A Novel Gene with a vWD Domain and Three Kazal-Type Domains: Molecular Cloning and Expression in the Ovary of the Oriental River Prawn, Macrobrachium nipponense

A novel gene encoding a von Willebrand factor D (vWD) domain and three Kazal-type domains was firstly indentified from the ovary of the oriental river prawn Macrobrachium nipponense and this gene was named as MnvWD-Kazal. Bioinformatics analyses showed that this gene encodes a protein of 857 amino acids with a predicted molecular mass of 92.7 kDa. Real-time quantitative PCR (RT-QPCR) analyses revealed that the level of MnvWD-Kazal mRNA expression varied in the developing ovary and substantially differed between other tissues. In the ovary, the level of MnvWD-Kazal expression gradually increased from the perinucleolus (PN) stage to the yolk granule (YG) stage, and then abruptly decreased at the sexual maturation (MA) stage. The maximum expression occurred in the YG stage and the minimum was at the paracmasis (PM) stage. The expression level of MnvWD-Kazal in the intestine was much higher than that in other tissues. The differential expressions of MnvWD-Kazal at different stages of the ovary suggest that this novel gene may play a critical role in the oocyte maturation of M. nipponense.