Effect of genetic cross on the detection of quantitative trait loci and a novel approach to mapping QTLs

A genome-wide scan was conducted in two Fz intercrosses, C57BL/6J (B6) x DBA/2J (D2) and BALB/cJ (C) x LP/J (LP), for three different phenotypes: basal locomotor activity, ethanol-induced locomotor activity, and haloperidol-induced catalepsy. For basal activity, significant quantitative trait loci (QTLs, LOD greater than or equal to 4.3) were detected on chromosomes 9 and 19 for the C x LP intercross and chromosome 1 for the B6 x D2 intercross. Significant QTLs for ethanol-induced activation were detected on chromosome 6 for the C x LP intercross, and on chromosomes 1 and 2 for the B6 x D2 intercross. For haloperidol-induced catalepsy, significant QTLs were detected on chromosome 14 (two different QTLs) in the C x LP intercross, and chromosomes 1 and 9 in the B6 x D2 intercross. These data illustrate the importance of the genetic cross for QTL detection. Finally, the data reported here, and elsewhere, are also used to demonstrate a novel approach to QTL detection and localization. (C) 2001 Elsevier Science Inc. All rights reserved.