Characteristics of Cyclin B and its potential role in regulating oogenesis in the red claw crayfish (Cherax quadricarinatus).

Cyclin B is a regulatory subunit of maturation-promoting factor (MPF), which has a key role in the induction of meiotic maturation of oocytes. MPF has been studied in a wide variety of animal species; however, its expression in crustaceans is poorly characterized. In this study, the complete cDNA sequence of Cyclin B was cloned from the red claw crayfish, Cherax quadricarinatus, and its spatiotemporal expression profiles were analyzed. Cyclin B cDNA (1779 bp) encoded a 401 amino acid protein with a calculated molecular weight of 45.1 kDa. Quantitative real-time PCR demonstrated that Cyclin B mRNA was expressed mainly in the ovarian tissue and that the expression decreased as the ovaries developed. Immunofluorescence analysis revealed that the Cyclin B protein relocated from the cytoplasm to the nucleus during oogenesis. These findings suggest that Cyclin B plays an important role in gametogenesis and gonad development in C. quadricarinatus.