Body size as a magic trait in two plant-feeding insect species
Body size as a magic trait in two plant-feeding insect species
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DOI：
10.1101/2022.10.11.511791
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发表时间：
2022-10
期刊：
影响因子：
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通讯作者：
Ashleigh N. Glover;E. Bendall;J. W. Terbot;Nicole Payne;Avery Webb;Ashley Filbeck;Gavin Norman;C. Linnen
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文献类型：
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作者：
Ashleigh N. Glover;E. Bendall;J. W. Terbot;Nicole Payne;Avery Webb;Ashley Filbeck;Gavin Norman;C. Linnen
当基因流伴随着物种形成时，重组可以使分歧选择的基因座和赋予生殖隔离的基因座分离。当竞争性交配和破坏性选择涉及相同的“神奇”特征时，这种同域分化的障碍就消失了。虽然魔法特征可能很普遍，但不同类型的魔法特征对物种形成的相对重要性仍然不清楚。由于身体大小经常有助于主机的适应性和植物饲养的昆虫的交配，我们评估了几个神奇的性状预测这个特性在一对同域的Neodiprion叶蜂物种适应不同的松树主机。一个大型的形态数据集显示，使用粗针松的种群和物种的叶蜂成虫始终大于使用细针松的。重组回交雌性的适合度数据显示，卵大小是在不同的选择之间的首选松树。最后，交配试验显示，在三个不同的杂交种内和种间的强大的大小-rectative交配，最强的前合子隔离种群之间具有最大的种间大小差异。总之，我们的数据支持身体大小作为松叶蜂和可能许多其他植物饲养昆虫的神奇特征。我们的工作也证明了种内形态和生态的变异如何导致前合子隔离强度的地理变异。
When gene flow accompanies speciation, recombination can decouple divergently selected loci and loci conferring reproductive isolation. This barrier to sympatric divergence disappears when assortative mating and disruptive selection involve the same “magic” trait. Although magic traits could be widespread, the relative importance of different types of magic traits to speciation remains unclear. Because body size frequently contributes to host adaptation and assortative mating in plant-feeding insects, we evaluated several magic trait predictions for this trait in a pair of sympatric Neodiprion sawfly species adapted to different pine hosts. A large morphological dataset revealed that sawfly adults from populations and species that use thicker-needled pines are consistently larger than those that use thinner needled-pines. Fitness data from recombinant backcross females revealed that egg size is under divergent selection between the preferred pines. Lastly, mating assays revealed strong size-assortative mating within and between species in three different crosses, with the strongest prezygotic isolation between populations that have the greatest interspecific size differences. Together, our data support body size as a magic trait in pine sawflies and possibly many other plant-feeding insects. Our work also demonstrates how intraspecific variation in morphology and ecology can cause geographic variation in the strength of prezygotic isolation.