64f5e1fb8b93253cf89a6f36fb00d67d2ededf1d
gperez2
  Sun Mar 15 20:52:02 2026 -0700
Updating the QuickLift documentation page and the Alignment Differences page, refs #35536

diff --git src/hg/htdocs/goldenPath/help/quickLiftChain.html src/hg/htdocs/goldenPath/help/quickLiftChain.html
index f36c45f7f36..c3ffb71fa35 100644
--- src/hg/htdocs/goldenPath/help/quickLiftChain.html
+++ src/hg/htdocs/goldenPath/help/quickLiftChain.html
@@ -1,73 +1,98 @@
 <h2>Description</h2>
 <p>
-The Alignment Differences track shows mismatches and indels between the assembly from which the
-track was QuickLifted and the current genome.
+The Alignment Differences track shows mismatches, insertions, deletions, and double-sided
+insertions between two assemblies. In <font color="#008000">QuickLift</font>, the
+<b>source assembly</b> is the assembly where the annotations come from, and the
+<b>destination (target) assembly</b> is the assembly you are currently viewing.
+<font color="#008000">QuickLift</font> maps (liftOver) annotations on demand from the source
+to the target using whole-genome alignment chains.
 </p>
 
 <h2>Display Conventions and Configuration</h2>
 <p>
-Visible tracks, custom tracks, and track hubs on the Browser graphic page are carried over (lifted)
-to the new assembly using the <font color="#008000">QuickLift</font> tracks checkbox. When a single
-track from a container track, such as a superTrack or composite, is lifted, the entire container
-track is carried over to the new assembly.
+This track is part of the <font color="#008000">QuickLift</font> track group, which appears
+under a green &quot;<font color="#008000">QuickLift</font> from ...&quot; group in the target
+genome assembly. <font color="#008000">QuickLift</font> tracks have a green left-side button
+bar in the Browser graphic, instead of the usual gray, and can be removed by the
+<button>Disconnect</button> button.
 </p>
 <p>
-<font color="#008000">QuickLift</font> tracks appear under a green
-&quot;<font color="#008000">QuickLift</font> from ...&quot; group in the New assembly.
-<font color="#008000">QuickLift</font> tracks can be removed by the 
-<button>Disconnect</button> button. <font color="#008000">QuickLift</font> tracks have a green
-left-side button bar in the Browser graphic, instead of the usual gray.
-</p>
-<p>
-The &quot;Alignment Differences&quot; track displays liftOver differences using triangles and
-lines; mousing over a triangle displays base-pair (bp) information. Lines and triangles are
-color-coded as follows:
+The Alignment Differences track displays liftOver differences using triangles and
+lines. Alignment differences are marked by lines, with colored triangles indicating the type of
+difference:
 </p>
 <ul>
   <li>Insertions:
   <font color="#407F00">green</font></li>
 
   <li>Deletions:
   <font color="#00007F">blue</font></li>
 
   <li>Double-sided insertions:
-  <font color="#7F7F7F">gray</font></li>
+  <font color="#7F7F7F">gray</font> (Both the source and target assemblies contain
+  unalignable sequence between two regions of aligned sequence)</li>
 
   <li>Mismatches:
   <font color="#FF0000">red</font></li>
 </ul>
  <div class="text-center">
  <img src="../../images/QuickLift/quickLiftTrianglesMouseOver.png" width='70%'>
  </div>
-<p>Clicking a triangle provides additional information about the alignment.</p>
+<p>
+Mousing over a triangle displays the size base-pair (bp) difference and the type of alignment
+difference. Clicking a triangle opens a details page showing:
+</p>
+<ul>
+  <li>Source and target assembly genome positions</li>
+  <li>DNA sequence alignment</li>
+  <li>Type and size of each alignment difference within the currently visible browser
+  region</li>
+</ul>
+<div class="text-center">
+<img src="../../images/QuickLift/quickLiftAlignmentDifferences.png" width='50%'>
+</div>
 
 <h2>Methods</h2>
 <p>
 An alignment between two DNA sequences maps every nucleotide in one sequence to a nucleotide in
 another sequence. By making and using whole-genome alignments (Kent et al., 2003),
 genome annotations can be &quot;lifted&quot; to another assembly
-(<a href="/cgi-bin/hgLiftOver" target="_blank">LiftOver</a>) in bulk, one track at a time.
-<font color="#008000">QuickLift</font> is a tool that uses the same algorithm, but it maps
-(&quot;liftOver&quot;) annotations on demand, in real-time, for all visible tracks. Only the
-annotations in the currently visible region are lifted, so this is usually fast enough when
-browsing a genome.
+(<a href="/cgi-bin/hgLiftOver" target="_blank">liftOver</a>) in bulk, one track at a time.
+<font color="#008000">QuickLift</font> uses the same algorithm to lift annotations on demand, in
+real-time, for all visible tracks. Only the annotations in the currently visible region are lifted,
+so this is usually fast enough when browsing a genome.
+</p>
+
+<p>
+The Alignment Differences track is generated by comparing the whole-genome alignment chain between
+the source and target assemblies. Where the alignment differs, the track classifies each
+difference by type:
 </p>
+<ul>
+  <li><b>Insertions and Deletions</b> &mdash; gaps in the alignment where one assembly has
+  sequence that the other does not</li>
+  <li><b>Double-sided insertions (double gaps)</b> &mdash; both assemblies contain
+  unalignable sequence between two aligned regions</li>
+  <li><b>Mismatches</b> &mdash; aligned positions where the bases differ between the two
+  assemblies</li>
+</ul>
 
 <p>
 <font color="#008000">QuickLift</font> functionality depends on the availability of alignment files
 (chains) that describe how sequences in one assembly correspond to another. The alignment files are
-currently made at UCSC, but we are working on making the pipeline to align two genomes more widely
-available.
+currently made at UCSC, and if no alignment file is available for the assembly in which you're
+interested, please send a request to the <a href="/contacts.html" target="_blank"
+>genome mailing list</a>, and we will attempt to provide you with one.
 </p>
 
 <h2>References</h2>
 <p>
 Kent WJ, Baertsch R, Hinrichs A, Miller W, Haussler D.
 <a href="https://www.pnas.org/doi/10.1073/pnas.1932072100?url_ver=Z39.88-
 2003&amp;rfr_id=ori:rid:crossref.org&amp;rfr_dat=cr_pub%20%200pubmed" target="_blank">
 Evolution&#x27;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>