The high growth (hg) locus maps to a deletion in mouse chromosome 10

The high growth (hg) locus in mice produces a 30-50% increase in weight gain of homozygous individuals. Here we report that the microsatellite marker D10Mit69 is deleted in high growth mice. The deletion of D10Mit69 was uncovered in a screen of the high growth mouse and its progenitor strains for available markers in the hg region. We demonstrate that hg and D10Mit69 cosegregate in a cross of congenic strains C57BL/6J-hghg x C57BL/6J. These results suggest that deletion of a region around D10Mit69 is responsible for the high growth effect. Marker D10Mit69 will be utilized as an entry point to physical cloning of the hg-containing segment. A dense map of markers around hg constructed here should allow identification of markers in homologous regions in domestic animals and humans, which may be utilized to assess the role of the hg locus in these other species.