Meiotic induction by Xenopus cyclin B is accelerated by coexpression with mosXe.
We have investigated the relationship between Xenopus laevis c-mos (mosXe) and the cyclin B component of maturation-promoting factor. Microinjection of Xenopus oocytes with in vitro-synthesized RNAs encoding Xenopus cyclin B1 or cyclin B2 induces the progression of meiosis, characterized by germinal vesicle breakdown (GVBD). By preinjecting oocytes with a mosXe-specific antisense oligonucleotide, we show that GVBD induced by cyclin B does not require expression of the mosXe protein. GVBD induced by cyclin B proceeds significantly faster than GVBD induced by progesterone or MosXe. However, coinjection of RNAs encoding cyclin B1 or cyclin B2 with mosXe RNA results in a 2.5- to 3-fold acceleration in GVBD relative to that induced by cyclin B alone. This acceleration of GVBD does not correlate with changes in the level of cyclin B1 and cyclin B2 phosphorylation.
Freeman
R S
RS
Department of Chemistry, University of California, San Diego, La Jolla 92093-0322.
Ballantyne
S M
SM
Donoghue
D J
DJ
D000818:Animals; D016213:Cyclins / Q000378:metabolism / Q000502:physiology*; D015870:Gene Expression; D016200:Maturation-Promoting Factor / Q000502:physiology*; D008540:Meiosis; D010766:Phosphorylation; D011233:Precipitin Tests; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D017231:Proto-Oncogene Proteins c-mos; D014982:Xenopus laevis / Q000502:physiology*
D016213:Cyclins; D011518:Proto-Oncogene Proteins; D017231:Proto-Oncogene Proteins c-mos; D016200:Maturation-Promoting Factor