The open reading frame of black tiger shrimp (Penaeus monodon) cyclin B (Pmcyclin B) was identified, based on cDNA sequence registered in GenBank (accession No. EF015590). The target sequence was 1206 bp, corresponding to 401 amino acids. Two conserved signature sequences of the cyclin B gene family were found in the Pmcyclin B deduced aa sequence. Temporal expression of Pmcyclin B in different tissues, including ovary, lymphoid organ, brain, blood, muscle, heart, gill, hepatopancreas, and intestine, were quantified by quantitative real time PCR.
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.