Mitochondrial DNA and bindin gene sequence evolution among allopatric species of the sea urchin genus Arbacia.
Mitochondrial DNA and bindin gene sequence evolution among allopatric species of the sea urchin genus Arbacia.
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海胆属异域物种的线粒体 DNA 和结合蛋白基因序列进化。
DOI：
10.1093/oxfordjournals.molbev.a025914
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发表时间：
1998
影响因子：
10.7
通讯作者：
Vacquier,VD
中科院分区：
文献类型：
--
作者：
Metz,EC;Gómez-Gutiérrez,G;Vacquier,VD
Arbacia属的海胆(Stirodonta目)在数千公里的范围内具有不连续的异位分布。利用线粒体DNA(MtDNA)序列对四种Arbacia及其地理种群的系统发育关系进行了重建。几乎没有证据表明物种内种群的遗传结构，除了在两个极端范围的情况下。种间线粒体DNA序列的差异表明，分化发生在4-9个MYA左右。获得了编码精子蛋白Bindin及其内含子的基因序列，并与mtDNA系统发育进行了比较。在研究得很好的海胆中，卡马齿目海胆的mtDNA差异程度与Arbacia物种相似，已知在结合蛋白方面有显著差异。然而，在Arbacia中，Bindin的推导氨基酸序列几乎没有变化，这表明纯化选择对蛋白质起作用。相反，结合内含子序列表现出很大的差异性，包括大量的插入/缺失。在来自大西洋和太平洋的一对不同的Arbacia物种之间进行的受精实验表明，没有证据表明配子识别受阻。在Arbacia中，受精特异性的进化可能相对缓慢，这是由于物种内广泛的基因流动，对结合多肽的更大功能限制，或者在单一出现的物种中物种识别的选择压力降低。
Sea urchins of the genus Arbacia (order Stirodonta) have discontinuous allopatric distributions ranging over thousands of kilometers. Mitochondrial DNA (mtDNA) sequences were used to reconstruct phylogenetic relationships of four Arbacia species and their geographic populations. There is little evidence of genetic structuring of populations within species, except in two cases at range extremes. The mtDNA sequence differentiation between species suggests that divergence occurred about 4-9 MYA. Gene sequences encoding the sperm protein bindin and its intron were obtained and compared with the mtDNA phylogeny. Sea urchins among the well-studied echinoid order Camarodonta, with degrees of mtDNA divergence similar to those of Arbacia species, are known to have remarkable variation in bindin. However, in Arbacia, little variation in deduced amino acid sequences of bindin was found, indicating that purifying selection acts on the protein. In contrast, bindin intron sequences showed much differentiation, including numerous insertion/deletions. Fertilization experiments performed between a divergent pair of Arbacia species from the Atlantic and Pacific Oceans revealed no evidence of blocks to gamete recognition. In Arbacia, fertilization specificities may have evolved relatively slowly as a result of extensive gene flow within species, greater functional constraint on the bindin polypeptide, or reduced selective pressure for species recognition in singly occurring species.