The International Complex Trait Consortium

Mapping of Metabolic QTL in Congenic and RI Strains

Grant Morahan1, Anita Holdsworth1, Sof Andrikopolous2, Anne Thorburn2, Joseph Proietto2

1The Walter and Eliza Hall Institute of Medical Research PO Royal Melbourne Hospital Victoria 3050 Australia
2 Department of Medicine, Royal Melbourne Hospital Victoria 3050 Australia

Identification of genes influencing obesity and type 2 diabetes remains a significant challenge. We have used the polygenic obese mouse strain NZO to map genes which regulate various parameters relevant to body weight regulation, eg food intake, physical activity, insulin secretion, fat pad weights, heart size, etc. Congenic mice have been produced to confirm the mapping data and to fine map the QTL loci. A major locus resulting in deficient insulin production was mapped to a 2cM region. We have also examined regulation of insulin production in crosses between the C57BL/6 and DBA/2 strains. Mapping of two loci that affect insulin production was achieved from analysis of backcross mice, and characterization of RIX strains bred from selected BXD RI strains will allow fine mapping of these loci.

[We thank Hui Chen Hsu and John Mountz for providing BXD RI strains. This work supported by the National health and Medical Research Council of Australia]