美国西北大学Thomas V. OHalloran团队报道了金属离子通量控制两栖动物的受精。相关研究成果发表在2021年6月21日出版的《自然—化学》。

哺乳动物卵母细胞在受精过程中锌含量和定位发生了重大变化，其中最引人注目的是锌火花中超过100亿个锌离子的快速胞吐。

该文中，研究人员报道了两栖动物非洲爪蟾卵的受精也启动了一个锌火花，该火花与动态钙波协同作用穿过细胞表面。锌的胞吐伴随着新发现的细胞内锰的丢失。基于同步辐射的X射线荧光和分析电子显微镜显示，锌和锰被隔离在一个皮质颗粒系统中，该系统在动物极部非常丰富。通过电子-核双共振研究，研究人员排除了完整卵中Mn2+与磷酸盐或含氮配体的络合作用，但数据与羧酸盐配位环境一致。

研究人员观察结果表明，锌和锰通量是脊椎动物受精的一个保守特征，它们具有多精受精生理障碍的一部分功能。

附：英文原文

Title: Metal ion fluxes controlling amphibian fertilization

Author: John F. Seeler, Ajay Sharma, Nestor J. Zaluzec, Reiner Bleher, Barry Lai, Emma G. Schultz, Brian M. Hoffman, Carole LaBonne, Teresa K. Woodruff, Thomas V. OHalloran

Issue&Volume: 2021-06-21

Abstract: Mammalian oocytes undergo major changes in zinc content and localization to be fertilized, the most striking being the rapid exocytosis of over 10 billion zinc ions in what are known as zinc sparks. Here, we report that fertilization of amphibian Xenopus laevis eggs also initiates a zinc spark that progresses across the cell surface in coordination with dynamic calcium waves. This zinc exocytosis is accompanied by a newly recognized loss of intracellular manganese. Synchrotron-based X-ray fluorescence and analytical electron microscopy reveal that zinc and manganese are sequestered in a system of cortical granules that are abundant at the animal pole. Through electron–nuclear double-resonance studies, we rule out Mn2+ complexation with phosphate or nitrogenous ligands in intact eggs, but the data are consistent with a carboxylate coordination environment. Our observations suggest that zinc and manganese fluxes are a conserved feature of fertilization in vertebrates and that they function as part of a physiological block to polyspermy.

DOI: 10.1038/s41557-021-00705-2

Source: https://www.nature.com/articles/s41557-021-00705-2