GENETIC TRANSMISSION OF NACL AVERSION IN THE FISCHER-344 RAT

Fischer-344 (F-344) rats fail to prefer sodium chloride (NaCl) solutions to water at any concentration, and avoid NaCl solutions preferred by other strains including the Buffalo (BF) rat. These findings implicate a genetic mechanism in the salt aversion of the F-344, and the present study examined patterns of genetic transmission of this behaviour. Two inbred strains, F-344 and BF, were crossed, and the off spring from eight litters were examined. In half the breeding pairs, F-344 was the maternal genotype. Twelve pairs of F1 animals were randomly mated to produce an F2 population. NaC1 preference of F1 and F2 male offspring was examined in 24-h, two-bottle preference tests with water and NaCI solutions. Offspring were classified as 'preferent' or 'avoidant' on the basis of preference test scores, and the proportions of avoidant animals in the F1 and F2 populations were compared to those predicted by three simple genetic models. The observed ratios were not significantly different from those predicted by the single-locus model with NaCl avoidance as a recessive trait. NaCl preference scores of F1 animals did not reveal an effect of maternal genotype on the trait of NaCl avoidance. © 1990 Oxford University Press.