Experimental Evidence That Metamorphosis Alleviates Genomic Conflict
Experimental Evidence That Metamorphosis Alleviates Genomic Conflict
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DOI：
10.1086/704183
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发表时间：
2019-09-01
影响因子：
2.9
通讯作者：
Calsbeek, Ryan
中科院分区：
文献类型：
--
作者：
Goedert, Debora;Calsbeek, Ryan
每当遗传相关性状经历对抗性选择时，一个性状的适应反应可能导致相关性状的不适应反应。这是基因组水平冲突的一种形式，它可以通过阻碍生物体达到最佳适应性而产生重要的进化后果。在具有复杂生命史的生物体中，拮抗选择应该是普遍存在的，因为幼虫和成虫的生命阶段专门在截然不同的环境中生存。由于个体表达来自单一基因组的幼虫和成虫形态，个体发生阶段的基因组冲突也应该是普遍存在的。以林蛙为研究对象，研究了林蛙幼虫和变质后阶段的自然选择，并估计了各性状间的遗传相关性。不同的生命阶段经历了对抗性和一致性生存力选择的混合。性状之间的整合在变态过程中发生了变化，减少了导致冲突的遗传相关性。我们的研究结果提供了新的实验证据，证明变态可以通过将生活史阶段划分为更容易对选择做出反应的模块来缓解基因组冲突。这些结果突出了变态作为一种避免生态专业化权衡的手段的适应潜力。此外，它们提供了对复杂生命周期的流行和进化维持的见解。
Whenever genetically correlated traits experience antagonistic selection, an adaptive response in one trait can lead to a maladaptive response in the correlated trait. This is a form of genome-level conflict that can have important evolutionary consequences by impeding organisms from reaching their adaptive optima. Antagonistic selection should be pervasive in organisms with complex life histories because larval and adult life stages specialize in dramatically different environments. Since individuals express larval and adult morphologies from a single genome, genomic conflict across ontogenetic stages should also be prevalent. Using wood frogs as a study system, we measured natural selection on larval and postmetamorphic life stages and estimated genetic correlations among traits. Alternative life stages experienced a mix of both antagonistic and congruent viability selection. The integration between traits changed over the course of metamorphosis, reducing genetic correlations that cause conflict. Our results provide novel experimental evidence that metamorphosis can alleviate genomic conflict by partitioning life-history stages into modules that can more readily respond to selection. These results highlight the adaptive potential of metamorphosis as a means to avoid ecological specialization trade-offs. Moreover, they provide insights into the prevalence and evolutionary maintenance of complex life cycles.