Meiotic cell cycle

Observations from various systems, including yeast, suggest that phosphorylation and dephosphorylation of proteins play important roles in the mitotic and meiotic cell cycles and the differentiation of germ cells. Extracts from mitotic HeLa cells contained phosphoproteins also present in other mitotic and meiotic cell types, but not in interphase cells (Davis et al., 1983). Exposure of Xenopus oocytes to progesterone results in a burst of protein phosphorylation shortly before GVBD (Mailer et al.,... 

Choi, T Aoki, E, Yamashita, M Nagahama, Y and Kohmoto, K. (1992). Direct activation of the p34cprotein kinase without preceding phosphorylation during meiotic cell cycles in mouse oocytes. Biomed. Res. 13 423-427. 

Nishizawa, M., Okazaki, K., Furuno, N., Watanabe, N., and Sagata, N. (1992). The second-codon rule and autosphophorylation govern the stability and activity of Mos during the meiotic cell cycle in Xenopus oocytes. EMBO J. 11 2433-2446. 

The c-mos proto-oncogene is unique in being specifically expressed in male and female germ cells, where it appears to play a central role in regulating the meiotic cell cycle. Its function is best understood in... 

GermOnline http //www.germonline.org/ GE in mitotic and meiotic cell cycle... 

Fig. 1. Germline transmission from one generation to the next generation in sexual reproduction system. In most vertebrate species, the primary cxx ytes (or immature oocytes) in ovarian tissue pauses their cell cycle at prophase of the first meiosis, resumes the meiosis in response to hormonal signals, re-pauses at metaphase of the second meiotic cell cycle as the secondary oocytes (or mature oocytes), and are subject to ovulation and fertilization. Upon fertilization, eggs undergo a series of extracellular and intracellular reactions/changes, collectively called egg activation that triggers the initiation of development or early embryogenesis. A similar mechanism, although not identical in several sp>ecies, has been shown to be involved in sexual reproduction system in a diverse array of animal species and maybe in some algae and plants.

Faure S, Vigneron S, Doree M, Morin N. 1997. A member of the Ste20/PAK family of protein kinases is involved in both arrest of Xenopus oocytes at G2/ prophase of the first meiotic cell cycle and in prevention of apoptosis. EMBO J 16(18) 5550-5561. 

Tripathi A, Kumar KV, Chaube SK. 2010. Meiotic cell cycle arrest in mammalian oocytes. J Cell Physiol 223(3) 592-600. 

BubRl is a spindle assembly checkpoint protein regulating meiotic cell cycle progression of mouse oocyte. Cell Cycle 9(6) 1112-1121. 

Eberhart C.G., Maines J.Z., and Wasserman S.A. 1996. Meiotic cell cycle requirement for a fly homolog of human Deleted in Azoospermia. Nature 381 783-785. 

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