International Mammalian Genome Society

A10 Evidence of a Paternally Imprinted Gene Affecting Body Weight in Mice on Mouse Chromosome 7

Madhu Dhar¹, Lisa Webb¹, Laurel Smith¹, David West³ and Dabney Johnson.^1,2. ¹The University of Tennessee Graduate School of Biomedical Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6480, USA; ²Life Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-8077; ³Parke-Davis Laboratory for Molecular Genetics, Alameda, CA 94502

Quantitative trait loci (QTL) analysis of polygenic traits have identified several QTLs affecting either the body weight or body fat content in mice. One of these is linked to the pink-eyed dilution (p) locus on mouse chromosome 7. Using the mice carrying radiation-induced deletions in this region, we have determined that the gene or genes affecting body weight in mice map to the p deletion complex. This effect is observed in hemizygous animals, which carry a wild-type paternal allele and a deletion of the critical region on the maternal allele, suggesting that the gene(s) may be maternally expressed (paternally imprinted). Towards positional cloning of the gene(s) responsible for this phenotype, sequence-ready physical as well as transcript maps of the critical region are being generated. Experiments describing the identification of candidate genes involved in the regulation of body fat content in the mouse will be presented.

Supported by the US Dept of Energy under contract DE-AC05-96OR22464 with Lockheed Martin Energy Research Corp. to DJ and NIH-DK53393 to DW.