Centre for Organismal Studies (COS), Heidelberg University, Im Neuenheimer Feld 230, Heidelberg 69120, Germany.
Zentrum für Molekulare Biologie der Universität Heidelberg (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, Heidelberg D-69120, Germany.
Nat Commun. 2017 Jan 18;8:14090. doi: 10.1038/ncomms14090.
The assembly of the first centrosome occurs upon fertilisation when male centrioles recruit pericentriolar material (PCM) from the egg cytoplasm. The mechanisms underlying the proper assembly of centrosomes during early embryogenesis remain obscure. We identify Wdr8 as a novel maternally essential protein that is required for centrosome assembly during embryonic mitoses of medaka (Oryzias latipes). By CRISPR-Cas9-mediated knockout, maternal/zygotic Wdr8-null (m/zWdr8) blastomeres exhibit severe defects in centrosome structure that lead to asymmetric division, multipolar mitotic spindles and chromosome alignment errors. Via its WD40 domains, Wdr8 interacts with the centriolar satellite protein SSX2IP. Combining targeted gene knockout and in vivo reconstitution of the maternally essential Wdr8-SSX2IP complex reveals an essential link between maternal centrosome proteins and the stability of the zygotic genome for accurate vertebrate embryogenesis. Our approach provides a way of distinguishing maternal from paternal effects in early embryos and should contribute to understanding molecular defects in human infertility.
当精子中心体从卵子细胞质中招募中心体周围物质（PCM）时，第一个中心体的组装发生在受精时。在早期胚胎发生过程中，中心体正确组装的机制仍不清楚。我们鉴定出 Wdr8 是一种新的母源必需蛋白，它是在斑马鱼胚胎有丝分裂过程中中心体组装所必需的。通过 CRISPR-Cas9 介导的敲除，母源/合子 Wdr8 缺失（m/zWdr8）的胚胎细胞表现出严重的中心体结构缺陷，导致不对称分裂、多极有丝分裂纺锤体和染色体排列错误。通过其 WD40 结构域，Wdr8 与中心体卫星蛋白 SSX2IP 相互作用。通过靶向基因敲除和体内重建母源必需的 Wdr8-SSX2IP 复合物，揭示了母源中心体蛋白与合子基因组稳定性之间的重要联系，对于准确的脊椎动物胚胎发生至关重要。我们的方法提供了一种在早期胚胎中区分母源和父源效应的方法，应该有助于理解人类不育症中的分子缺陷。
