Molecular markers indicate rare sex in a predominantly asexual parasitoid wasp
Molecular markers indicate rare sex in a predominantly asexual parasitoid wasp
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DOI：
10.2307/2640822
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发表时间：
1999-08-01
期刊：
影响因子：
3.3
通讯作者：
Godfray, HCJ
中科院分区：
文献类型：
--
作者：
Belshaw, R;Quicke, DLJ;Godfray, HCJ
寄生蜂属Lysiphlebus（Hyplutera：Braconidae：Aphidiinae）包含一个分类学上难以分辨的有性种和无性种克隆群。最大简约法和最大似然分析的线粒体DNA序列数据从标本收集在西欧表明，无性，这似乎不是由细菌沃尔巴克氏体，是集中在两个地理分布广泛的谱系，其中较老的分歧从最接近的现存的有性类群约0.5百万年前。然而，一个核内含子（延伸因子-1 α）的DNA序列没有显示出与这种模式的一致性，和一个非常高的等位基因多样性的杂合子的频率高得多的频率之间观察到的无性繁殖的女性相比，从有性物种的女性。这种模式与母系遗传的无性恋相一致，再加上与几个密切相关的有性群体或物种的成员发生过罕见的性行为。我们的观察加强了最近的论点，罕见的性别可能是更重要的持续性，否则无性系比迄今为止赞赏。
The parasitoid wasp genus Lysiphlebus (Hymenoptera: Braconidae: Aphidiinae) contains a taxonomically poorly resolved group of both sexual (arrhenotokous) species and asexual (thelytokous) clones. Maximum-parsimony and maximum-likelihood analyses of mitochondrial DNA sequence data from specimens collected across Western Europe showed that asexuality, which does not appear to be caused by the bacterium Wolbachia, is concentrated in two geographically widespread lineages, the older of which diverged from the closest extant sexual taxa approximately 0.5 million years ago. However, the DNA sequences of a nuclear intron (elongation factor-1 alpha) showed no congruence with this pattern, and a much higher frequency of heterozygotes with very high allelic diversity was observed among the asexual females compared to that among females from the sexual species. This pattern is consistent with maternally inherited asexuality coupled with a history of rare sex with members of several closely related sexual populations or species. Our observations reinforce recent arguments that rare sex may be more important for the persistence of otherwise asexual lineages than hitherto appreciated.