Genetic polymorphism and expression analysis of leptin gene in rabbit

Leptin plays an important role in the regulation of feed intake, energy metabolism, growth and reproduction of rabbit. We used the polymerase chain reaction- single stranded confirmation polymorphism (PCR-SSCP) technique to screen for DNA polymorphisms of the leptin gene in 150 New Zealand White rabbits. In all the New Zealand White rabbits, we amplified different regions of the leptin gene. PCR-SSCP of all these fragments revealed monomorphic pattern. All the amplified fragments of leptin gene were monomorphic, which is in contradiction to many earlier reports of mammalian species. All the fragments were sequenced and compared with the available sequences of different species. The nucleotide sequence analysis indicated that the per cent similarity of leptin gene fragments of New Zealand White rabbit with rat, mouse, cattle and pig was 79.6-87.5%. At various places, the amino acids and protein were different in New Zealand White rabbit as compared to rat, mouse, cattle and pig. For relative quantification, total RNA was isolated from liver tissues collected at 2 different stages of growth i.e. pre-weaning and post-weaning. Our results indicate no significant differences in the mRNA expression of leptin between two different stages of growth.