The leptin receptor gene (LEPR) maps to porcine chromosome 6

The murine autosomal recessive mutations obese (ob), diabetes (db), and fatty (fa) were first reported in the 1960s. The phenotypes of animals homozygous for these mutations include severe, early-onset obesity, insulin resistance, and susceptibility to diabetes. The ob gene has recently been cloned in human and mouse and its protein product identified as leptin. Subsequent research led to the identification of a receptor for leptin in mice (OB-R). The gene for OB-R was shown to map to within a 5.1-cM interval of mouse Chr. 4 which contains the db locus. This report was followed by two studies providing evidence that db was the gene encoding OB-R. A recent report by Chua and associates has confirmed that db, fa and OB-R are the same gene. The mouse leptin receptor gene has now been assigned the symbol, Lepr, which replaces the previously used symbols OB-R and Obr. Mapping of the human leptin receptor gene (LEPR) has also recently been reported. The assignment of LEPR to porcine Chr. 6q3.3-3.5 is in agreement with the previous assignment of this gene to human Chr 1p32 since bidirectional chromosome painting analysis has demonstrated correspondence between these human and porcine chromosomal segments. This information extends the comparative mapping information for LEPR since it has also been mapped to homologous segments of mouse Chr 4 and rat Chr 5. (DBO)