Abstract
This is the first phenotypic analysis of 75 new recombinant inbred (RI) strains derived from ILS and ISS progenitors. We analyzed body weight in two independent cohorts of female mice at various ages and in males at 60 days. Body weight is a complex trait which has been mapped in numerous crosses in rodents. The LXS RI strains displayed a large range of weights, transgressing those of the inbred progenitors, supporting the utility of this large panel for mapping traits not selected in the progenitors.
Numerous QTLs for body weight mapped in singleand
multilocus scans. We assessed replication between
these and previously reported QTLs based on
overlapping confidence intervals of published QTLs
for body weight at 60 days and used meta-analyses to
determine combined p values for three QTL regions
located on Chromosomes 4, 5, and 11. Strain distribution
patterns of microsatellite marker genotypes,
weight, and other phenotypes are available on Web-
QTL (http://www.webqtl.org/search.html) and allow
genetic mapping of any heritable quantitative phenotype
measured in these strains. We report one
such analysis, correlating brain and body weights.
Large reference panels of RI strains, such as the LXS,
are invaluable for identifying genetic correlations,
GXE (Gene X Environment) interactions, and replicating
previously identified QTLs.