Genetic component of sensorimotor capacity in rats

Abstract

Creation of generalized genetic models for low and high sensorimotor capacity would be important tools for resolution of this complex trait. As proof-of-principle we estimated phenotypic variation and narrow-sense heritability (h2) of sensorimotor capacity in 19 families of genetically heterogeneous N:NIH rats and in 11 strains of inbred rats. Sensorimotor capacity was defined as the time a rat remained on an accelerating rotorod. N:NIH rats recorded variation in rotorod scores that ranged from 3- to 7-fold. The value of h2, estimated from offspring-parent regression across one generation, was 0.68 for females and 0.74 for males in N:NIH rats. In inbred rats, h2 was estimated by partitioning phenotypic variation into additive genetic and environmental components and averaged 0.39 in females and 0.48 in males. These results demonstrate a heritable component to sensorimotor capacity sufficient for success in developing contrasting genetic models by divergent artificial selection in rats.