Wang Qi, Dicke Marcel, Haverkamp Alexander
Laboratory of Entomology, Wageningen University and Research, Wageningen, Netherlands.
Front Cell Neurosci. 2023 May 11;17:1155405. doi: 10.3389/fncel.2023.1155405. eCollection 2023.
Sensory processes have often been argued to play a central role in the selection of ecological niches and in the formation of new species. Butterflies are among the best studied animal groups with regards to their evolutionary and behavioral ecology and thereby offer an attractive system to investigate the role of chemosensory genes in sympatric speciation. We focus on two butterflies with overlapping host-plant ranges: and . Host-plant choice in lepidopterans is largely based on their olfactory and gustatory senses. Although the chemosensory responses of the two species have been well characterized at the behavioral and physiological levels, little is known about their chemoreceptor genes. Here, we compared the chemosensory genes of and to investigate whether differences in these genes might have contributed to their evolutionary separation. We identified a total of 130 and 122 chemoreceptor genes in the genome and antennal transcriptome, respectively. Similarly, 133 and 124 chemoreceptors were identified in the genome and antennal transcriptome. We found some chemoreceptors being differentially expressed in the antennal transcriptomes of the two species. The motifs and gene structures of chemoreceptors were compared between the two species. We show that paralogs share conserved motifs and orthologs have similar gene structures. Our study therefore found surprisingly few differences in the numbers, sequence identities and gene structures between the two species, indicating that the ecological differences between these two butterflies might be more related to a quantitative shift in the expression of orthologous genes than to the evolution of novel receptors as has been found in other insects. Our molecular data supplement the wealth of behavioral and ecological studies on these two species and will thereby help to better understand the role of chemoreceptor genes in the evolution of lepidopterans.
感觉过程通常被认为在生态位选择和新物种形成中起着核心作用。蝴蝶是进化和行为生态学方面研究得最好的动物群体之一，因此为研究化学感应基因在同域物种形成中的作用提供了一个有吸引力的系统。我们关注两种寄主植物范围重叠的蝴蝶：[此处原文缺失两种蝴蝶的具体名称]。鳞翅目昆虫对寄主植物的选择很大程度上基于它们的嗅觉和味觉。尽管这两个物种的化学感应反应在行为和生理水平上已经得到了很好的表征，但对它们的化学感受器基因却知之甚少。在这里，我们比较了[此处原文缺失两种蝴蝶的具体名称]的化学感应基因，以研究这些基因的差异是否可能导致了它们的进化分离。我们分别在[此处原文缺失一种蝴蝶的具体名称]的基因组和触角转录组中鉴定出总共130个和122个化学感受器基因。同样，在[此处原文缺失另一种蝴蝶的具体名称]的基因组和触角转录组中鉴定出133个和124个化学感受器。我们发现一些化学感受器在这两个物种的触角转录组中差异表达。比较了这两个物种化学感受器的基序和基因结构。我们表明，旁系同源物共享保守基序，直系同源物具有相似的基因结构。因此，我们的研究发现这两个物种在数量、序列同一性和基因结构上惊人地少有差异，这表明这两种蝴蝶之间的生态差异可能更多地与直系同源基因表达的定量变化有关，而不是像在其他昆虫中发现的那样与新受体的进化有关。我们的分子数据补充了关于这两个物种丰富的行为和生态学研究，从而将有助于更好地理解化学感受器基因在鳞翅目进化中的作用。
