Shodja Donya N, Glassford William J, Rice Gavin, Smith Sarah J, Rebeiz Mark
Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Sci Adv. 2025 Jul 18;11(29):eadt7825. doi: 10.1126/sciadv.adt7825. Epub 2025 Jul 16.
The origin of morphological novelties has long fascinated biologists. Signaling pathways play important roles in the formation of novelties; however, the history of how they become integrated into new developmental programs remains unclear. Here, we investigated the evolution of the posterior lobe, a novel structure in the male genitalia of . We demonstrated that a Notch signaling center is required for the formation of this novelty and identified enhancers of the ligand , which allowed us to track the evolutionary history of this signaling center. Unexpectedly, we found that the posterior lobe signaling center emerged from a preexisting role in genital disc eversion. We provide a likely mechanism by which Delta contributes to genital eversion through a network of apical extracellular matrix, which also became integrated into the posterior lobe program. This work demonstrates that novelties may be formed in the context of already complex developmental processes, by appending new roles to preexisting signals.
形态新奇特征的起源长期以来一直吸引着生物学家。信号通路在新奇特征的形成中发挥着重要作用；然而，它们如何整合到新的发育程序中的历史仍不清楚。在这里，我们研究了后叶的进化，后叶是[物种名称]雄性生殖器中的一种新结构。我们证明了一个Notch信号中心是这个新奇特征形成所必需的，并鉴定了配体的增强子，这使我们能够追踪这个信号中心的进化历史。出乎意料的是，我们发现后叶信号中心源自生殖器盘外翻中预先存在的作用。我们提供了一种可能的机制，通过该机制Delta通过顶端细胞外基质网络促进生殖器外翻，该网络也整合到了后叶程序中。这项工作表明，新奇特征可能在已经复杂的发育过程中形成，通过为预先存在的信号附加新的作用。
