Physiological polyspermy: Selection of a sperm nucleus for the development of diploid genomes in amphibians
Physiological polyspermy: Selection of a sperm nucleus for the development of diploid genomes in amphibians
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生理多精受精：选择精子核以发育两栖动物二倍体基因组
DOI：
10.1002/mrd.23235
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Hara Y
中科院分区：
文献类型：
--
作者：
Iwao Y;Kimoto C;Fujimoto A;Suda A;Hara Y
在卵子受精过程中，精子和卵核之间的结合是混合遗传物质为下一代创造新的二倍体基因组所必需的。在大多数动物中，只有一个精子进入卵子（单精子），但一些动物表现出生理性多精子，其中几个精子在正常受精过程中进入卵子。然而，即使在多精卵中，也只有一个精核与卵核形成合子核。在有尾目两栖动物中，精核在卵细胞质中选择的细胞和分子机制已经被很好地研究。主精核发育成一个较大的精星，与卵核接触形成合子核，而其它副精核则不能接近卵核。二倍体合子核诱导卵裂并参与胚胎发育，而副精核则发生固缩和退化。我们提出了几个模型来解释选择一个精子核和副精子核退化的机制。通过与其他多精物种的比较，讨论了生理性多精在动物繁殖中的作用。
The union between a sperm and an egg nucleus in egg fertilization is necessary to mix genetic materials to create a new diploid genome for the next generation. In most animals, only one sperm is incorporated into the egg (monospermy), but several animals exhibit physiological polyspermy in which several sperms enter the egg during normal fertilization. However, only one sperm nucleus forms the zygote nucleus with the egg nucleus, even in a polyspermic egg. The cellular and molecular mechanisms involved in the selection of sperm nuclei in the egg cytoplasm have been well investigated in urodele amphibians. The principal sperm nucleus develops a larger sperm aster and contacts the egg nucleus to form a zygote nucleus, whereas other accessory sperm nuclei are unable to approach the egg nucleus. The diploid zygote nucleus induces cleavage and participates in embryonic development, whereas the accessory sperm nuclei undergo pyknosis and degenerate. We propose several models to account for the mechanisms of the selection of one sperm nucleus and the degeneration of accessory sperm nuclei. The roles of physiological polyspermy in animal reproduction are discussed by comparison with other polyspermic species.