Shortlidge Erin E, Carey Sarah B, Payton Adam C, McDaniel Stuart F, Rosenstiel Todd N, Eppley Sarah M
Department of Biology, Portland State University, PO Box 751, Portland, OR 97202-0751, USA.
Department of Biology, University of Florida, PO Box 118525, Gainesville, FL 32611-8525, USA.
Proc Biol Sci. 2021 Mar 31;288(1947):20210119. doi: 10.1098/rspb.2021.0119.
The evolution of sustained plant-animal interactions depends critically upon genetic variation in the fitness benefits from the interaction. Genetic analyses of such interactions are limited to a few model systems, in part because genetic variation may be absent or the interacting species may be experimentally intractable. Here, we examine the role of sperm-dispersing microarthropods in shaping reproduction and genetic variation in mosses. We established experimental mesocosms with known moss genotypes and inferred the parents of progeny from mesocosms with and without microarthropods, using a pooled sequencing approach. Moss reproductive rates increased fivefold in the presence of microarthropods, relative to control mesocosms. Furthermore, the presence of microarthropods increased the total number of reproducing moss genotypes, and changed the rank-order of fitness of male and female moss genotypes. Interestingly, the genotypes that reproduced most frequently did not produce sporophytes with the most spores, highlighting the challenge of defining fitness in mosses. These results demonstrate that microarthropods provide a fitness benefit for mosses, and highlight the potential for biotic dispersal agents to alter fitness among moss genotypes.
植物与动物持续相互作用的进化关键取决于这种相互作用所带来的适应性益处的遗传变异。对此类相互作用的遗传分析仅限于少数几个模型系统，部分原因是可能不存在遗传变异，或者相互作用的物种在实验上难以处理。在这里，我们研究了传播精子的微型节肢动物在塑造苔藓繁殖和遗传变异方面的作用。我们建立了具有已知苔藓基因型的实验性中型生态系统，并使用混合测序方法从有微型节肢动物和没有微型节肢动物的中型生态系统中推断后代的亲本。与对照中型生态系统相比，在有微型节肢动物的情况下，苔藓繁殖率提高了五倍。此外，微型节肢动物的存在增加了有繁殖能力的苔藓基因型的总数，并改变了雄性和雌性苔藓基因型的适应性排名顺序。有趣的是，繁殖最频繁的基因型并没有产生孢子最多的孢子体，这凸显了定义苔藓适应性的挑战。这些结果表明，微型节肢动物为苔藓提供了适应性益处，并突出了生物传播媒介改变苔藓基因型适应性的潜力。
