Burdine Levi W, Moczek Armin P, Rohner Patrick T
Department of Biology Indiana University Bloomington Bloomington Indiana USA.
Department of Ecology, Behavior, and Evolution University of California San Diego La Jolla California USA.
Ecol Evol. 2024 Mar 10;14(3):e11089. doi: 10.1002/ece3.11089. eCollection 2024 Mar.
Many symbionts are sexually transmitted and impact their host's development, ecology, and evolution. While the significance of symbionts that cause sexually transmitted diseases (STDs) is relatively well understood, the prevalence and potential significance of the sexual transmission of mutualists remain elusive. Here, we study the effects of sexually transmitted mutualist nematodes on their dung beetle hosts. Symbiotic nematodes are present on the genitalia of male and female beetles and are horizontally transmitted during mating and vertically passed on to offspring during oviposition. A previous study indicates that the presence of nematodes benefits larval development and life history in a single host species, . However, nematodes can be found in association with a variety of beetle species. Here, we replicate these previous experiments, assess whether the beneficial effects extend to other host species, and test whether nematode-mediated effects differ between male and female host beetles. Rearing three relatively distantly related dung beetle species with and without nematodes, we find that the presence of nematodes benefits body size, but not development time or survival across all three species. Likewise, we found no difference in the benefit of nematodes to male compared to female beetles. These findings highlight the role of sexually transmitted mutualists in the evolution and ecology of dung beetles.
许多共生体通过性传播，并影响其宿主的发育、生态和进化。虽然人们对引起性传播疾病（STD）的共生体的重要性相对了解较多，但互利共生体性传播的发生率和潜在重要性仍然难以捉摸。在这里，我们研究性传播的互利共生线虫对其蜣螂宿主的影响。共生线虫存在于雄性和雌性甲虫的生殖器上，在交配过程中水平传播，并在产卵过程中垂直传递给后代。先前的一项研究表明，线虫的存在有利于单一宿主物种的幼虫发育和生活史。然而，线虫可以在多种甲虫物种中发现。在这里，我们重复这些先前的实验，评估这种有益影响是否扩展到其他宿主物种，并测试线虫介导的影响在雄性和雌性宿主甲虫之间是否存在差异。我们饲养了三种亲缘关系相对较远的蜣螂物种，分别有无线虫，发现线虫的存在有利于体型大小，但对所有三个物种的发育时间或存活率没有影响。同样，我们发现线虫对雄性甲虫和雌性甲虫的益处没有差异。这些发现突出了性传播互利共生体在蜣螂进化和生态中的作用。
