Extreme developmental instability is associated with the pea aphid wing plasticity

A key focus of evolutionary developmental biology is on how phenotypic diversity is generated. In particular, both plasticity and developmental instability can contribute to phenotypic variation among genetically identical individuals, but the interactions between the two phenomena and their general fitness impacts are unclear. We discovered a striking example of asymmetry in pea aphids: the presence of wings on one side and the complete or partial absence of wings on the opposite side. We used this asymmetric phenotype to study the connection between plasticity, developmental instability, and fitness. We found that this asymmetry equally affects both sides and thus is a developmental instability; is present in some genetically unique lines but not others and thus has a genetic basis; and has intermediate levels of fecundity, and thus does not necessarily have negative fitness consequences. We conclude that this dramatic asymmetry may arise from incomplete switching between developmenta...进化发育生物学（Evolutionary Developmental Biology）的核心研究焦点之一，是探究表型多样性（Phenotypic Diversity）的产生机制。具体而言，表型可塑性（Phenotypic Plasticity）与发育不稳定性（Developmental Instability）均可导致基因完全相同的个体间出现表型变异，但二者之间的相互作用及其对适合度（Fitness）的普遍影响尚未明确。 我们在豌豆蚜（Pea Aphids）中发现了一例极为显著的不对称表型（Asymmetric Phenotype）：个体一侧生长出翅膀，而对侧则完全或部分缺失翅膀。我们借助这一不对称表型，探究了表型可塑性、发育不稳定性与适合度之间的关联。 研究发现，该不对称现象对两侧的影响程度均等，因此属于发育不稳定性；该现象仅存在于部分遗传独特的品系中，而非全部品系，因此具有遗传基础；其繁殖力（Fecundity）处于中等水平，因此未必会带来适合度方面的负面影响。 我们据此推断，这种显著的不对称现象可能源于发育相关通路间的不完全切换（原文此处为developmenta，未完整）。