Molecular analysis of the QM gene from Penaeus monodon and its expression on the different ovarian stages of development.

In present study, a QM gene was obtained from the ovary and neurosecretory organ in eyestalk cDNA library of black tiger prawn (Penaeus monodon). The full-length black tiger prawn QM (PmQM) cDNA contained a 5'-UTR of 41 bp, an ORF of 663 bp encoding a polypeptide of 220 amino acids with molecular weight 25.5 kDa, and a 3'-UTR of 54 bp. Homology analysis of the deduced amino acid sequence of the PmQM with other known QM sequences by MatGAT software revealed that the PmQM was high homology with other invertebrates. A conserved signature sequence of the QM family was found in the PmQM deduced amino acid sequence. Analysis of the tissue expression pattern of the PmQM gene showed that the PmQM mRNA was expressed in all tissues tested, with highest levels in ovary. Furthermore, the PmQM expression was found to be different in three important ovarian stages of development. The results indicated PmQM might play an important role in ovarian development.