SRcompare.pl reads from the standard input and writes to the standard
output. It is meant to compare the set of cofactors in two SRmapqtl
output files. It will print out the number of cofactors that are
the same, lost or gained in the two files.
This option requires an input filename that must exist. It allows the user to specify
the old SRmapqtl.out file for processing. If it is not given, then the script dies.
The input files should be of the same format as the output of SRmapqtl.
You should have only one set of such results in a file to be processed by
SRcompare.pl. These results are created by Eqtl as well as SRmapqtl.
Suppose we have a map in qtlcart.map and a data file in qtlcart.cro, and
that there is no resource file in the current directory. For this example,
assume that there are only two marker genotypes (that is a backcross or recombinant
inbred line) and one trait. The following series of commands can be used to
compare the cofactors chosen from interval mapping with those from composite interval
mapping:
% Qstats -X qtlcart
% Zmapqtl -M 3 -A
% Eqtl -S 12.0 -H 10 -I Z -A
% mv qtlcart.z qtlcart.z.1
% Zmapqtl -M 8 -A
% mv qtlcart.eqt qtlcart.eqt.1
% mv qtlcart.sr qtlcart.sr.1
% Eqtl -S 12.0 -H 10 -I Z -A
% SRcompare.pl -f qtlcart.sr.1 < qtlcart.sr
In the above, Qstats is run to set the filename stem. Next, Zmapqtl does an
interval mapping analysis and Eqtl picks a set of markers closest to the peaks
from interval mapping: These peaks are only used if they have likelihood ratios greater
than 12.0. Next, the interval mapping results are moved to an new file and
composite interval mapping is run using the cofactors identified via interval mapping.
The previous output files of Eqtl (qtlcart.eqt and qtlcart.sr) are renamed and
new files are generated from the composite interval mapping results. Then, SRcompare.pl
is used to compare the two sets of results, those from interval mapping (qtlcart.sr.1)
and those from composite interval mapping (qtlcart.sr).
This type of analysis can be iterated until a stable set of cofactors are identified.
Christopher J. Basten, B. S. Weir and Z.-B. Zeng
Department of Statistics, North Carolina State University
Raleigh, NC 27695-7566, USA
Phone: (919)515-1934