Data from: Self-recognition in crickets via on-line processing

Self-referent phenotype matching, the ability of animals to use aspects of their own phenotype as a referent in discrimination decisions, is believed to play a significant role in nepotistic interactions and mate choice in a wide range of taxa [1]. An individual’s ability to assess the similarity between its own phenotype and that of the individuals it encounters can provide a reliable measure of relatedness, thereby facilitating inbreeding avoidance, optimal outbreeding or altruistic behavior towards kin 2 and 3. Although self-referencing is believed to be widespread, definitive evidence is scarce and its role in recognition controversial, in part, because of the difficulty in ruling out early exposure to close kin and the possibility that individuals imprint on maternal cues early in their ontogeny, either during birth or via cues encountered upon hatching from eggs 1 and 4. An equally important, yet unanswered question is whether individuals that perform self-referencing imprint on their own traits at an early stage, relying on this memorized template in subsequent interactions, or whether no memory is formed but individuals use their own phenotype directly in comparison with other individuals (i.e., ‘on-line processing’) [3]. Finally, animals may possess ‘recognition alleles’, in which both the phenotypic cues and the knowledge of the cues have a genetic basis [5]. Here we show in the decorated cricket, Gryllodes sigillatus, that female mate choice can be manipulated by experimentally altering a female’s own olfactory cues. We found exclusive evidence both for the existence of a chemosensory self-referencing mechanism and that females do not rely on an innate or early learned template but rather directly use their own phenotypic cues in comparison.

自我参照表型匹配（Self-referent phenotype matching）指动物将自身表型特征作为参照用于判别决策的能力，被认为在诸多分类群的亲缘偏袒互动与择偶选择中发挥重要作用[1]。个体评估自身表型与偶遇个体表型间相似性的能力，可作为可靠的亲缘关系衡量指标，进而助力近交回避、最优远交或针对亲属的利他行为[2,3]。尽管学界普遍认为自我参照机制广泛存在，但确凿证据仍较为匮乏，且其在识别过程中的作用颇具争议，部分原因在于难以排除早期接触近亲的影响，以及个体可能在个体发育早期（如出生时或从卵中孵化后接触相关线索）通过母体线索形成印记[1,4]。另一个同等重要却尚未解答的问题是：进行自我参照的个体究竟是在早期阶段就对自身性状形成印记，并在后续互动中依赖该记忆模板，还是并未形成记忆，而是直接将自身表型与其他个体进行比较（即“在线加工”）[3]。最后，动物可能拥有“识别等位基因（recognition alleles）”，即表型线索与线索认知均具有遗传基础[5]。本研究以装饰蟋蟀（Gryllodes sigillatus）为研究对象，证实可通过实验改变雌性的嗅觉线索来操控其择偶选择。研究结果提供了排他性证据，既证明了化学感应自我参照机制的存在，也表明雌性并非依赖先天或早期习得的模板，而是直接以自身表型特征作为比较依据。