Occasional males in parthenogenetic populations of Asobara japonica (Hymenoptera: Braconidae): low Wolbachia titer or incomplete coadaptation?
Occasional males in parthenogenetic populations of Asobara japonica (Hymenoptera: Braconidae): low Wolbachia titer or incomplete coadaptation?
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DOI：
10.1038/hdy.2011.82
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发表时间：
2012-03-01
期刊：
影响因子：
3.8
通讯作者：
Kraaijeveld, K.
中科院分区：
文献类型：
--
作者：
Reumer, B. M.;van Alphen, J. J. M.;Kraaijeveld, K.
沃尔巴克氏体是一种内共生细菌，可以操纵宿主的繁殖。一些种群的寄生蜂Asobara japonica感染Wolbachia并进行单性生殖，而其他种群则没有感染并进行有性生殖。沃尔巴克氏体感染A.雌性粳稻有规律地产生少量雄性后代。由于该领域的所有女性都被感染，感染的女性不能进行有性生殖，男性生产似乎是不适应的。我们调查了为什么这些雌性仍然产生雄性。我们测试了三个假设：较高的饲养温度可能导致较高的后代性别比（更多的雄性），母亲的低沃尔巴克氏体滴度可能导致较高的后代性别比和/或沃尔巴克氏体感染是相对较新的起源，并且没有足够的时间过去以允许沃尔巴克氏体和宿主之间的完全共适应。总的来说，33%的沃尔巴克氏体感染的女性产生了男性，其中56%的男性也感染了沃尔巴克氏体。无论是后代的性别比例，也没有男性感染频率显着影响饲养温度或沃尔巴克氏体浓度的母亲。其中一个未感染人群的线粒体DNA序列与两个感染人群的相同。因此，A.日本应该是最近才出现的。感染人群中的线粒体序列变异表明，沃尔巴克氏体通过宿主人群的传播涉及水平传播。我们的结论是，偶尔的男性生产沃尔巴克氏体感染的女性是最有可能的适应不良的副作用，共生体和主机之间的不完整的共同进化，在这个相对年轻的感染。Heredity（2012）108，341-346; doi：10.1038/hdy.2011.82; 2011年9月21日在线发表
Wolbachia are endosymbiotic bacteria known to manipulate the reproduction of their hosts. Some populations of the parasitoid wasp Asobara japonica are infected with Wolbachia and reproduce parthenogenetically, while other populations are not infected and reproduce sexually. Wolbachia-infected A. japonica females regularly produce small numbers of male offspring. Because all females in the field are infected and infected females are not capable of sexual reproduction, male production seems to be maladaptive. We investigated why these females nevertheless produce males. We tested three hypotheses: high rearing temperatures could result in higher offspring sex ratios (more males), low Wolbachia titer of the mother could lead to higher offspring sex ratios and/or the Wolbachia infection is of relatively recent origin and not enough time has passed to allow complete coadaptation between Wolbachia and host. In all, 33% of the Wolbachia-infected females produced males and 56% of these males were also infected with Wolbachia. Neither offspring sex ratio nor male infection frequency was significantly affected by rearing temperature or Wolbachia concentration of the mother. The mitochondrial DNA sequence of one of the uninfected populations was identical to that of two of the infected populations. Therefore, the initial Wolbachia infection of A. japonica must have occurred recently. Mitochondrial sequence variation among the infected populations suggests that the spread of Wolbachia through the host populations involved horizontal transmission. We conclude that the occasional male production by Wolbachia-infected females is most likely a maladaptive side effect of incomplete coevolution between symbiont and host in this relatively young infection. Heredity (2012) 108, 341-346; doi:10.1038/hdy.2011.82; published online 21 September 2011