School of Biological Sciences, University of Aberdeen, Aberdeen, UK.
Institute of Mathematics, University of Aberdeen, Aberdeen, UK.
Neotrop Entomol. 2022 Aug;51(4):526-535. doi: 10.1007/s13744-022-00976-5. Epub 2022 Jul 5.
Ecological conditions shape (adaptive) responses at the molecular, anatomical, and behavioral levels. Understanding these responses is key to predict the outcomes of intra- and inter-specific competitions and the evolutionary trajectory of populations. Recent technological advances have enabled large-scale molecular (e.g., RNAseq) and behavioral (e.g., computer vision) studies, but the study of anatomical responses to ecological conditions has lagged behind. Here, we highlight the role of X-ray micro-computed tomography (micro-CT) in generating in vivo and ex vivo 3D imaging of anatomical structures, which can enable insights into adaptive anatomical responses to ecological environments. To demonstrate the application of this method, we manipulated the larval density of Drosophila melanogaster Meigen flies and applied micro-CT to investigate the anatomical responses of the male reproductive organs to varying intraspecific competition levels during development. Our data is suggestive of two classes of anatomical responses which broadly agree with sexual selection theory: increasing larval density led to testes and ejaculatory duct to be overall larger (in volume), while the volume of accessory glands and, to a lesser extent, ejaculatory duct decreased. These two distinct classes of anatomical responses might reflect shared developmental regulation of the structures of the male reproductive system. Overall, we show that micro-CT can be an important tool to advance the study of anatomical (adaptive) responses to ecological environments.
生态条件在分子、解剖和行为水平上塑造（适应性）反应。了解这些反应是预测种内和种间竞争结果以及种群进化轨迹的关键。最近的技术进步使大规模的分子（例如 RNAseq）和行为（例如计算机视觉）研究成为可能，但对生态条件下解剖反应的研究却落后了。在这里，我们强调 X 射线微计算机断层扫描（micro-CT）在生成解剖结构的体内和离体 3D 成像中的作用，这可以深入了解对生态环境的适应性解剖反应。为了演示该方法的应用，我们操纵了黑腹果蝇幼虫的密度，并应用 micro-CT 研究了雄性生殖器官在发育过程中对不同种内竞争水平的解剖反应。我们的数据表明存在两种解剖反应类别，这些类别与性选择理论基本一致：幼虫密度增加导致睾丸和射精管的总体体积增大，而附属腺的体积以及射精管的体积在较小程度上减小。这两种不同的解剖反应类别可能反映了雄性生殖系统结构的共同发育调节。总的来说，我们表明 micro-CT 可以成为推进对生态环境的解剖（适应性）反应研究的重要工具。
