Single-gene Effects on Body Weight in Selected and Unselected Mouse Lines Detected by Bayesian Marker-free Segregation Analysis

Abstract

Segregation analysis of body weight at 21, 42, and 63 days in eleven generations of unselected (2813 individuals  of C line) and selected (1410 individuals of HGC line, derived from C line) mice was performed.  The Gibbs sampling algorithm was applied to obtain posterior density distributions of model parameters.  Moderate heritability via polygenic model was estimated. The results suggest a mixed inheritance model  (major gene + polygenic) for the body weight. The proportion of single gene variance to phenotypic variance  ranged from 9.7 to 41 percent. The estimated additive heritabilities for these traits varied between 0.25  and 0.47 for the C line and 0.37 and 0.41 for the HGC line. Considerable differences in estimated major  gene frequencies were found between unselected and selected lines.