Abstract: The study was aimed to obtain carp iNOS cDNA full-length sequence, and investigate the changes in peripheral blood leukocyte expression of iNOS in the stimulation of different mitogens.Based on EST sequences of iNOS that obtained from carp normal peripheral blood leukocytes cDNA library, full-length cDNA sequence of carp iNOS was successfully amplified by using gene library screening and rapid-amplification of cDNA 5'ends (5'-RACE) method.Carp peripheral blood leukocytes were divided into control and experimental groups and cultured.The experimental groups were stimulated by LPS (1.0 μg/mL) and ConA (1.0 μg/mL) for 4 and 12 h, respectively.And control groups were in the same cultured conditon time without mitogen stimulated.Real-time PCR was used to detect the expression of iNOS in peripheral blood leukocytes of each group.The results showed that the cDNA fragment was total 3 704 bp containing 74 bp 5'untranslated region (UTR), 246 bp 3'UTR and a 3 384 bp ORF encoding 1 127 amino acids.Sequence homology analysis showed that the amino acid sequence of carp iNOS shared 100% identity with Carassius auratus.After LPS and ConA stimulation, the iNOS expression of peripheral blood leukocytes in the experimental groups were increased, and the expression in the short time stimulation condition (4 h) was higher than the long time (LPS 12 h; ConA 24 h).In conclusion, iNOS expression of peripheral blood leukocytes was raised after LPS and ConA stimulation, suggesting that there were dynamic changes in the inflammation.

Key words: Cyprinus carpio; iNOS; cDNA clones; peripheral blood leukocytes; differential expression analysis