[Polygenic correlates of characteristics of the rhythm of activity in mammals: study of 2 inbred C57BL/6 and BALB/cBy mouse strains].

Rhythm of activity in inbred strains of mice in synchronic LD 12:12 was shown to be characterized by six indices: amount of activity, circadian level, pulsatile activity, ratio of nocturnal/diurnal activity, and two temporal frequency descriptors. Genetic analysis of rhythm of activity was conducted on parental strains C57BL/6By and BALB/cBy via the reciprocal F1s and the seven recombinant inbred lines. No maternal effect for the reciprocal F1s was observed. The findings indicate dominance and heterosis effects for the F1s. Heterosis tends towards a better fit of rhythm to natural day/night synchrony. RI findings eliminate the hypothesis of monogenetic correlates for all six parameters investigated, and in conjunction with the F1 analysis demonstrate that each indices have polygenic correlates with at least one different locus for each of the measures of activity.