Cyclin B protein undergoes increased expression and nuclear relocation during oocyte meiotic maturation of the freshwater prawn Macrobrachium rosenbergii and the Chinese mitten crab Eriocheir sinensis

• Published in: Gene Vol. 758; p. 144955
• Main Authors: Feng, Haiyang, Dong, Yao-Ting, Liu, Xue, Qiu, Gao-Feng
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 20.10.2020
• Subjects: Cyclin B; Eriocheir sinensis; Macrobrachium rosenbergii; Oocyte maturation; MPF; ORF; CRS; Eriocheir sinensis; Macrobrachium rosenbergii; lVt; MIH; GVBD; Cyclin B; LH; NES; Oocyte maturation; ELISA
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/j.gene.2020.144955

•Cyclin B protein is present in the immature oocytes, and undergoes increased expression at GVBD in both crab and prawn.•Cyclin B protein relocate from the cytoplasm to the nucleus during oocytes meiotic maturation.•Similar expression pattern of the cyclin B protein was found in the oocyte maturation of the prawn and the crab. Cyclin B functions as a regulatory protein through association with its catalytic partner Cdc2 kinase forming M−phase promoting factor (MPF), which plays a central role in the meiotic maturation of oocyte. To gain insight into the molecular events, we here cloned a cyclin B cDNA from the ovary of the prawn Macrobrachium rosenbergii and compared its spatial–temporal expression patterns during oocyte maturation with those of crab Eriocheir sinensis. The prawn cyclin B cDNA encodes a 398 amino acid protein with predicted molecular weight of 45.16 kDa. Immunodetection of cyclin B protein by Western blot showed that a target band of approximately 53 kDa protein in the prawn ovaries at both late vitellogenesis (lVt) and germinal vesicle breakdown (GVBD) stages, whereas a 41 kDa band was present in the crab ovaries. Cyclin B protein expression changes indicating that the newly synthesis of cyclin B proteins could be required for GVBD in both prawn and crab. Immunohistochemical analysis revealed that both the prawn and crab cyclin B proteins, were localized in the ooplasm of previtellogenic oocytes, then relocated into germinal vesicle at vitellogenesis stage and localized on meiotic spindle at M phase. These similar behaviors suggested that the prawn and the crab cyclin B proteins associated with Cdc2 kinase have conserved roles in inducing GVBD and regulating the formation of meiotic spindle. The similar expression patterns of the cyclin B proteins during oocyte maturation implicated that the molecular mechanisms for MPF activation could be identical between the prawn and the crab.