Disentangling the effects of mating systems and mutation rates on cytoplamic diversity in gynodioecious Silene nutans and dioecious Silene otites
Disentangling the effects of mating systems and mutation rates on cytoplamic diversity in gynodioecious Silene nutans and dioecious Silene otites
复制标题
解开交配系统和突变率对雌雄异株 Silene nutans 和雌雄异株 Silene otites 细胞质多样性的影响
作者：
E. Lahiani;M. Dufay;Vincent Castric;S. Cadre;Deborah Charlesworth;F. Rossum;Pascal Touzet
许多开花植物物种表现出各种不同的性别变体，最常见的两种情况是雌性和雄性（雌雄异株）或雌雄同体和雌性（雌雄异株）。在这项研究中，我们比较了DNA序列的变异性的三个基因组（核，线粒体和叶绿体）的一个雌雄异株的物种，垂穗蝇子草，与一个密切相关的雌雄异株的物种，蝇子草otites。在理论模型的光，我们预计细胞质多样性不同的两个物种之间的选择动力学，作用于细胞质基因组在gynodioecious物种：在流行病的情况下，gynodioecious物种预计表现出较低的细胞质多样性比雌雄异株的物种，而相反的情况下，预计在平衡选择保持不育的gynodioecious物种的细胞质。我们发现，在核基因多样性方面，种间没有差异，但在细胞质基因座方面，雌株异株的S。nutans比雌雄异株的S. otites，即使后者具有相对高的线粒体同义替换率，因此推测具有更高的突变率。因此，由于线粒体突变率不能解释S. nutans，我们的研究结果支持的假设，gynodiopathy在S。nutans一直保持平衡选择，而不是由类似的动力学。
Many flowering plant species exhibit a variety of distinct sexual morphs, the two most common cases being the co-occurrence of females and males (dioecy) or the co-occurrence of hermaphrodites and females (gynodioecy). In this study, we compared DNA sequence variability of the three genomes (nuclear, mitochondrial and chloroplastic) of a gynodioecious species, Silene nutans, with that of a closely related dioecious species, Silene otites. In the light of theoretical models, we expect cytoplasmic diversity to differ between the two species due to the selective dynamics that acts on cytoplasmic genomes in gynodioecious species: under an epidemic scenario, the gynodioecious species is expected to exhibit lower cytoplasmic diversity than the dioecious species, while the opposite is expected in the case of balancing selection maintaining sterility cytoplasms in the gynodioecious species. We found no difference between the species for nuclear gene diversity, but, for the cytoplasmic loci, the gynodioecious S. nutans had more haplotypes, and higher nucleotide diversity, than the dioecious relative, S. otites, even though the latter has a relatively high rate of mitochondrial synonymous substitutions, and therefore presumably a higher mutation rate. Therefore, as the mitochondrial mutation rate cannot account for the higher cytoplasmic diversity found in S. nutans, our findings support the hypothesis that gynodioecy in S. nutans has been maintained by balancing selection rather than by epidemic-like dynamics.
DOI：
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发表时间：
2002
影响因子：
11.1
作者：
K. Adams
通讯作者：
K. Adams
影响因子：
14.9
作者：
MOHR, G;PERLMAN, PS;LAMBOWITZ, AM
通讯作者：
LAMBOWITZ, AM