Evidence for equal size cell divisions during gametogenesis in a marine green alga Monostroma angicava.
Evidence for equal size cell divisions during gametogenesis in a marine green alga Monostroma angicava.
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DOI：
10.1038/srep13672
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发表时间：
2015-09-03
影响因子：
4.6
通讯作者：
Yoshimura J
中科院分区：
文献类型：
--
作者：
Togashi T;Horinouchi Y;Sasaki H;Yoshimura J
在细胞分裂中，子细胞的相对大小在配子发生和胚胎发生中起着重要作用。两种交配类型之间配子大小的差异是性选择的基础。子细胞的大小是调控细胞分裂的关键因素。在卵裂中，细胞分裂的形式（大小相等/不等）决定了每个卵裂球的发育命运。然而，细胞分裂形式的严格验证很少得到证实。我们不能仅通过分析子细胞的平均大小来区分相等和不相等的细胞分裂，因为它们的平均值可能是相同的。相反，子细胞大小的分散取决于细胞分裂的形式。在此基础上，我们表明，配子发生在海洋绿色，Monostroma angicava，表现出相同大小的细胞分裂。每种交配型配子体积的方差和平均值与同步等体积细胞分裂的预测结果一致。配子大小实际上只取离散值。这是解释海洋绿色藻类同花受精和异花受精多样性演化的关键理论假设。我们的研究结果表明，生殖细胞采用相同大小的细胞分裂过程中配子。
In cell divisions, relative size of daughter cells should play fundamental roles in gametogenesis and embryogenesis. Differences in gamete size between the two mating types underlie sexual selection. Size of daughter cells is a key factor to regulate cell divisions during cleavage. In cleavage, the form of cell divisions (equal/unequal in size) determines the developmental fate of each blastomere. However, strict validation of the form of cell divisions is rarely demonstrated. We cannot distinguish between equal and unequal cell divisions by analysing only the mean size of daughter cells, because their means can be the same. In contrast, the dispersion of daughter cell size depends on the forms of cell divisions. Based on this, we show that gametogenesis in the marine green alga, Monostroma angicava, exhibits equal size cell divisions. The variance and the mean of gamete size (volume) of each mating type measured agree closely with the prediction from synchronized equal size cell divisions. Gamete size actually takes only discrete values here. This is a key theoretical assumption made to explain the diversified evolution of isogamy and anisogamy in marine green algae. Our results suggest that germ cells adopt equal size cell divisions during gametogenesis.