Early development in mice: V. Sensorimotor development of four coisogenic mutant strains

Effects on sensorimotor development of four genes (at, Re, fz, and Wv) involved in coat color differences were investigated by employing four coisogenic strains of mice with the same genetic background C57BL/6JOrl (B6). Compared to wild-type B6, two mutations (fz and Wv) showed pleiotropic effects on development but the direction of these effects (delay or advance) differed in different tests. Body weight was decreased for each mutation. Heterozygosity vs. homozygosity at the W locus caused differences in crossed extensor, bar holding and female body weight. Epistatic effects between the at and Re genes were investigated by developing a double coisogenic strain, and were found for righting, hindpaw grasping, vibrissae placing responses and weight.