Abstract:
Embryo development depends upon maternally derived materials. Mammalian oocytes undergo extreme asymmetric cytokinesis events, producing one large egg and two small polar bodies. During cytokinesis in somatic cells, the midbody and subsequent assembly of the midbody remnant, a signaling organelle containing RNAs, transcription factors and translation machinery, is thought to influence cellular function or fate. The role of the midbody and midbody remnant in gametes, in particular, oocytes, remains unclear. Here, we examined the formation and function of meiotic midbodies (mMB) and mMB remnants using mouse oocytes and demonstrate that mMBs have a specialized cap structure that is orientated toward polar bodies. We show that that mMBs are translationally active, and that mMB caps are required to retain nascent proteins in eggs. We propose that this specialized mMB cap maintains genetic factors in eggs allowing for full developmental competency.
摘要:
胚胎发育取决于母体来源的材料。哺乳动物卵母细胞经历极端不对称的胞质分裂事件,产生一个大鸡蛋和两个小极体。在体细胞的胞质分裂过程中,中体和随后的中体残余的组装,含有RNA的信号细胞器,转录因子和翻译机制,被认为会影响细胞功能或命运。中体和中体残余在配子中的作用,特别是,卵母细胞,尚不清楚。这里,我们使用小鼠卵母细胞检查了减数分裂中体(mMB)和mMB残留物的形成和功能,并证明mMB具有朝向极体的特殊帽结构。我们证明了MBs是平移活跃的,并且mMB帽需要保留鸡蛋中的新生蛋白质。我们建议这种专门的mMB帽可以保持鸡蛋中的遗传因素,从而具有完整的发育能力。