Genevcius Bruno C, Simon Monique N, Moraes Tamara, Schwertner Cristiano F
Museum of Zoology, Graduate Program in Systematics, Animal Taxonomy and Biodiversity, University of São Paulo, São Paulo, Brazil.
Current address: Department of Genetics and Evolutionary Biology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil.
Evolution. 2020 Jun;74(6):1048-1062. doi: 10.1111/evo.13977. Epub 2020 May 17.
Genitalia are multitasking structures whose development is mediated by numerous regulatory pathways. This multifactorial nature provides an avenue for multiple sources of selection. As a result, genitalia tend to evolve as modular systems comprising semi-independent subsets of structures, yet the processes that give rise to those patterns are still poorly understood. Here, we ask what are the relative roles of development and function in shaping modular patterns of genitalia within populations and across species of stink-bugs. We found that male genitalia are less integrated, more modular, and primarily shaped by functional demands. In contrast, females show higher integration, lower modularity, and a predominant role of developmental processes. Further, interactions among parts of each sex are more determinant to modularity than those between the sexes, and patterns of modularity are equivalent between and within species. Our results strongly indicate that genitalia have been subjected to sex-specific selection, although male and female genitalia are homologous and functionally associated. Moreover, modular patterns are seemingly constant in the evolutionary history of stink-bugs, suggesting a scenario of multivariate stabilizing selection within each sex. Our study demonstrates that interactions among genital parts of the same sex may be more fundamental to genital evolution than previously thought.
生殖器是具有多种功能的结构，其发育由众多调控途径介导。这种多因素性质为多种选择来源提供了一条途径。因此，生殖器倾向于作为由半独立结构子集组成的模块化系统进化，然而导致这些模式的过程仍知之甚少。在这里，我们探讨在蝽象种群内和跨物种中，发育和功能在塑造生殖器模块化模式方面的相对作用。我们发现雄性生殖器的整合程度较低、模块化程度更高，并且主要由功能需求塑造。相比之下，雌性表现出更高的整合度、更低的模块化程度，以及发育过程的主导作用。此外，每种性别的各部分之间的相互作用对模块化的决定性比两性之间的相互作用更大，并且模块化模式在物种间和物种内是等效的。我们的结果有力地表明，尽管雄性和雌性生殖器是同源的且在功能上相关联，但生殖器已受到性别特异性选择。此外，模块化模式在蝽象的进化历史中似乎是恒定的，这表明在每种性别内存在多变量稳定选择的情况。我们的研究表明，同性生殖器各部分之间的相互作用可能对生殖器进化比以前认为的更为重要。
