Participation of calmodulin in ovarian maturation induced by eyestalk ablation in red swamp crayfishProcambarus clarkii

Abstract

Eyestalk ablation is involved in the ovarian development and maturation of crustaceans held in captivity. However, the molecular mechanism of eyestalk ablation induction of ovarian maturation remains unclear. Reports show that calmodulin (CaM) transduces Ca2+ signals into downstream effects, which is a potent critical factor in the induction course of Penaeus monodon. The effects of unilateral eyestalk ablation on the ovarian growth and maturation of domesticated female Procambarus clarkii were investigated in this study. The expression patterns of CaM gene during the maturation course induced by eyestalk ablation were analysed using reverse-transcriptase quantitative PCR. RNA interference technique was used to elucidate the role of CaM in the crayfish eyestalk ablation mechanism to induce ovarian maturation. The results demonstrated that the expression level of CaM was significantly induced to 8.7-fold 1 day after the eyestalk ablation (P < 0.05), and then gradually reduced on the following days. The CaM knockdown which is lethal to crayfish inhibited the ovarian maturation induced by eyestalk ablation. Thus, the CaM calcium signalling pathway is important in the induction of ovarian maturation by eyestalk ablation in crustaceans.