Investigation on presence of major gene for body weight, feed intake and feed efficiency using a segregation analyses in a mice population

Abstract

Recent developments in molecular genetics and statistics have allowed the identification and use of major genes to explain the genetic variation. In this context, segregation analysis is a fast, reliable and inexpensive method that uses only phenotype and pedigree information. The aim of this study was to examine whether body weight, feed intake, and feed efficiency in a mouse population are directed by major gene in addition to polygenic and major gene effects by segregation analysis. For this purpose, previously collected dataset was used (n= 661). In this study, genetic variance, error variance, major gene variance, additive and dominant gene effects were estimated by segregation analyses. Dominant variance (1.04) was found to be smaller than the additive genetic variance (7.32) for body weight. Polygenic and major gene heritability predicted as 0.29 (± 0.63) and 0.81 (± 0.98) for body weight, 0.35 (± 0.63) and 0.96 (± 0.98) for feed intake and 0.52 (± 0.63) and 0.81 (± 0.98) for feed efficiency respectively. Existence of major gene was determined by examining the highest probability density regions. Although the major gene has been identified for body weight and feed intake, this result is not confirmed by the Mendelian transmission probabilities.