PROVISIONAL QUANTITATIVE TRAIT LOCI (QTL) FOR THE ASCHOFF EFFECT IN RI MICE

Mice of the CXB recombinant inbred (RI) panel were phenotyped for peri od of locomotor activity in continuous dark (tau) and in continuous 10 -lux light (tau(LL)). There were significant differences in the effect of light on period, Delta tau (tau(LL)-tau), among CXB RI strains and their progenitors. By comparing strain means for Delta tau in the CXB RI strains with typed genetic loci using a product moment correlation , it was possible to hypothesize quantitative trait ion (QTL) importan t to the genetic variance in the effect of constant low-level light on circadian period. Some of the candidate genes linked to statistically associated markers are neuropharmacologically interesting. Provisiona l QTL for Delta tau were found on proximal Chromosome 8 and mid Chromo some 11 in regions near QTL identified in a similar analysis of the BX D RI panel. This provides additional evidence for the importance of lo ci on Chromosomes 8 and 11. (C) 1998 Elsevier Science Inc.