Nieuwenhuis Bart P S, Immler Simone
Department of Evolutionary Biology, Uppsala University, Uppsala, Sweden.
Bioessays. 2016 Nov;38(11):1141-1149. doi: 10.1002/bies.201600139. Epub 2016 Sep 21.
Alternative ways to ensure mate compatibility, such as hermaphroditism and the breakdown of self-incompatibility, evolved repeatedly when finding a mating partner is difficult. In a variety of microorganisms where compatibility is determined by mating-types, a highly regulated form of universal compatibility system called mating-type switching has evolved several times. This sophisticated system allows for the genetic adjustment of the mating type during asexual growth, and it most likely evolved for reproductive assurance of immotile species under low densities. In this review, we compare the switching strategy to other universal compatibility systems such as "unisexual mating" and homothallism. We identify the costs of switching, including genome instability, and mechanistic costs, as well as the benefits, mainly the maintenance of important mating-type functions. Given the potential benefits of mating-type switching, we speculate that switching is likely to have evolved many times independently, and may be more common in groups where genetic mating types regulate mate compatibility than assumed so far.
当寻找交配伙伴困难时，确保配偶兼容性的其他方式，如雌雄同体和自交不亲和性的打破，会反复进化。在多种由交配型决定兼容性的微生物中，一种高度调控的通用兼容性系统，即交配型转换，已经多次进化。这种复杂的系统允许在无性生长过程中对交配型进行遗传调整，它很可能是为了确保低密度下不能移动的物种的繁殖而进化的。在这篇综述中，我们将这种转换策略与其他通用兼容性系统，如“单性交配”和同宗配合进行比较。我们确定了转换的成本，包括基因组不稳定性和机制成本，以及好处，主要是维持重要的交配型功能。鉴于交配型转换的潜在好处，我们推测转换可能已经多次独立进化，并且在遗传交配型调节配偶兼容性的群体中可能比目前所认为的更为普遍。
