Multiple infections and diversity of cytoplasmic incompatibility in a haplodiploid species
Multiple infections and diversity of cytoplasmic incompatibility in a haplodiploid species
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DOI：
10.1038/sj.hdy.6800596
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发表时间：
2005-02-01
期刊：
影响因子：
3.8
通讯作者：
Vavre, F
中科院分区：
文献类型：
--
作者：
Mouton, L;Henri, H;Vavre, F
细胞质不亲和性（CI）是通常由细胞内共生细菌沃尔巴克氏体（Wolbachia）诱导的精子-卵子不亲和性，其在二倍体物种中导致胚胎死亡。在单倍二倍体物种中，根据不相容的受精卵是否发育成雄性（雄性发育（MD））或流产（雌性死亡（FM）），存在两种类型的CI。CI允许在宿主群体中维持多重感染，从而允许在共感染菌株之间发生相互作用。在异瘤细青霉中，三种沃尔巴克氏体菌株自然共存（wLhet 1、wLhet 2、wLhet 3）。当这三种菌株都存在时，它们诱导FM型CI，而wLhet 1单独表达MD和FM之间的CI表型。在这里，我们比较CI的影响，涉及昆虫线共享相同的核背景，但窝藏不同的混合物的菌株杂交。交配实验表明：（i）wLhet 2和wLhet 3在单独作用时也诱导中间CI，并显示双向不亲和性;（ii）在CI表达中共感染菌株之间不存在相互作用;（iii）存在于雄性宿主内的沃尔巴克氏体的多样性影响CI的表达：菌株数量的增加与MD型比例的降低相关，MD型比例的降低也与细菌密度的增加相关。这些结果表明，FM型的CI比MD型的CI具有更强的效应，这与传统的解释单倍二倍体CI多样性的假说相矛盾，并可能为昆虫CI机制的研究提供新的信息。
Cytoplasmic incompatibility (CI) is a sperm - egg incompatibility commonly induced by the intracellular endosymbiont bacterium Wolbachia that, in diploid species, results in embryo mortality. In haplodiploid species, two types of CI exist depending on whether the incompatible fertilized eggs develop into males ( male development ( MD)) or abort ( female mortality ( FM)). CI allows multiple infections to be maintained in host populations, and thus allows interactions to occur between co-infecting strains. In Leptopilina heterotoma, three Wolbachia strains coexist naturally (wLhet1, wLhet2, wLhet3). When these three strains are all present, they induce a CI of FM type, whereas wLhet1 alone expresses a CI phenotype intermediate between MD and FM. Here, we compare CI effects in crosses involving insect lines sharing the same nuclear background, but harboring different mixtures of strains. Mating experiments showed that: (i) wLhet2 and wLhet3 also induce an intermediate CI when acting alone, and show a bidirectional incompatibility; (ii) there is no interaction between the co-infecting strains in CI expression; (iii) the diversity of Wolbachia present within a male host influences the expression of CI: an increase in the number of strains is correlated with a decrease in the proportion of the MD type, which is also correlated with an increase in bacterial density. All these data suggest that the CI of FM type results from a stronger effect than the MD type, which conflicts with the conventional hypotheses used to explain CI diversity in haplodiploids, and could provide some new information about CI mechanisms in insects.