关键词: 黑鲷, 脂肪酸延长酶基因, 生物信息学

Abstract: Black porgy (Acanthopagrus schlegelii) is a marine economic fish with strong resistance to stress. However, it is impossible to overwinter outdoors in the north of Yangtze River, and it is time-consuming and labor-intensive to overwinter indoors every year. The structure and function of  the protein encoded by fatty acid elongase (ELO) gene of A. schlegelii were studied in order to cultivate the strain of A. schlegelii with low temperature tolerance and explore its molecular mechanism. Firstly, the ELO amino acids of five kinds of fish, such as A. schlegelii, Sparus aurata, Siniperca chuatsi, Epinephelus coioides, Cyprinus carpio, were sequenced by DNAman 8 software, and their homology and evolutionary relationship were analyzed. Then, the physicochemical properties, subcellular localization, signal peptide, transmembrane region, splicing site, protein phosphorylation, glycosylation, secondary structure, domain, molecular function and protein interaction of ELO protein of A. schlegelii were analyzed by bioinformatics tools, and homologous modeling and three-dimensional structure prediction were carried out. The results of amino acid sequence alignment showed that the sequence homology between A. schlegelii and other fishes was high. Among the five fishes analyzed, A. schlegelii had the closest genetic relationship with Sparus aurata and the farthest genetic relationship with Cyprinidae fishes. Bioinformatics analysis showed that ELO protein was a basic, small molecule, stable and non-secretory hydrophilic protein, and subcellular localization was in cytoplasm, nucleus and mitochondria. There were 22 splicing sites, 19 phosphorylation sites and 9 lysine saccharification sites in the protein, but there were no glycosylation sites and signal peptides. It contained a variety of secondary structures, among which α-helix was the main one, with one domain and seven transmembrane regions; ELO protein may have direct interaction with other 10 protein, which may affect estrogen synthesis. Through bioinformatics analysis of the structure and function of the protein encoded by ELO gene of A. schlegelii, it was preliminarily determined that it was related to low temperature tolerance. The research results provided a basic theoretical basis for breeding low-temperature resistant strains of A. schlegelii.

Key words: Acanthopagrus schlegelii, fatty acid elongase (ELO) gene, bioinformatics