The molecular events regulating hormone-induced oocyte activation and meiotic maturation are probably best understood in @entity1238 . In @entity1238 , @entity1420 activates the G2-arrested oocyte, induces entry into M phase of meiosis I (MI) and resumption of the meiotic cell cycles, and leads to the formation of a mature, fertilizable egg. Oocytes of @entity24799 offer several practical advantages over those of @entity1238 , including faster and more synchronous meiotic cell cycle progression, less seasonal variability, and the availability of transgenic approaches. Previous work found several similarities in the pathways regulating oocyte maturation in the two species. Here, we report several additional ones that are conserved in @entity24799 . (1). Injection of @entity70401 mRNA into G2-arrested oocytes activates the MAP kinase cascade and induces the G2/MI transition. (2). Injection of the beta subunit of the kinase CK2 (a negative regulator of @entity70401 and oocyte activation) delays the G2/MI transition. (3). Elevating PKA activity blocks @entity1420 -induced maturation; repressing PKA activity induces entry into MI in the absence of @entity1420 . (4). LF ( @entity6192 lethal factor), which cleaves certain MAP kinase kinases, strongly reduces both the rate and extent of entry into MI. In contrast to the one previously reported major difference between oocytes of the two species, we find that injection of egg cytoplasm ("MPF activity") into G2-arrested @entity24799 oocytes induces entry into meiosis I even when protein synthesis is blocked, just as it does in oocytes of @entity1238 . These results indicate that much of what we have learned from studies of @entity1238 oocytes holds for those of @entity24799 , and suggest that @entity24799 oocytes offer a good experimental system for investigating certain questions that require a rapid, synchronous progression through the G2/meiosis I transition.

Regulation of the G2/M transition in oocytes of XXXX .

@entity6192 :: ('1392', 'Species') :: ['anthrax'] @entity24799 :: ('8364', 'Species') :: ['Xenopus tropicalis', 'X. tropicalis'] @entity70401 :: ('100489962', 'Gene') :: ['Mos'] @entity1238 :: ('8355', 'Species') :: ['Xenopus laevis', 'X. laevis'] @entity1420 :: ('MESH:D011374', 'Chemical') :: ['progesterone']
@entity24799 :: (8364,Species) :: ['xenopus tropicalis']
