3bcdba0cb7f7281dc131c2c59684980741a841e6
mspeir
  Tue Dec 23 15:34:36 2025 -0800
Adding better description of species coloring in conservation tracks, refs #27217

diff --git src/hg/makeDb/trackDb/mouse/mm39/cons35way.html src/hg/makeDb/trackDb/mouse/mm39/cons35way.html
index 200e95a3513..56950ce1892 100644
--- src/hg/makeDb/trackDb/mouse/mm39/cons35way.html
+++ src/hg/makeDb/trackDb/mouse/mm39/cons35way.html
@@ -1,509 +1,511 @@
 <H2>Description</H2>
 <P>
 This track shows multiple alignments of 35 vertebrate
 species and measurements of evolutionary conservation using
 two methods (<em>phastCons</em> and <em>phyloP</em>) from the
 <A HREF="http://compgen.cshl.edu/phast/" target=_BLANK>
 PHAST package</A>.
 </P>
 <P>
 The multiple alignments were generated using multiz and
 other tools in the UCSC/<A HREF="http://www.bx.psu.edu/miller_lab/" 
 TARGET=_blank>Penn State Bioinformatics</A>
 comparative genomics alignment pipeline.
 Conserved elements identified by phastCons are also displayed in
 this track. 
 The conservation measurements were created using the phastCons package from
 <A HREF="https://siepellab.labsites.cshl.edu/" TARGET=_blank>
 Adam Siepel</A> at Cold Spring Harbor Laboratory. </P>
 Both phastCons and phyloP treat alignment gaps and unaligned nucleotides as
 missing data.
 </P>
 <P>
 See also: <A HREF="http://genomewiki.ucsc.edu/index.php/Mm39_35-way_conservation_lastz_parameters"
 TARGET=_blank>lastz parameters</A> and other details
 for the chaining <A HREF="http://genomewiki.ucsc.edu/index.php/Mm39_35-way_Genome_size_statistics"
 TARGET=_blank>minimum score and gap</A> parameters used in these alignments.
 </P>
 
 <P>
 PhastCons (which has been used in previous Conservation tracks) is a hidden
 Markov model-based method that estimates the probability that each
 nucleotide belongs to a conserved element, based on the multiple alignment.
 It considers not just each individual alignment column, but also its
 flanking columns.  By contrast, phyloP separately measures conservation at
 individual columns, ignoring the effects of their neighbors.  As a
 consequence, the phyloP plots have a less smooth appearance than the
 phastCons plots, with more "texture" at individual sites.  The two methods
 have different strengths and weaknesses.  PhastCons is sensitive to "runs"
 of conserved sites, and is therefore effective for picking out conserved
 elements.  PhyloP, on the other hand, is more appropriate for evaluating
 signatures of selection at particular nucleotides or classes of nucleotides
 (e.g., third codon positions, or first positions of miRNA target sites).
 </P>
 <P>
 Another important difference is that phyloP can measure acceleration
 (faster evolution than expected under neutral drift) as well as
 conservation (slower than expected evolution).  In the phyloP plots, sites
 predicted to be conserved are assigned positive scores (and shown in blue),
 while sites predicted to be fast-evolving are assigned negative scores (and
 shown in red).  The absolute values of the scores represent -log p-values
 under a null hypothesis of neutral evolution.  The phastCons scores, by
 contrast, represent probabilities of negative selection and range between 0
 and 1.
 </P>
 
 <P>
 Missing sequence in the assemblies is highlighted in the track display
 by regions of yellow when zoomed out and Ns displayed at base
 level (see <EM>Gap Annotation</EM>, below). </P>
 <P>
 <BLOCKQUOTE>
  <table cellpadding="4" class="descTbl">
 <tr align=left><td>Mouse</td><td>Mus musculus</td><td>
     Jun. 2020 (GRCm39/mm39)</td><td><a href="../cgi-bin/hgTracks?db=mm39"
     target=_blank>Jun. 2020 (GRCm39/mm39)</a></td><td>reference species</td></tr>
 <tr align=left><td>Beaver</td><td>Castor canadensis</td><td>
     Feb. 2017 (C.can genome v1.0/casCan1)</td><td><a href="../../h/GCF_001984765.1"
     target=_blank>Feb. 2017 (C.can genome v1.0/casCan1)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Bonobo</td><td>Pan paniscus</td><td>
     May 2020 (Mhudiblu_PPA_v0/panPan3)</td><td><a href="../cgi-bin/hgTracks?db=panPan3"
     target=_blank>May 2020 (Mhudiblu_PPA_v0/panPan3)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Bushbaby</td><td>Otolemur garnettii</td><td>
     Mar. 2011 (Broad/otoGar3)</td><td><a href="../cgi-bin/hgTracks?db=otoGar3"
     target=_blank>Mar. 2011 (Broad/otoGar3)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Chicken</td><td>Gallus gallus</td><td>
     Mar. 2018 (GRCg6a/galGal6)</td><td><a href="../cgi-bin/hgTracks?db=galGal6"
     target=_blank>Mar. 2018 (GRCg6a/galGal6)</a></td><td>maf net</td></tr>
 <tr align=left><td>Chimp</td><td>Pan troglodytes</td><td>
     Jan. 2018 (Clint_PTRv2/panTro6)</td><td><a href="../cgi-bin/hgTracks?db=panTro6"
     target=_blank>Jan. 2018 (Clint_PTRv2/panTro6)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Chinese hamster</td><td>Cricetulus griseus</td><td>
     Jun. 2020 (GCF_0003668045.3 CriGri-PICRH-1.0)</td><td><a href="https://hgdownload.soe.ucsc.edu/h/GCF_003668045.3"
     target=_blank>Jun. 2020 (GCF_0003668045.3 CriGri-PICRH-1.0)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Chinese pangolin</td><td>Manis pentadactyla</td><td>
     Aug 2014 (M_pentadactyla-1.1.1/manPen1)</td><td><a href="../cgi-bin/hgTracks?db=manPen1"
     target=_blank>Aug 2014 (M_pentadactyla-1.1.1/manPen1)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Cow</td><td>Bos taurus</td><td>
     Apr. 2018 (ARS-UCD1.2/bosTau9)</td><td><a href="../cgi-bin/hgTracks?db=bosTau9"
     target=_blank>Apr. 2018 (ARS-UCD1.2/bosTau9)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Dog</td><td>Canis lupus familiaris</td><td>
     Mar. 2020 (UU_Cfam_GSD_1.0/canFam4)</td><td><a href="../cgi-bin/hgTracks?db=canFam4"
     target=_blank>Mar. 2020 (UU_Cfam_GSD_1.0/canFam4)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Dolphin</td><td>Tursiops truncatus</td><td>
     Oct. 2011 (Baylor Ttru_1.4/turTru2)</td><td><a href="../cgi-bin/hgTracks?db=turTru2"
     target=_blank>Oct. 2011 (Baylor Ttru_1.4/turTru2)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Elephant</td><td>Loxodonta africana</td><td>
     Jul. 2009 (Broad/loxAfr3)</td><td><a href="../cgi-bin/hgTracks?db=loxAfr3"
     target=_blank>Jul. 2009 (Broad/loxAfr3)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Gorilla</td><td>Gorilla gorilla gorilla</td><td>
     Aug. 2019 (Kamilah_GGO_v0/gorGor6)</td><td><a href="../cgi-bin/hgTracks?db=gorGor6"
     target=_blank>Aug. 2019 (Kamilah_GGO_v0/gorGor6)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Guinea pig</td><td>Cavia porcellus</td><td>
     Feb. 2008 (Broad/cavPor3)</td><td><a href="../cgi-bin/hgTracks?db=cavPor3"
     target=_blank>Feb. 2008 (Broad/cavPor3)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Hawaiian monk seal</td><td>Neomonachus schauinslandi</td><td>
     Jun. 2017 (ASM220157v1/neoSch1)</td><td><a href="../cgi-bin/hgTracks?db=neoSch1"
     target=_blank>Jun. 2017 (ASM220157v1/neoSch1)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Hedgehog</td><td>Erinaceus europaeus</td><td>
     May 2012 (EriEur2.0/eriEur2)</td><td><a href="../cgi-bin/hgTracks?db=eriEur2"
     target=_blank>May 2012 (EriEur2.0/eriEur2)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Horse</td><td>Equus caballus</td><td>
     Jan. 2018 (EquCab3.0/equCab3)</td><td><a href="../cgi-bin/hgTracks?db=equCab3"
     target=_blank>Jan. 2018 (EquCab3.0/equCab3)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Human</td><td>Homo sapiens</td><td>
     Dec. 2013 (GRCh38/hg38)</td><td><a href="../cgi-bin/hgTracks?db=hg38"
     target=_blank>Dec. 2013 (GRCh38/hg38)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Lamprey</td><td>Petromyzon marinus</td><td>
     Dec. 2017 (Pmar_germline 1.0/petMar3)</td><td><a href="../cgi-bin/hgTracks?db=petMar3"
     target=_blank>Dec. 2017 (Pmar_germline 1.0/petMar3)</a></td><td>maf net</td></tr>
 <tr align=left><td>Malayan flying lemur</td><td>Galeopterus variegatus</td><td>
     Jun. 2014 (G_variegatus-3.0.2/galVar1)</td><td><a href="../cgi-bin/hgTracks?db=galVar1"
     target=_blank>Jun. 2014 (G_variegatus-3.0.2/galVar1)</a></td><td>maf net</td></tr>
 <tr align=left><td>Marmoset</td><td>Callithrix jacchus</td><td>
     May 2020 (Callithrix_jacchus_cj1700_1.1/calJac4)</td><td><a href="../cgi-bin/hgTracks?db=calJac4"
     target=_blank>May 2020 (Callithrix_jacchus_cj1700_1.1/calJac4)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Opossum</td><td>Monodelphis domestica</td><td>
     Oct. 2006 (Broad/monDom5)</td><td><a href="../cgi-bin/hgTracks?db=monDom5"
     target=_blank>Oct. 2006 (Broad/monDom5)</a></td><td>maf net</td></tr>
 <tr align=left><td>Pig</td><td>Sus scrofa</td><td>
     Aug. 2011 (SGSC Sscrofa10.2/susScr3)</td><td><a href="../cgi-bin/hgTracks?db=susScr3"
     target=_blank>Aug. 2011 (SGSC Sscrofa10.2/susScr3)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Pika</td><td>Ochotona princeps</td><td>
     May 2012 (OchPri3.0/ochPri3)</td><td><a href="../cgi-bin/hgTracks?db=ochPri3"
     target=_blank>May 2012 (OchPri3.0/ochPri3)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Rabbit</td><td>Oryctolagus cuniculus</td><td>
     Apr. 2009 (Broad/oryCun2)</td><td><a href="../cgi-bin/hgTracks?db=oryCun2"
     target=_blank>Apr. 2009 (Broad/oryCun2)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Rat</td><td>Rattus norvegicus</td><td>
     Jul. 2014 (RGSC 6.0/rn6)</td><td><a href="../cgi-bin/hgTracks?db=rn6"
     target=_blank>Jul. 2014 (RGSC 6.0/rn6)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Rhesus</td><td>Macaca mulatta</td><td>
     Feb. 2019 (Mmul_10/rheMac10)</td><td><a href="../cgi-bin/hgTracks?db=rheMac10"
     target=_blank>Feb. 2019 (Mmul_10/rheMac10)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Sheep</td><td>Ovis aries</td><td>
     Nov. 2015 (Oar_v4.0/oviAri4)</td><td><a href="../cgi-bin/hgTracks?db=oviAri4"
     target=_blank>Nov. 2015 (Oar_v4.0/oviAri4)</a></td><td>syntenic net</td></tr>
 <tr align=left><td>Shrew</td><td>Sorex araneus</td><td>
     Aug. 2008 (Broad/sorAra2)</td><td><a href="../cgi-bin/hgTracks?db=sorAra2"
     target=_blank>Aug. 2008 (Broad/sorAra2)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Squirrel</td><td>Spermophilus tridecemlineatus</td><td>
     Nov. 2011 (Broad/speTri2)</td><td><a href="../cgi-bin/hgTracks?db=speTri2"
     target=_blank>Nov. 2011 (Broad/speTri2)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Tarsier</td><td>Tarsius syrichta</td><td>
     Sep. 2013 (Tarsius_syrichta-2.0.1/tarSyr2)</td><td><a href="../cgi-bin/hgTracks?db=tarSyr2"
     target=_blank>Sep. 2013 (Tarsius_syrichta-2.0.1/tarSyr2)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Tenrec</td><td>Echinops telfairi</td><td>
     Nov. 2012 (Broad/echTel2)</td><td><a href="../cgi-bin/hgTracks?db=echTel2"
     target=_blank>Nov. 2012 (Broad/echTel2)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>Tree shrew</td><td>Tupaia belangeri</td><td>
     Dec. 2006 (Broad/tupBel1)</td><td><a href="../cgi-bin/hgTracks?db=tupBel1"
     target=_blank>Dec. 2006 (Broad/tupBel1)</a></td><td>reciprocal best</td></tr>
 <tr align=left><td>X. tropicalis</td><td>Xenopus tropicalis</td><td>
     Jul. 2016 (Xenopus_tropicalis_v9.1/xenTro9)</td><td><a href="../cgi-bin/hgTracks?db=xenTro9"
     target=_blank>Jul. 2016 (Xenopus_tropicalis_v9.1/xenTro9)</a></td><td>maf net</td></tr>
 <tr align=left><td>Zebrafish</td><td>Danio rerio</td><td>
     May 2017 (GRCz11/danRer11)</td><td><a href="../cgi-bin/hgTracks?db=danRer11"
     target=_blank>May 2017 (GRCz11/danRer11)</a></td><td>maf net</td></tr>
   </table>
   <BR>
 <B>Table 1.</B> <EM>Genome assemblies included in the 35-way Conservation 
 track.</EM>
 <BR>* Data download only, browser not available.
 </BLOCKQUOTE>
 
 <H2>Display Conventions and Configuration</H2>
 <P>
 The track configuration options allow the user to display either
 the vertebrate or placental mammal conservation scores, or both
 simultaneously.
 In full and pack display modes, conservation scores are displayed as a
 <EM>wiggle track</EM> (histogram) in which the height reflects the 
 size of the score. 
 The conservation wiggles can be configured in a variety of ways to 
 highlight different aspects of the displayed information. 
 Click the <A HREF="../goldenPath/help/hgWiggleTrackHelp.html" 
 TARGET=_blank>Graph configuration help</A> link for an explanation 
 of the configuration options.</P>
 <P>
 Pairwise alignments of each species to the $organism genome are 
 displayed below the conservation histogram as a grayscale density plot (in 
 pack mode) or as a wiggle (in full mode) that indicates alignment quality.
 In dense display mode, conservation is shown in grayscale using
 darker values to indicate higher levels of overall conservation 
 as scored by phastCons. </P>
 <P>
 Checkboxes on the track configuration page allow selection of the
 species to include in the pairwise display.  
+The names of selected species are colored according to their clade,
+alternating between blue and green.
 Note that excluding species from the pairwise display does not alter the
 the conservation score display.</P>
 <P>
 To view detailed information about the alignments at a specific
 position, zoom the display in to 30,000 or fewer bases, then click on
 the alignment.</P>
 
 <H3>Gap Annotation</H3>
 <P>
 The <EM>Display chains between alignments</EM> configuration option 
 enables display of gaps between alignment blocks in the pairwise alignments in 
 a manner similar to the Chain track display.  The following
 conventions are used:
 <UL>
 <LI><B>Single line:</B> No bases in the aligned species. Possibly due to a
 lineage-specific insertion between the aligned blocks in the $organism genome
 or a lineage-specific deletion between the aligned blocks in the aligning
 species.
 <LI><B>Double line:</B> Aligning species has one or more unalignable bases in
 the gap region. Possibly due to excessive evolutionary distance between 
 species or independent indels in the region between the aligned blocks in both
 species. 
 <LI><B>Pale yellow coloring:</B> Aligning species has Ns in the gap region.
 Reflects uncertainty in the relationship between the DNA of both species, due
 to lack of sequence in relevant portions of the aligning species. 
 </UL></P>
 
 <H3>Genomic Breaks</H3>
 <P>
 Discontinuities in the genomic context (chromosome, scaffold or region) of the
 aligned DNA in the aligning species are shown as follows: 
 <UL>
 <LI>
 <B>Vertical blue bar:</B> Represents a discontinuity that persists indefinitely
 on either side, <em>e.g.</em> a large region of DNA on either side of the bar
 comes from a different chromosome in the aligned species due to a large scale
 rearrangement. 
 <LI>
 <B>Green square brackets:</B> Enclose shorter alignments consisting of DNA from
 one genomic context in the aligned species nested inside a larger chain of
 alignments from a different genomic context. The alignment within the
 brackets may represent a short misalignment, a lineage-specific insertion of a
 transposon in the $organism genome that aligns to a paralogous copy somewhere
 else in the aligned species, or other similar occurrence.
 </UL></P>
 
 <H3>Base Level</H3>
 <P>
 When zoomed-in to the base-level display, the track shows the base 
 composition of each alignment. 
 The numbers and symbols on the Gaps
 line indicate the lengths of gaps in the $organism sequence at those 
 alignment positions relative to the longest non-$organism sequence. 
 If there is sufficient space in the display, the size of the gap is shown. 
 If the space is insufficient and the gap size is a multiple of 3, a 
 &quot;*&quot; is displayed; other gap sizes are indicated by &quot;+&quot;.</P>
 <P>
 Codon translation is available in base-level display mode if the
 displayed region is identified as a coding segment. To display this annotation,
 select the species for translation from the pull-down menu in the Codon
 Translation configuration section at the top of the page. Then, select one of
 the following modes:
 <UL>
 <LI> 
 <B>No codon translation:</B> The gene annotation is not used; the bases are
 displayed without translation. 
 <LI>
 <B>Use default species reading frames for translation:</B> The annotations from the genome
 displayed 
 in the <EM>Default species to establish reading frame</EM> pull-down menu are used to
 translate all the aligned species present in the alignment. 
 <LI>
 <B>Use reading frames for species if available, otherwise no translation:</B> Codon
 translation is performed only for those species where the region is
 annotated as protein coding.
 <LI><B>Use reading frames for species if available, otherwise use default species:</B>
 Codon translation is done on those species that are annotated as being protein
 coding over the aligned region using species-specific annotation; the remaining
 species are translated using the default species annotation. 
 </UL></P>
 <P>
 Codon translation uses the following gene tracks as the basis for
 translation, depending on the species chosen (<B>Table 2</B>).  
 
 <BLOCKQUOTE><TABLE CELLPADDING=4 class="descTbl">
 <TR ALIGN=left><TD><B>Gene Track</B></TD><TD><B>Species</B></TD></TR>
 <TR ALIGN=left><TD>Known Genes</TD><TD>human</TD></TR>
 <TR ALIGN=left><TD>Ensembl Genes</TD><TD>tree shrew, opossum</TD></TR>
 <TR ALIGN=left><TD>NCBI RefSeq</TD><TD>beaver, bonobo, bushbaby, chicken, Chinese hamster, chimp, cow, elephant, gorilla, guinea pig, hawaiian monk seal, hedgehog, horse, malayan flying lemur, marmoset, mouse, pig, pika, rabbit, rat, rhesus, sheep, shrew, squirrel, tarsier, tenrec, X. tropicalis, zebrafish</TD></TR>
 <TR ALIGN=left><TD>Xeno RefGene</TD><TD>Chinese pangolin, dog, dolphin, lamprey</TD></TR>
 </TABLE>
 <B>Table 2.</B> <EM>Gene tracks used for codon translation.</EM>
 </BLOCKQUOTE></P>
 
 <H2>Methods</H2>
 <P> 
 Pairwise alignments with the mouse genome were generated for 
 each species using lastz from repeat-masked genomic sequence. 
 Pairwise alignments were then linked into chains using a dynamic programming
 algorithm that finds maximally scoring chains of gapless subsections
 of the alignments organized in a kd-tree.
 The scoring matrix and parameters for pairwise alignment and chaining
 were tuned for each species based on phylogenetic distance from the reference.
 High-scoring chains were then placed along the genome, with
 gaps filled by lower-scoring chains, to produce an alignment net.
 For more information about the chaining and netting process and 
 parameters for each species, see the description pages for the Chain and Net 
 tracks.</P>
 <P>
 An additional filtering step was introduced in the generation of the 35-way
 conservation track to reduce the number of paralogs and pseudogenes from the 
 high-quality assemblies and the suspect alignments from the low-quality 
 assemblies:
 the pairwise alignments of high-quality mammalian 
 sequences (placental and marsupial) were filtered based on synteny; 
 those for 2X mammalian genomes were filtered to retain only 
 alignments of best quality in both the target and query (&quot;reciprocal 
 best&quot;).</P>
 <P>
 The resulting best-in-genome pairwise alignments
 were progressively aligned using multiz/autoMZ, 
 following the tree topology diagrammed above, to produce multiple alignments.
 The multiple alignments were post-processed to
 add annotations indicating alignment gaps, genomic breaks,
 and base quality of the component sequences.
 The annotated multiple alignments, in MAF format, are available for
 <A HREF="http://hgdownload.soe.ucsc.edu/goldenPath/mm39/multiz35way"
 TARGET=_blank>bulk download</A>.
 An alignment summary table containing an entry for each
 alignment block in each species was generated to improve
 track display performance at large scales.
 Framing tables were constructed to enable
 visualization of codons in the multiple alignment display.</P>
 <P>
 Conservation scoring was performed using the PhastCons package (A. Siepel),
 which computes conservation based on a two-state phylogenetic hidden Markov
 model (HMM).
 PhastCons measurements rely on a tree model containing the tree topology,
 branch lengths representing evolutionary distance at neutrally
 evolving sites, the background distribution of nucleotides, and a substitution
 rate matrix.  The 
 <A HREF="http://hgdownload.soe.ucsc.edu/goldenPath/mm39/phastCons35way/mm39.phastCons35way.mod"
 TARGET=_blank>vertebrate tree model</A> for this track was
 generated using the phyloFit program from the phastCons package  
 (REV model, EM algorithm, medium precision) using multiple alignments of 
 4-fold degenerate sites extracted from the 28-way human(hg18) alignment
 (msa_view).  The 4d sites were derived from the 
 <A HREF="https://www.sanger.ac.uk/science/tools" TARGET=_blank>Oct 2005 Gencode 
 Reference Gene set</A>,
 which was filtered to select single-coverage long transcripts.
 The phastCons parameters used for the conservation measurement
 were: expected-length=45, target-coverage=.3 and rho=.31</P>
 <P>
 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.  Unlike many conservation-scoring programs, 
 note that phastCons does not rely on a sliding window
 of fixed size; therefore, short highly-conserved regions and long moderately
 conserved regions can both obtain high scores.  More information about
 phastCons can be found in Siepel <EM>et al</EM>. 2005.</P> 
 <P> 
 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.</P>
 
 <h2>Data Access</h2>
 You can access this data in the <a 
 href="hgTables?db=mm39&hgta_group=compGeno&hgta_track=cons35way">
 Table Browser</a> for position or identifier based queries in multiple formats.
 Downloads for data in this track are available in the following locations:
 <UL>
 <LI>
 <A HREF="http://hgdownload.soe.ucsc.edu/goldenPath/mm39/multiz35way/">Multiz alignments</A> 
 (MAF format), and phylogenetic trees <LI>
 <A HREF="http://hgdownload.soe.ucsc.edu/goldenPath/mm39/phyloP35way/">PhyloP conservation</A> 
 (WIG format)
 <LI>
 <A HREF="http://hgdownload.soe.ucsc.edu/goldenPath/mm39/phastCons35way/">PhastCons conservation</A> 
 (WIG format)
 </UL>
 
 
 <H2>Credits</H2>
 <P> This track was created using the following programs:
 <UL>
 <LI> Alignment tools: lastz (formerly blastz) and multiz by Minmei Hou, Scott Schwartz and Webb 
 Miller of the <A HREF="http://www.bx.psu.edu/miller_lab/" 
 TARGET=_blank>Penn State Bioinformatics Group</A>
 <LI> Chaining and Netting:  axtChain, chainNet by Jim Kent at UCSC
 <LI> Conservation scoring: PhastCons, phyloFit, tree_doctor, msa_view by 
 <A HREF="https://siepellab.labsites.cshl.edu/"
 TARGET=_blank>Adam Siepel</A> while at UCSC, now at Cold Spring Harbor Laboratory
 <LI> MAF Annotation tools: mafAddIRows by Brian Raney, UCSC; mafAddQRows
 by Richard Burhans, Penn State; genePredToMafFrames by Mark Diekhans, UCSC
 <LI> Tree image generator: phyloPng by Galt Barber, UCSC
 <LI> Conservation track display: Kate Rosenbloom, Hiram Clawson (wiggle 
 display), and Brian Raney (gap annotation and codon framing) at UCSC
 </UL>
 </P>
 <P>The phylogenetic tree is based on Murphy <EM>et al</EM>. (2001) and general 
 consensus in the vertebrate phylogeny community as of March 2007.
 </P>
 
 <H2>References</H2>
 
 <H3>Phylo-HMMs and phastCons:</H3>
 <P>
 Felsenstein J, Churchill GA.
 <A HREF="https://academic.oup.com/mbe/article/13/1/93/1055515"
 TARGET=_blank>A Hidden Markov Model approach to
 variation among sites in rate of evolution</A>.
 <em>Mol Biol Evol</em>. 1996 Jan;13(1):93-104.
 PMID: <a href="https://www.ncbi.nlm.nih.gov/pubmed/8583911" target="_blank">8583911</a>
 </p>
 
 <P>
 Siepel A, Haussler D.
 <A HREF="http://compgen.cshl.edu/~acs/phylohmm.pdf"
 TARGET=_blank>Phylogenetic Hidden Markov Models</A>.
 In: Nielsen R, editor. Statistical Methods in Molecular Evolution.
 New York: Springer; 2005. pp. 325-351.
 </P>
 
 <P>
 Siepel A, Bejerano G, Pedersen JS, Hinrichs AS, Hou M, Rosenbloom K,
 Clawson H, Spieth J, Hillier LW, Richards S, <EM>et al.</EM>
 <A HREF="https://genome.cshlp.org/content/15/8/1034"
 TARGET=_blank>Evolutionarily conserved elements in vertebrate, insect, worm,
 and yeast genomes</A>.
 <em>Genome Res</em>. 2005 Aug;15(8):1034-50.
 PMID: <a href="https://www.ncbi.nlm.nih.gov/pubmed/16024819" target="_blank">16024819</a>; PMC: <a
 href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1182216" target="_blank">PMC1182216</a>
 </p>
 
 <P>
 Yang Z.
 <A HREF="https://www.genetics.org/content/139/2/993"
 TARGET=_blank>A space-time process model for the evolution of DNA
 sequences</A>.
 <em>Genetics</em>. 1995 Feb;139(2):993-1005.
 PMID: <a href="https://www.ncbi.nlm.nih.gov/pubmed/7713447" target="_blank">7713447</a>; PMC: <a
 href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1206396" target="_blank">PMC1206396</a>
 </p>
 
 <H3>Chain/Net:</H3>
 <P>
 Kent WJ, Baertsch R, Hinrichs A, Miller W, Haussler D.
 <A HREF="https://www.pnas.org/content/100/20/11484"
 TARGET=_blank>Evolution's cauldron:
 duplication, deletion, and rearrangement in the mouse and human genomes</A>.
 <em>Proc Natl Acad Sci U S A</em>. 2003 Sep 30;100(20):11484-9.
 PMID: <a href="https://www.ncbi.nlm.nih.gov/pubmed/14500911" target="_blank">14500911</a>; PMC: <a
 href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC208784" target="_blank">PMC208784</a>
 </p>
 
 <H3>Multiz:</H3>
 <P>
 Blanchette M, Kent WJ, Riemer C, Elnitski L, Smit AF, Roskin KM,
 Baertsch R, Rosenbloom K, Clawson H, Green ED, <EM>et al.</EM>
 <A HREF="https://genome.cshlp.org/content/14/4/708.abstract"
 TARGET=_blank>Aligning multiple genomic sequences with the threaded blockset aligner</A>.
 <em>Genome Res</em>. 2004 Apr;14(4):708-15.
 PMID: <a href="https://www.ncbi.nlm.nih.gov/pubmed/15060014" target="_blank">15060014</a>; PMC: <a
 href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC383317" target="_blank">PMC383317</a>
 </p>
 
 <H3>Lastz (formerly Blastz):</H3>
 <P>
 Chiaromonte F, Yap VB, Miller W.
 <A HREF="http://psb.stanford.edu/psb-online/proceedings/psb02/chiaromonte.pdf"
 TARGET=_blank>Scoring pairwise genomic sequence alignments</A>.
 <em>Pac Symp Biocomput</em>. 2002:115-26.
 PMID: <a href="https://www.ncbi.nlm.nih.gov/pubmed/11928468" target="_blank">11928468</a>
 </p>
 
 <p>
 Harris RS.
 <a href="http://www.bx.psu.edu/~rsharris/rsharris_phd_thesis_2007.pdf"
 target="_blank">Improved pairwise alignment of genomic DNA</a>.
 <em>Ph.D. Thesis</em>. Pennsylvania State University, USA. 2007.
 </p>
 
 <P>
 Schwartz S, Kent WJ, Smit A, Zhang Z, Baertsch R, Hardison RC,
 Haussler D, Miller W.
 <A HREF="https://genome.cshlp.org/content/13/1/103.abstract"
 TARGET=_blank>Human-mouse alignments with BLASTZ</A>.
 <em>Genome Res</em>. 2003 Jan;13(1):103-7.
 PMID: <a href="https://www.ncbi.nlm.nih.gov/pubmed/12529312" target="_blank">12529312</a>; PMC: <a
 href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC430961" target="_blank">PMC430961</a>
 </p>
 
 <H3>Phylogenetic Tree:</H3>
 <P>
 Murphy WJ, Eizirik E, O'Brien SJ, Madsen O, Scally M, Douady CJ, Teeling E,
 Ryder OA, Stanhope MJ, de Jong WW, Springer MS.
 <A HREF="https://science.sciencemag.org/content/294/5550/2348"
 TARGET=_blank>Resolution of the early placental mammal radiation using Bayesian phylogenetics</A>.
 <em>Science</em>. 2001 Dec 14;294(5550):2348-51.
 PMID: <a href="https://www.ncbi.nlm.nih.gov/pubmed/11743200" target="_blank">11743200</a>
 </p>