No evidence for an intragenomic arms race under paternal genome elimination in Planococcus mealybugs
No evidence for an intragenomic arms race under paternal genome elimination in Planococcus mealybugs
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DOI：
10.1111/jeb.13431
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发表时间：
2019-05-01
影响因子：
2.1
通讯作者：
Ross, Laura
中科院分区：
文献类型：
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作者：
de la Filia, Andres G.;Fenn-Moltu, Gyda;Ross, Laura
生殖过程中产生的基因组冲突可能在塑造整个生命中惊人的多样性生殖策略中发挥重要作用。其中之一是父本基因组消除（PGE），一种在节肢动物中独立进化多次的单倍性形式。PGE男性是二倍体，但只传递母系遗传的染色体，而父系同源物被排除在精子之外。因此，母亲有效地垄断了儿子的亲子关系，而父亲的生育成功则成为了代价。这在两性之间造成了惊人的冲突，可能导致父方和母方基因组在基因传递方面的共同进化军备竞赛，但在PGE下确实发生了这种军备竞赛的经验证据很少。本研究解决了这一问题，通过测试是否PGE是完整的，当父亲的基因型暴露于不同的母体背景在种内和杂交的柑橘粉蚧，柑橘动球菌，和密切相关的榕树动球菌。我们确定男性是否可以通过他们的儿子传递遗传信息，通过跟踪三代系谱中的两个特征的遗传：微卫星标记和性别特异性信息素偏好。我们的研究结果表明，通过男性发生在一个低频率的单父染色体泄漏，但我们没有发现证据的父亲信息素的偏好从父亲到儿子的传输。杂交和种内杂交的父等位基因的泄漏率之间的差异的情况下，表明共同进化的军备竞赛不能证明在这个进化的时间尺度，但我们的结论是，有范围内的父母基因组之间的冲突粉蚧。最后，我们将讨论这些父亲逃脱如何发生，以及这些发现可能揭示这个奇怪的遗传系统的进化动力学。
Genomic conflicts arising during reproduction might play an important role in shaping the striking diversity of reproductive strategies across life. Among these is paternal genome elimination (PGE), a form of haplodiploidy which has independently evolved several times in arthropods. PGE males are diploid but transmit maternally inherited chromosomes only, whereas paternal homologues are excluded from sperm. Mothers thereby effectively monopolize the parentage of sons, at the cost of the father's reproductive success. This creates striking conflict between the sexes that could result in a co-evolutionary arms race between paternal and maternal genomes over gene transmission, yet empirical evidence that such an arms race indeed takes place under PGE is scarce. This study addresses this by testing whether PGE is complete when paternal genotypes are exposed to divergent maternal backgrounds in intraspecific and hybrid crosses of the citrus mealybug, Planococcus citri, and the closely related Planococcus ficus. We determined whether males can transmit genetic information through their sons by tracking inheritance of two traits in a three-generation pedigree: microsatellite markers and sex-specific pheromone preferences. Our results suggest leakages of single paternal chromosomes through males occurring at a low frequency, but we find no evidence for transmission of paternal pheromone preferences from fathers to sons. The absence of differences between hybrid and intraspecific crosses in leakage rate of paternal alleles suggests that a co-evolutionary arms race cannot be demonstrated on this evolutionary timescale, but we conclude that there is scope for intragenomic conflict between parental genomes in mealybugs. Finally, we discuss how these paternal escapes can occur and what these findings may reveal about the evolutionary dynamics of this bizarre genetic system.