Expression of cell-cycle regulators during Xenopus oogenesis.
In full-grown Xenopus oocytes, cell-cycle regulators and an inactive form of maturation/M phase promoting factor (pre-MPF) are stored ready to bring about a specific cell cycle for oocyte maturation. We examined the expression pattern of these cell-cycle regulators as well as pre-MPF formation during oogenesis. Cdc2 and Cyclin B2 were already present in stage I oocytes and pre-MPF formation was also detected in stage I oocytes. Some negative regulators of MPF, Myt1 and Chk1, were synthesized early in oogenesis. In contrast, positive regulators of MPF, MEK, MAPK and Cdc25C, were mainly synthesized late in oogenesis. Northern blotting analysis suggested that the synthesis of these cell-cycle regulators was controlled by translation.
Furuno
Nobuaki
N
Division of Differentiation Mechanism, Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8526, Japan. nfuruno@hiroshima-u.ac.jp
Kawasaki
Ayako
A
Sagata
Noriyuki
N
D000818:Animals; D002453:Cell Cycle / Q000235:genetics* / Q000502:physiology; D018797:Cell Cycle Proteins / Q000096:biosynthesis / Q000235:genetics; D019926:Cyclin B / Q000096:biosynthesis / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D016200:Maturation-Promoting Factor / Q000096:biosynthesis / Q000235:genetics; D009866:Oogenesis / Q000235:genetics* / Q000502:physiology; D010053:Ovary / Q000378:metabolism*; D011498:Protein Precursors / Q000096:biosynthesis / Q000235:genetics; D014981:Xenopus
D018797:Cell Cycle Proteins; D019926:Cyclin B; D011498:Protein Precursors; C067034:maturation-promoting factor precursor; D016200:Maturation-Promoting Factor