Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: March 19, 1998
Publication Date: N/A
Technical Abstract: The product of the obese gene, leptin, is secreted by mammalian adipose tissue and functions to regulate appetite and energy expenditure. We have cloned a leptin homolog from broiler chickens by amplification of both genomic DNA and mRNA isolated from liver and adipose tissues. The predicted amino acid sequence of chicken leptin is 94% identical to mouse leptin and >80% identical to bovine, porcine, and human leptins. We have also developed an RT-PCR based assay for chicken leptin mRNAs. Leptin is expressed by both adipose and liver tissues in chickens. The presence of leptin mRNA in the liver correlates with its function as the primary site of lipogenesis in birds. We have also investigated the effects of treatment with either porcine insulin or dexamethasone on leptin expression, previously shown to induce leptin production by mammalian adipocytes. Comparison of the RT-PCR products from treated birds to that of controls indicated a substantial induction of leptin mRNA levels by insulin and dexamethasone in the liver similar to their effect on leptin expression in mammalian adipose tissue. There appears to be no similar induction of leptin expression in chicken adipose tissue by either hormone treatment. A similar mechanism to that described in mammals of energy expenditure and food intake regulation by leptin may exist in birds and be of significant economic importance to the poultry industry.