Positive selection is a general phenomenon in the evolution of abalone sperm lysin.
Positive selection is a general phenomenon in the evolution of abalone sperm lysin.
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DOI：
10.1093/oxfordjournals.molbev.a040200
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发表时间：
1995-03
影响因子：
10.7
通讯作者：
Youn-Ho Lee;Tatsuya Ota;V. D. Vacquier
中科院分区：
文献类型：
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作者：
Youn-Ho Lee;Tatsuya Ota;V. D. Vacquier
溶素是鲍鱼精子利用的一种16kDa的顶体蛋白质，其作用是在卵卵黄膜（VE）上形成一个孔。溶素与VE的相互作用是物种选择性的，并且是限制异源（跨物种）受精的多步骤受精过程中的一个步骤。因此，溶素的进化可能在建立物种间的前合子生殖隔离中发挥作用。此前，我们对七种加州鲍鱼物种的精子溶素cDNA进行了测序，并表明积极的达尔文选择促进了它们的分歧。在本文中，另外13个溶素序列代表来自日本，台湾，澳大利亚，新西兰，南非和欧洲的物种。总共20个序列代表了迄今为止最广泛的受精蛋白分析。系统发育分析将序列分为两个主要分支，一个由来自北方太平洋（加州和日本）的物种组成，另一个由来自世界其他地区的物种组成。核苷酸替换分析表明，正选择是这种受精蛋白进化的一般过程。核苷酸和密码子使用偏倚的分析表明，这两个参数都不能解释支持正选择的稳健数据。导致溶素正选择的选择压力仍然未知。
Lysin is a 16kDa acrosomal protein used by abalone sperm to create a hole in the egg vitelline envelope (VE). The interaction of lysin with the VE is species-selective and is one step in the multistep fertilization process that restricts heterospecific (cross-species) fertilization. For this reason, the evolution of lysin could play a role in establishing prezygotic reproductive isolation between species. Previously, we sequenced sperm lysin cDNAs from seven California abalone species and showed that positive Darwinian selection promotes their divergence. In this paper an additional 13 lysin sequences are presented representing species from Japan, Taiwan, Australia, New Zealand, South Africa, and Europe. The total of 20 sequences represents the most extensive analysis of a fertilization protein to date. The phylogenetic analysis divides the sequences into two major clades, one composed of species from the northern Pacific (California and Japan) and the other composed of species from other parts of the world. Analysis of nucleotide substitution demonstrates that positive selection is a general process in the evolution of this fertilization protein. Analysis of nucleotide and codon usage bias shows that neither parameter can account for the robust data supporting positive selection. The selection pressure responsible for the positive selection on lysin remains unknown.