Horev, G., Institute of Animal Science, Agric. Res. Org., Volcani Ctr., P., Bet Dagan, Israel
Einat, P., QBI Enterprises Ltd, 70400, Nes-Ziona, Israel
Aharoni, T., Institute of Animal Science, Agric. Res. Org., Volcani Ctr., P., Bet Dagan, Israel
Eshdat, Y., Institute of Horticulture, Agric. Res. Org., Volcani Ctr., P., Bet Dagan, Israel
Friedman-Einat, M., Institute of Animal Science, Agric. Res. Org., Volcani Ctr., P., Bet Dagan, Israel

The mammalian leptin receptor (LEPR) (formerly OB-R) mediates the weight regulatory effects of the circulating hormone leptin. The extreme obese phenotype of recessive mutations in the mouse leptin or LEPR genes (ob/ob and db/db mice, respectively) indicate the high potential of these genes for medical and agricultural research. In this paper, we report on the cloning of the full-length chicken leptin receptor (CLEPR) cDNA, which is the first non- mammalian cloning of a LEPR gene. The CLEPR gene shares a relatively low sequence similarity with its mammalian counterparts, with an average of 60% identical nucleotides. However, comparison between the predicted protein sequences has shown a tight conservation of most previously characterized LEPR motifs and essential tyrosine residues. Similarities between the chicken and the mammalian LEPR genes were also observed in the pattern of mRNA expression. The identification of the CLEPR gene should facilitate the study of the molecular mechanism involved in the regulation of body growth and composition in avian. (C) 2000 Elsevier Science Ireland Ltd.