Cloning and expression analysis of serine hydroxyl methyltransferase (SHMT) genes from Exopalaemon carinicauda

Abstract:

In this study, based on the transcriptome of Exopalaemon carinicauda under hunger stress, SHMT genes were obtained by rapid amplification of cDNA ends (RACE) (GenBank accession No: MH013225). The full-length cDNA of the SHMT gene was 1855 nucleotides and contained an open reading frame (ORF) of 1407 bp, encoding a protein of 468 amino acid residues, with the predicted molecular weight of 152.55 kDa, and theoretical isoelectric point of 4.90. Multiple sequence alignment and phylogenetic analysis indicated that E. carinicauda SHMT gene is most homologous (96%) with that of Eurytemora affinis. The expression pattern of SHMT gene in different tissues was analyzed by qRT-PCR. The results showed that SHMT gene was expressed in all tissues of E. carinicauda. Transcript levels were high in the heart and ovary and were significantly higher in the ovary than in the other tissues. The results of different concentrations of Cd2+ stress showed that the expression patterns of lower cadmium stress were basically the same, showing a trend of alternately first increasing and then decreasing. Under high concentration of Cd2+ stress, the expression level was extremely low; and not even detected in these tissues. This suggests that high concentration of Cd2+ stress can inhibit the expression of the SHMT gene. The specific mechanism needs further study.