A quantitative genetic analysis of slow-wave sleep and rapid-eye movement sleep in CXB recombinant inbred mice

Various inbred strains of mice show different daily amounts of slow-wave sl eep (SWS) and rapid-eye movement sleep (REMS), suggesting the possibility o f genetic influences on sleep propensity. Previous work by others studying the spontaneous sleep patterns of seven strains of CXB recombinant inbred ( RI) mice suggested several candidate quantitative trait loci (QTLs) associa ted with variation in REMS. Extending this approach, we evaluated the sleep patterns of 13 CXB RI strains and conducted linkage analyses based on 223 discrete informative loci. The probability density distribution of light ph ase REMS for the CXB RI strains showed deflections that correspond approxim ately to the parental phenotypes. This type of pattern is consistent with t he presence of a low number of major effect quantitative trait loci. Region s of chromosomes 4, 16, and 17 showed provisional linkage to strain variati on in REMS. The distribution of loci further suggested that dark phase and light phase REMS may be regulated by different genetic factors. Probabiliti es of linkage were not sufficient for declaration of a quantitative trait l ocus for REMS but were sufficient to warrant further analysis either with a dditional RI strains or with F-2 panels.