Physiological function and behavioral genetics. II. Quantitative genetic an analysis of conduction velocity of caudal nerves of the mouse, Mus musculus.

Abstract

Scores for body weight, tail length, and caudal nerve conduction velocity (assessed by direct, in vivo methods) from 1701 mice from the DBA/1J and C3H/HeJ inbred strains and their derived generations were employed for genetic analysis. Substantial strain differences were observed for the three characters, and hybrid scores exceeded those of inbreds. Within the reciprocal backcrosses, mating groups with inbred female parents had lower average scores for the three variables than did groups with hybrid female parents. The nature of this maternal influence is being examined. Heritability estimates from comparison of generation variances were high and not consistent. Those from generation means were lower, consistent, and in close agreement with estimates from regression of F3 offspring on their F2 parent scores. The heritability of conduction velocity in this population is apparently about 0.10. Regression estimates of heritability using 950 animals from an eight-way cross suggest that the heritability of caudal nerve conduction velocity in that population is about 0.20. From both populations, a slight positive genetic correlation among the characters is indicated.