The role of cyclins in the maturation of Patella vulgata oocytes.

AUTOR(ES)

van Loon, A E

RESUMO

We have cloned and sequenced the cDNAs encoding Patella vulgata cyclins A and B. The cDNA clones contain an open reading frame of 426 and 408 amino acids respectively, which present similarity with cyclins from other species. Cyclin A and B RNAs are present as polyadenylated and non-polyadenylated RNA in prophase oocytes and are completely polyadenylated in metaphase I. During the first cleavages after fertilization the level of cyclin A and B mRNAs is high and drops when the free swimming stage is reached. Using p13suc1-Sepharose bead precipitation we demonstrate that cyclin synthesis is triggered during maturation and that inhibition of protein synthesis makes the cyclins disappear rapidly from the metaphase I oocytes, which shift to interphase condition. By microinjecting antisense oligonucleotides into metaphase I oocytes, we demonstrate that in vivo ablation of cyclin A and B messengers together gives the same result, whereas microinjection of only one oligonucleotide does not show any effect.

Documentos Relacionados

• Evidence for a role of protein kinase C zeta subspecies in maturation of Xenopus laevis oocytes.
• Microinjected progesterone reinitiates meiotic maturation of Xenopus laevis oocytes.
• tpr-met oncogene product induces maturation-producing factor activation in Xenopus oocytes.
• Xenopus homolog of the mos protooncogene transforms mammalian fibroblasts and induces maturation of Xenopus oocytes.
• Increased phosphorylation of ribosomal protein S6 during meiotic maturation of Xenopus oocytes.