TRANSITION DU STADE PACHYTENE AU STADE DIPLOTENE DE LA MEIOSE CHEZ XENOPUS LAEVIS. ETUDE CYTOCHIMIQUE ET AUTORADIOGRAPHIQUE

Abstract

The transition from pachytene to diplotene stages is concomitant with the migration of cytoplasmic proteins into the nucleus, into the chromosomes and the nuclear sap. At that time, an important RNA synthesis begins in the germinal vesicle of the young diplotene oocyte and will persist throughout oogenesis. Protease inhibitors (TLCK, TPCK, TAME) prevent the decondensation of pachytene chromosomes, while the previous stages of meiosis continue normally. The use of 3H TAME shows that this molecule enters the germinal cells and their nuclei. Incorporation of 3H uridine into RNA and of L 3H leucine into proteins is also decreased in the presence of the proteolytic enzyme inhibitors. It is logical to think that the unfolding of the lampbrush chromosomes is accompanied by the derepression of numerous sites of RNA synthesis.SCOPUS: ar.jinfo:eu-repo/semantics/publishe