Thind Amarinder Singh, Vitali Valerio, Guarracino Mario Rosario, Catania Francesco
Institute for High Performance Computing and Networking (ICAR), National Research Council (CNR), Naples, Italy.
Institute for Evolution and Biodiversity, Department of Biology, University of Münster, Germany.
Genome Biol Evol. 2020 May 1;12(5):626-638. doi: 10.1093/gbe/evaa052.
The pervasiveness of sex despite its well-known costs is a long-standing puzzle in evolutionary biology. Current explanations for the success of sex in nature largely rely on the adaptive significance of the new or rare genotypes that sex may generate. Less explored is the possibility that sex-underlying molecular mechanisms can enhance fitness and convey benefits to the individuals that bear the immediate costs of sex. Here, we show that the molecular environment associated with self-fertilization can increase stress resistance in the ciliate Paramecium tetraurelia. This advantage is independent of new genetic variation, coupled with a reduced nutritional input, and offers fresh insights into the mechanistic origin of sex. In addition to providing evidence that the molecular underpinnings of sexual reproduction and the stress response are linked in P. tetraurelia, these findings supply an integrative explanation for the persistence of self-fertilization in this ciliate.
尽管有众所周知的代价，但有性生殖的普遍性却是进化生物学中长期存在的谜题。目前对于有性生殖在自然界成功的解释很大程度上依赖于有性生殖可能产生的新的或罕见基因型的适应性意义。较少被探讨的一种可能性是，作为有性生殖基础的分子机制能够提高适应性，并为承担有性生殖直接代价的个体带来益处。在此，我们表明与自体受精相关的分子环境能够增强纤毛虫四膜虫的抗逆性。这一优势独立于新的遗传变异，同时伴随着营养输入的减少，并为有性生殖的机制起源提供了新的见解。除了提供证据表明四膜虫中有性生殖的分子基础与应激反应相关联之外，这些发现还为这种纤毛虫中自体受精的持续存在提供了一个综合性的解释。
