Molecular Analysis of a Selenoprotein M Gene from Penaeus monodon and its Expression at Different Ovarian Stages of Development

Abstract

In the present study, a Selenoprotein M (SelM) gene was obtained from the ovary and neurosecretory organ in eyestalk cDNA library of Penaeus monodon. Its cDNA sequence consisted of 901 nucleotides including an open reading frame (ORF) 396bp. The open reading frame encoded a peptide of 131 amino acids. Putative SECIS element stem-loop structure of PmSelM mRNA was predicted by SECISearch software. Like the SECIS elements in vertebrate selenoprotein mRNAs, PmSelM SECIS element contains several highly conserved sequences, including a quartet containing non-Watson-Crick base pairs (5′-UGAN and NGAN-3′), and an unpaired AA motif in the apical loop that is separated from the quartet by 11 nucleotides. Analysis of the tissue expression pattern of the PmSelM gene showed that the PmSelM mRNA was expressed in all tested tissues however there was a considerable difference in level of expression in the tissues. High expression levels were observed in the ovary and hepatopancreas of both female and male P. mondon respectively. The expression of PmSelM increased significantly from stage 1 ovary to stage 2-4 ovaries, which belong to rapid development stage ovaries, followed by a significant decrease in the stage 5 ovary (mature ovary). The results indicated PmSelM might play an important role in ovarian development.