Partial characterization of porcine obesity gene (OBS) and its localization to chromosome 18 by somatic cell hybrids

Degenerate primers based on human and mouse obesity gene (OBS) sequencing data were used in the reverse transcriptase-polymerase chain reaction (RT-PCR) of total RNA from pig white adipose tissue. Both strands of the resultant pig-specific 325bp DNA fragment were sequenced. Comparison of the obtained sequence with known sequences revealed an 86% identity with the human and 84% identity with the mouse OBS cDNA. The OBS gene was physically mapped to pig chromosome 18 by PCR analysis of somatic cell hybrids, using pig-specific primers. This result is consistent with the recent assignment of the human OBS gene to chromosome 7 and the observation made by comparative mapping that by using a human chromosome 7 specific library two segments of conserved synteny were detected on porcine chromosomes 9 and 18. We conclude the border of conserved synteny to be in the 7q31-7q32 region of the human chromosome.