Search for a command to run...
Nonspecific cytotoxic cell receptor protein type I (NCCRP1), as an important type of receptor protein, plays a key role in the immune process of teleost, which triggers cytotoxic reactions by recognizing and binding to multiple target cells. In this study, the NCCRP1 gene sequence of Megalobrama amblycephala was cloned by PCR technology. Its length was 726 bp and the open reading frame (ORF) was 702 bp, which encoded 233 amino acids, with a relative molecular weight of 26.87 kD. Through homologous sequence retrieval in NCBI, the amino acid sequence of Megalobrama amblycephala NCCRP1 was compared with other fish NCCRP1, and the similarity was as follows: Labeo rohita (87.12%), Carassius auratus (85.84%), Danio rerio (83.26%) and Cyprinus carpio (82.05%). The genetic phylogenetic tree was constructed using the adjacency method. The NCCRP1 gene of Megalobrama amblycephala was clustered into one branch with that of Cyprinidae fish. Megalobrama amblycephala NCCRP1 had the closest genetic relationship with that of Ctenopharyngodon idellus . The NCCRP1 expression in different tissues was detected by qPCR. It was found that the expression level of the NCCRP1 gene was highest in the head kidney, followed by the spleen, liver and posterior kidney. After infection with Aeromonas hydrophila , the expression level of NCCRP1 gene in head kidney, spleen, gill and intestine first increased and then decreased during 21 days. The NCCRP1 expression was reached the peak at 5d in head kidney, spleen and gill, and reached its maximum at 7 d in intestine after infection, which indicated that the NCCRP1 expression could be significantly induced after infection with Aeromonas hydrophila . The maximum relative expression of NCCRP1 gene in head kidney and spleen were 19.84 folds and 7.82 folds, respectively, which were significantly higher than those in intestine (5.32 folds) and gill (6.35 folds). It indicated that Megalobrama amblycephala NCCRP1 might play an important role in the systemic immune tissues of the head kidney and spleen in the process of resisting Aeromonas hydrophila infection.