Molecular Characterization and Tissue Expression of cbx2 Gene in Paralichthys olivaceus

doi:10.13560/j.cnki.biotech.bull.1985.2018-0995

Abstract

Abstract: In order to identify the cbx2 gene of chromobox homolog（CBX）and its expression in the gonad of Paralichthys olivaceus,the cDNA sequence of cbx2 gene was obtained by PCR cloning and sequencing. The physicochemical properties and spatial structure of CBX2 protein were analyzed online by bioinformatics methods,and the gene structure,amino acid homology and phylogenetic evolution of cbx2 in vertebrates were compared. The expression of cbx2 gene in different adult tissues of P. olivaceus was detected by RT-PCR. The results showed that the obtained cbx2 cDNA had an open reading frame of 1 584 bp,encoding 527 amino acids in P. olivaceus,and the molecular weight and isoelectric point of the reduced protein was 56 578.98 and 10.03,respectively. The CBX2 protein was an alkaline and hydrophilic protein,had no signal peptide and no transmembrane area,and the amino acid encoding the protein had the highest content of serine（Sr）. The spatial structure analysis revealed that the CBX2 protein was mainly composed of α-helix and random coil,and its secondary structure contained one chromatin domain and four low complexity regions,and the chromatin domain was often binding to methylated amino acids. The gene structure,amino acid homology,and phylogenetic analysis indicated that the cbx2 gene was more conserved in the evolution of vertebrate. The gene structure of cbx2 was more similar to that of Oreochromis niloticus and Oryzias latipes,and its amino acid homology was the highest with Seriola dumerili,which was 89%. The RT-PCR showed that the expression of cbx2 mRNA was the highest in the testis,the second one in the ovary,but quite low expressions in other tissues. All above results suggest that cbx2 gene plays a key role in the gonad development of P. olivaceus.

Key words: Paralichthys olivaceus, cbx2, gonad, bioinformatics analysis, RT-PCR

WANG Xin-yan, ZHANG Jun-ling, SHI Zhi-yi. Molecular Characterization and Tissue Expression of cbx2 Gene in Paralichthys olivaceus[J]. Biotechnology Bulletin, 2019, 35(4): 69-75.

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