Purpose This study cloned cDNA of COL1A2 gene from Niber coibor, analyzed the molecular characteristics, tissue distribution and expression of collagen, to lay a theoretical foundation for the study of collagen metabolism mechanism in fish.
Methods The full-length sequence of COL1A2 gene of N. coibor was obtained through rapid amplification of cDNA ends (RACE) technology, and then systematically analyzed using bioinformatics analysis method to explore its molecular characteristics and tissue expression.
Results The COL1A2 cDNA was 5 826 bp in full-length and encoded a polypeptide of 1 352 amino acids. BLAST homology comparison and phylogenetic tree analysis revealed that the N. coibor and Larimichthys crocea should belong to Sciaenidae, having the closest relatives, and the amino acid sequence homology of COL1A2 was the highest (96.60%). Bioinformatics analysis showed that COL1A2 contained all the characteristics of type I collagen in vertebrates identified, such as the same signal peptides, C-propeptide and N-propeptide domains, triple helix domains and so on. qRT-PCR results showed that the expression level of COL1A2 in the swim bladder of N. coibor was significantly higher than that in other tissues (P<0.05). It was consistent with the distribution pattern of collagen in different tissues.
Conclusion The COL1A2 gene of N. coibor (GenBank accession number: MK641513) is cloned for the first time. The tissue expression specificity of this gene is one of the reasons for the differential depositon of collagen. The results of the study will help to further study the collagen biosynthetic pathway and regulation mechanism in N. coibor.