This directory contains alignments of the following assemblies:
- target/reference: Human
(hg38, Dec. 2013 (GRCh38/hg38),
GRCh38 Genome Reference Consortium Human Reference 38 (GCA_000001405.15))
- query: African clawed frog
(xenLae2, Aug. 2016 (Xenopus_laevis_v2/xenLae2),
International Xenopus Sequencing Consortium)
Files included in this directory:
- md5sum.txt: md5sum checksums for the files in this directory
- hg38.xenLae2.all.chain.gz: chained blastz alignments. The chain format is
described in http://genome.ucsc.edu/goldenPath/help/chain.html .
- hg38.xenLae2.net.gz: "net" file that describes rearrangements between
the species and the best African clawed frog match to any part of the
Human genome. The net format is described in
http://genome.ucsc.edu/goldenPath/help/net.html .
- hg38.xenLae2.net.axt.gz: chained and netted alignments,
i.e. the best chains in the Human genome, with gaps in the best
chains filled in by next-best chains where possible. The axt format is
described in http://genome.ucsc.edu/goldenPath/help/axt.html .
- hg38.xenLae2.synNet.maf.gz - filtered net file for syntenic alignments
only, in MAF format, see also, description of MAF format:
http://genome.ucsc.edu/FAQ/FAQformat.html#format5
- hg38.xenLae2.syn.net.gz - filtered net file for syntenic alignments only
- reciprocalBest/ directory, contains reciprocal-best netted chains
for hg38-xenLae2
The hg38 and xenLae2 assemblies were aligned by the blastz alignment
program, which is available from Webb Miller's lab at Penn State
University (http://www.bx.psu.edu/miller_lab/). Any hg38 sequences larger
than 40,010,000 bases were split into chunks of 40,010,000 bases overlapping
by 10,000 bases for alignment. A similar process was followed for xenLae2,
with chunks of 20,000,000 overlapping by 0. Following alignment, the
coordinates of the chunk alignments were corrected by the
blastz-normalizeLav script written by Scott Schwartz of Penn State.
The blastz scoring matrix (Q parameter) used was:
A C G T
A 91 -90 -25 -100
C -90 100 -100 -25
G -25 -100 100 -90
T -100 -25 -90 91
with a gap open penalty of O=400 and a gap extension penalty of E=30.
The minimum score for an alignment to be kept was K=2200 for the first pass
and L=6000 for the second pass, which restricted the search space to the
regions between two alignments found in the first pass. The minimum
score for alignments to be interpolated between was H=2000. Other blastz
parameters specifically set for this species pair:
E=30
M=50
O=400
Y=3400
The .lav format blastz output was translated to the .psl format with
lavToPsl, then chained by the axtChain program.
Chain minimum score: 5000, and linearGap matrix of (loose):
tablesize 11
smallSize 111
position 1 2 3 11 111 2111 12111 32111 72111 152111 252111
qGap 325 360 400 450 600 1100 3600 7600 15600 31600 56600
tGap 325 360 400 450 600 1100 3600 7600 15600 31600 56600
bothGap 625 660 700 750 900 1400 4000 8000 16000 32000 57000
Chained alignments were processed into nets by the chainNet, netSyntenic,
and netClass programs.
Best-chain alignments in axt format were extracted by the netToAxt program.
All programs run after blastz were written by Jim Kent at UCSC.
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If you plan to download a large file or multiple files from this directory,
we recommend you use ftp rather than downloading the files via our website.
To do so, ftp to hgdownload.cse.ucsc.edu, then go to the directory
goldenPath/hg38/vsXenLae2/. To download multiple files, use the "mget"
command:
mget <filename1> <filename2> ...
- or -
mget -a (to download all files in the current directory)
All files in this directory are freely available for public use.
--------------------------------------------------------------------
References
Chiaromonte F, Yap VB, Miller W. Scoring pairwise genomic sequence
alignments. Pac Symp Biocomput. 2002:115-26.
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.
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.
Name Last modified Size Description
Parent Directory -
hg38.xenLae2.all.chain.gz 2017-03-30 07:54 146M
hg38.xenLae2.net.axt.gz 2017-03-30 08:11 65M
hg38.xenLae2.synNet.maf.gz 2017-03-30 08:27 26M
hg38.xenLae2.net.gz 2017-03-30 08:18 17M
hg38.xenLae2.syn.net.gz 2017-03-30 08:26 5.7M
md5sum.txt 2017-03-30 08:27 291
reciprocalBest/ 2017-03-30 20:26 -