This directory contains alignments of the following assemblies:
- target/reference: Chicken
(galGal6, Mar. 2018 (GRCg6a/galGal6),
Genome Reference Consortium)
- query: Burmese python
(pytBiv1, Sep. 2013 (Python_molurus_bivittatus-5.0.2/pytBiv1),
The Consortium for Comparative Genomics, UC Denver GCA_000186305.2)
Files included in this directory:
- md5sum.txt: md5sum checksums for the files in this directory
- galGal6.pytBiv1.all.chain.gz: chained lastz alignments. The chain format is
described in http://genome.ucsc.edu/goldenPath/help/chain.html .
- galGal6.pytBiv1.net.gz: "net" file that describes rearrangements between
the species and the best Burmese python match to any part of the
Chicken genome. The net format is described in
http://genome.ucsc.edu/goldenPath/help/net.html .
- galGal6.pytBiv1.net.axt.gz: chained and netted alignments,
i.e. the best chains in the Chicken 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 .
- galGal6.pytBiv1.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
- galGal6.pytBiv1.syn.net.gz - filtered net file for syntenic alignments only
- reciprocalBest/ directory, contains reciprocal-best netted chains
for galGal6-pytBiv1
The galGal6 and pytBiv1 assemblies were aligned by the lastz alignment
program, which is available from Webb Miller's lab at Penn State
University (http://www.bx.psu.edu/miller_lab/). Any galGal6 sequences larger
than 20,010,000 bases were split into chunks of 20,010,000 bases overlapping
by 10,000 bases for alignment. A similar process was followed for pytBiv1,
with chunks of 1,000,000 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 lastz 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=4000 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:
M=254
Y=3400
The .lav format lastz output was translated to the .psl format with
lavToPsl, then chained by the axtChain program.
Chain minimum score: 1000, 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 lastz 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.soe.ucsc.edu, then go to the directory
goldenPath/galGal6/vsPytBiv1/. 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 -
galGal6.pytBiv1.all.chain.gz 2018-10-21 07:23 88M
galGal6.pytBiv1.net.axt.gz 2018-10-21 07:26 121M
galGal6.pytBiv1.net.gz 2018-10-21 07:29 30M
galGal6.pytBiv1.syn.net.gz 2018-10-21 07:35 11M
galGal6.pytBiv1.synNet.maf.gz 2018-10-21 07:37 53M
md5sum.txt 2018-10-21 07:37 306
reciprocalBest/ 2018-10-21 12:04 -