Zheng Zhang, and Webb Miller with advice from Ross Hardison. Lineage-specific repeats were identified by Arian Smit and his program RepeatMasker. The browser display and database storage of the nets were made by Robert Baertsch and Jim Kent. References Kent WJ, Baertsch R, Hinrichs A, Miller W, Haussler D. Evolution's cauldron: duplication, deletion, and rearrangement in the mouse and human genomes. Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11484-9. PMID: 14500911; PMC: PMC208784 Schwartz S, Kent WJ, Smit A, Zhang Z, Baertsch R, Hardison RC, Haussler D, Miller W. Human-mouse alignments with BLASTZ. Genome Res. 2003 Jan;13(1):103-7. PMID: 12529312; PMC: PMC430961 
chainDp2 D. pseudo. Chain D. pseudoobscura (Aug. 2003 (Baylor freeze1/dp2)) Chained Alignments Comparative Genomics Description This track shows alignments of D. pseudoobscura (dp2, Aug. 2003 (Baylor freeze1/dp2)) to the D. melanogaster genome using a gap scoring system that allows longer gaps than traditional affine gap scoring systems. It can also tolerate gaps in both D. pseudoobscura and D. melanogaster simultaneously. These "double-sided" gaps can be caused by local inversions and overlapping deletions in both species. The chain track displays boxes joined together by either single or double lines. The boxes represent aligning regions. Single lines indicate gaps that are largely due to a deletion in the D. pseudoobscura assembly or an insertion in the D. melanogaster assembly. Double lines represent more complex gaps that involve substantial sequence in both species. This may result from inversions, overlapping deletions, an abundance of local mutation, or an unsequenced gap in one species. In cases where multiple chains align over a particular region of the D. melanogaster genome, the chains with single-lined gaps are often due to processed pseudogenes, while chains with double-lined gaps are more often due to paralogs and unprocessed pseudogenes. In the "pack" and "full" display modes, the individual feature names indicate the chromosome, strand, and location (in thousands) of the match for each matching alignment. Display Conventions and Configuration By default, the chains to chromosome-based assemblies are colored based on which chromosome they map to in the aligning organism. To turn off the coloring, check the "off" button next to: Color track based on chromosome. To display only the chains of one chromosome in the aligning organism, enter the name of that chromosome (e.g. chr4) in box next to: Filter by chromosome. Methods The D. pseudoobscura/D. melanogaster genomes were aligned with blastz and converted into axt format using the lavToAxt program. The axt alignments were fed into axtChain, which organizes all alignments between a single D. pseudoobscura chromosome and a single D. melanogaster chromosome into a group and creates a kd-tree out of the gapless subsections (blocks) of the alignments. A dynamic program was then run over the kd-trees to find the maximally scoring chains of these blocks. Chains scoring below a threshold were discarded; the remaining chains are displayed in this track. Credits Blastz was developed at Pennsylvania State University by Minmei Hou, Scott Schwartz, Zheng Zhang, and Webb Miller with advice from Ross Hardison. Lineage-specific repeats were identified by Arian Smit and his RepeatMasker program. The axtChain program was developed at the University of California at Santa Cruz by Jim Kent with advice from Webb Miller and David Haussler. The browser display and database storage of the chains were generated by Robert Baertsch and Jim Kent. References Chiaromonte F, Yap VB, Miller W. Scoring pairwise genomic sequence alignments. Pac Symp Biocomput. 2002:115-26. PMID: 11928468 Kent WJ, Baertsch R, Hinrichs A, Miller W, Haussler D. Evolution's cauldron: duplication, deletion, and rearrangement in the mouse and human genomes. Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11484-9. PMID: 14500911; PMC: PMC208784 Schwartz S, Kent WJ, Smit A, Zhang Z, Baertsch R, Hardison RC, Haussler D, Miller W. Human-mouse alignments with BLASTZ. Genome Res. 2003 Jan;13(1):103-7. PMID: 12529312; PMC: PMC430961 
netDp2 D. pseudo. Net D. pseudoobscura (Aug. 2003 (Baylor freeze1/dp2)) Alignment Net Comparative Genomics Description This track shows the best D. pseudoobscura/D. melanogaster chain for every part of the D. melanogaster genome. It is useful for finding orthologous regions and for studying genome rearrangement. The D. pseudoobscura sequence used in this annotation is from the Aug. 2003 (Baylor freeze1/dp2) (dp2) assembly. Display Conventions and Configuration In full display mode, the top-level (level 1) chains are the largest, highest-scoring chains that span this region. In many cases gaps exist in the top-level chain. When possible, these are filled in by other chains that are displayed at level 2. The gaps in level 2 chains may be filled by level 3 chains and so forth. In the graphical display, the boxes represent ungapped alignments; the lines represent gaps. Click on a box to view detailed information about the chain as a whole; click on a line to display information about the gap. The detailed information is useful in determining the cause of the gap or, for lower level chains, the genomic rearrangement. Individual items in the display are categorized as one of four types (other than gap): Top - the best, longest match. Displayed on level 1. Syn - line-ups on the same chromosome as the gap in the level above it. Inv - a line-up on the same chromosome as the gap above it, but in the opposite orientation. NonSyn - a match to a chromosome different from the gap in the level above. Methods Chains were derived from blastz alignments, using the methods described on the chain tracks description pages, and sorted with the highest-scoring chains in the genome ranked first. The program chainNet was then used to place the chains one at a time, trimming them as necessary to fit into sections not already covered by a higher-scoring chain. During this process, a natural hierarchy emerged in which a chain that filled a gap in a higher-scoring chain was placed underneath that chain. The program netSyntenic was used to fill in information about the relationship between higher- and lower-level chains, such as whether a lower-level chain was syntenic or inverted relative to the higher-level chain. The program netClass was then used to fill in how much of the gaps and chains contained Ns (sequencing gaps) in one or both species and how much was filled with transposons inserted before and after the two organisms diverged. Credits The Aug. 2003 dp2 data were obtained from the Freeze 1 assembly produced by the Human Genome Sequencing Center at Baylor School of Medicine. The chainNet, netSyntenic, and netClass programs were developed at the University of California Santa Cruz by Jim Kent. Blastz was developed at Pennsylvania State University by Minmei Hou, Scott Schwartz, Zheng Zhang, and Webb Miller with advice from Ross Hardison. Lineage-specific repeats were identified by Arian Smit and his program RepeatMasker. The browser display and database storage of the nets were made by Robert Baertsch and Jim Kent. References Kent WJ, Baertsch R, Hinrichs A, Miller W, Haussler D. Evolution's cauldron: duplication, deletion, and rearrangement in the mouse and human genomes. Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11484-9. PMID: 14500911; PMC: PMC208784 Schwartz S, Kent WJ, Smit A, Zhang Z, Baertsch R, Hardison RC, Haussler D, Miller W. Human-mouse alignments with BLASTZ. Genome Res. 2003 Jan;13(1):103-7. PMID: 12529312; PMC: PMC430961 
chainDroYak1 D. yakuba Chain D. yakuba (Apr. 2004 (WUGSC 1.0/droYak1)) Chained Alignments Comparative Genomics Description This track shows alignments of D. yakuba (droYak1, Apr. 2004 (WUGSC 1.0/droYak1)) to the D. melanogaster genome using a gap scoring system that allows longer gaps than traditional affine gap scoring systems. It can also tolerate gaps in both D. yakuba and D. melanogaster simultaneously. These "double-sided" gaps can be caused by local inversions and overlapping deletions in both species. The chain track displays boxes joined together by either single or double lines. The boxes represent aligning regions. Single lines indicate gaps that are largely due to a deletion in the D. yakuba assembly or an insertion in the D. melanogaster assembly. Double lines represent more complex gaps that involve substantial sequence in both species. This may result from inversions, overlapping deletions, an abundance of local mutation, or an unsequenced gap in one species. In cases where multiple chains align over a particular region of the D. melanogaster genome, the chains with single-lined gaps are often due to processed pseudogenes, while chains with double-lined gaps are more often due to paralogs and unprocessed pseudogenes. In the "pack" and "full" display modes, the individual feature names indicate the chromosome, strand, and location (in thousands) of the match for each matching alignment. Display Conventions and Configuration By default, the chains to chromosome-based assemblies are colored based on which chromosome they map to in the aligning organism. To turn off the coloring, check the "off" button next to: Color track based on chromosome. To display only the chains of one chromosome in the aligning organism, enter the name of that chromosome (e.g. chr4) in box next to: Filter by chromosome. Methods The D. yakuba/D. melanogaster genomes were aligned with blastz and converted into axt format using the lavToAxt program. The axt alignments were fed into axtChain, which organizes all alignments between a single D. yakuba chromosome and a single D. melanogaster chromosome into a group and creates a kd-tree out of the gapless subsections (blocks) of the alignments. A dynamic program was then run over the kd-trees to find the maximally scoring chains of these blocks. Chains scoring below a threshold were discarded; the remaining chains are displayed in this track. Credits Blastz was developed at Pennsylvania State University by Minmei Hou, Scott Schwartz, Zheng Zhang, and Webb Miller with advice from Ross Hardison. Lineage-specific repeats were identified by Arian Smit and his RepeatMasker program. The axtChain program was developed at the University of California at Santa Cruz by Jim Kent with advice from Webb Miller and David Haussler. The browser display and database storage of the chains were generated by Robert Baertsch and Jim Kent. References Chiaromonte F, Yap VB, Miller W. Scoring pairwise genomic sequence alignments. Pac Symp Biocomput. 2002:115-26. PMID: 11928468 Kent WJ, Baertsch R, Hinrichs A, Miller W, Haussler D. Evolution's cauldron: duplication, deletion, and rearrangement in the mouse and human genomes. Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11484-9. PMID: 14500911; PMC: PMC208784 Schwartz S, Kent WJ, Smit A, Zhang Z, Baertsch R, Hardison RC, Haussler D, Miller W. Human-mouse alignments with BLASTZ. Genome Res. 2003 Jan;13(1):103-7. PMID: 12529312; PMC: PMC430961 
netDroYak1 D. yakuba Net D. yakuba (Apr. 2004 (WUGSC 1.0/droYak1)) Alignment Net Comparative Genomics Description This track shows the best D. yakuba/D. melanogaster chain for every part of the D. melanogaster genome. It is useful for finding orthologous regions and for studying genome rearrangement. The D. yakuba sequence used in this annotation is from the Apr. 2004 (WUGSC 1.0/droYak1) (droYak1) assembly. Display Conventions and Configuration In full display mode, the top-level (level 1) chains are the largest, highest-scoring chains that span this region. In many cases gaps exist in the top-level chain. When possible, these are filled in by other chains that are displayed at level 2. The gaps in level 2 chains may be filled by level 3 chains and so forth. In the graphical display, the boxes represent ungapped alignments; the lines represent gaps. Click on a box to view detailed information about the chain as a whole; click on a line to display information about the gap. The detailed information is useful in determining the cause of the gap or, for lower level chains, the genomic rearrangement. Individual items in the display are categorized as one of four types (other than gap): Top - the best, longest match. Displayed on level 1. Syn - line-ups on the same chromosome as the gap in the level above it. Inv - a line-up on the same chromosome as the gap above it, but in the opposite orientation. NonSyn - a match to a chromosome different from the gap in the level above. Methods Chains were derived from blastz alignments, using the methods described on the chain tracks description pages, and sorted with the highest-scoring chains in the genome ranked first. The program chainNet was then used to place the chains one at a time, trimming them as necessary to fit into sections not already covered by a higher-scoring chain. During this process, a natural hierarchy emerged in which a chain that filled a gap in a higher-scoring chain was placed underneath that chain. The program netSyntenic was used to fill in information about the relationship between higher- and lower-level chains, such as whether a lower-level chain was syntenic or inverted relative to the higher-level chain. The program netClass was then used to fill in how much of the gaps and chains contained Ns (sequencing gaps) in one or both species and how much was filled with transposons inserted before and after the two organisms diverged. Credits The chainNet, netSyntenic, and netClass programs were developed at the University of California Santa Cruz by Jim Kent. Blastz was developed at Pennsylvania State University by Minmei Hou, Scott Schwartz, Zheng Zhang, and Webb Miller with advice from Ross Hardison. Lineage-specific repeats were identified by Arian Smit and his program RepeatMasker. The browser display and database storage of the nets were made by Robert Baertsch and Jim Kent. References Kent WJ, Baertsch R, Hinrichs A, Miller W, Haussler D. Evolution's cauldron: duplication, deletion, and rearrangement in the mouse and human genomes. Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11484-9. PMID: 14500911; PMC: PMC208784 Schwartz S, Kent WJ, Smit A, Zhang Z, Baertsch R, Hardison RC, Haussler D, Miller W. Human-mouse alignments with BLASTZ. Genome Res. 2003 Jan;13(1):103-7. PMID: 12529312; PMC: PMC430961 
rmsk RepeatMasker Repeating Elements by RepeatMasker Variation and Repeats Description This track was created by using Arian Smit's RepeatMasker program, which screens DNA sequences for interspersed repeats and low complexity DNA sequences. The program outputs a detailed annotation of the repeats that are present in the query sequence (represented by this track), as well as a modified version of the query sequence in which all the annotated repeats have been masked (generally available on the Downloads page). RepeatMasker uses the Repbase Update library of repeats from the Genetic Information Research Institute (GIRI). Repbase Update is described in Jurka, J. (2000) in the References section below. Display Conventions and Configuration In full display mode, this track displays up to ten different classes of repeats: Short interspersed nuclear elements (SINE), which include ALUs Long interspersed nuclear elements (LINE) Long terminal repeat elements (LTR), which include retroposons DNA repeat elements (DNA) Simple repeats (micro-satellites) Low complexity repeats Satellite repeats RNA repeats (including RNA, tRNA, rRNA, snRNA, scRNA) Other repeats, which includes class RC (Rolling Circle) Unknown The level of color shading in the graphical display reflects the amount of base mismatch, base deletion, and base insertion associated with a repeat element. The higher the combined number of these, the lighter the shading. Methods UCSC has used the most current versions of the RepeatMasker software and repeat libraries available to generate these data. Note that these versions may be newer than those that are publicly available on the Internet. Data are generated using the RepeatMasker -s flag. Additional flags may be used for certain organisms. Repeats are soft-masked. Alignments may extend through repeats, but are not permitted to initiate in them. See the FAQ for more information. Credits Thanks to Arian Smit and GIRI for providing the tools and repeat libraries used to generate this track. References Jurka J. Repbase update: a database and an electronic journal of repetitive elements. Trends Genet. 2000 Sep;16(9):418-20. PMID: 10973072