Genetic Analysis of the Corticosterone Response to Ethanol in BXD Recombinant Inbred Mice

The genetic control over the corticosterone response to ethanol (EtOH) and its possible relationship to other EtOH-related traits was examined using BXD recombinant inbred (RI) strains derived from an F2 cross of C57BL/6J (B6) and DBA/2J (D2) progenitor strains. Quantitative trait locus (QTL) analysis of corticosterone levels 1 hr following EtOH suggested the influence of a single major gene on this trait. Two loci were predicted to account for 47% of the genetic variance in plasma corticosterone levels 6 hr following EtOH, whereas 3 loci were predicted to account for 78% of the genetic variance in corticosterone levels 7 hr following EtOH. Markers associated with corticosterone levels 7 hr following EtOH and corrected corticosterone levels 6 hr post-EtOH overlapped with ones found to influence acute and chronic EtOH withdrawal severity, suggesting some degree of common genetic determination between these traits. Overall these results indicate that gene action significantly influences stress responsiveness and suggest possible chromosomal locations of these genes.