INHERITED NON-AUTOSOMAL EFFECTS ON BODY-FAT IN F-2 MICE DERIVED FROM AN AKR J X SWR/J CROSS/

In this study we describe the contribution of matrilineal and patrilin eal effects on the adiposity, body weight, and on the weights of indiv idual fat pads in F-2, male mice derived from an SWR/J x AKR/J cross. AKR/J mice become obese after 12 weeks on a high-fat diet, whereas SWR /J mice remain relatively lean. Here we report that mice with AKR mate rnal and AKR paternal grandmothers have significantly larger epidydima l and retroperitoneal fat pads than those with SWR maternal and patern al grandmothers. However, grandparental strain had no effect on the ov erall adiposity (AI) or the weights of the inguinal, subcutaneous or m esenteric fat pads. The strain of the paternal grandparents had a smal l but significant effect on body weight. These effects can be attribut ed to in utero effects, imprinting effects, cytoplasmic and/or Y chrom osome transmission of factors controlling body fat. We also describe t he presence of a quantitative trait locus (QTL) on Chromosome X, close to DXMit174, which is linked to adiposity, body weight and to the wei ghts of the individual fat depots. However. this QTL is not responsibl e for the grandparental strain effects described above.