SUCROSE CONSUMPTION IN MICE - MAJOR INFLUENCE OF 2 GENETIC-LOCI AFFECTING PERIPHERAL SENSORY RESPONSES

Individual variability in sucrose consumption is prominent in humans a nd other species. To investigate the genetic contribution to this comp lex behavior, we conducted behavioral, electrophysiological, and genet ic studies, using male progeny of two inbred mouse strains (C57BL/6ByJ [B6] and 129/J [129]) and their F-2 hybrids. Two loci on Chromosome ( Chr)4 were responsible for over 50% of the genetic variability in sucr ose intake. These loci apparently modulated intake by altering periphe ral neural responses to sucrose. One locus affected the response thres hold, whereas the other affected the response magnitude. These finding s suggest that the majority of difference in sucrose intake between ma le B6 and 129 mice is due to polymorphisms of two genes that influence receptor or peripheral nervous system activity.