Mapping an overdominant quantitative trait locus for heterosis of body weight in mice.
The genetic basis of heterosis has not been elucidated. Previously, a congenic mouse strain with a 44-Mb genomic region of proximal chromosome 2 containing the allele derived from wild Mus musculus castaneus at Pbwg1, a quantitative trait locus (QTL) for body weight and growth, has been developed. In this study, to fine-map and characterize body weight QTLs on the congenic region, QTL analysis of body weight at 1, 3, 6, and 10 weeks after birth was performed on a population of 265 F(2) intercross mice between the developed congenic strain and its background strain C57BL/6J. A significant QTL (named Pbwg1.10) affecting body weight at 6 and 10 weeks of age was identified within an approximately 21-Mb support interval. Surprisingly, Pbwg1.10 had an overdominance effect and caused heterosis for body weight. This result supported the overdominance hypothesis explaining heterosis.
Ishikawa
Akira
A
Laboratory of Animal Genetics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, Japan. ishikawa@agr.nagoya-u.ac.jp
D000818:Animals; D001835:Body Weight / Q000235:genetics*; D002874:Chromosome Mapping / Q000379:methods*; D003433:Crosses, Genetic; D005260:Female; D005799:Genes, Dominant / Q000235:genetics*; D006823:Hybrid Vigor; D008297:Male; D051379:Mice; D040641:Quantitative Trait Loci