Department of Zoology, University of Cambridge, Cambridge, UK.
Kalahari Research Centre, Kuruman River Reserve, Northern Cape, South Africa.
Proc Biol Sci. 2024 Oct;291(2033):20241138. doi: 10.1098/rspb.2024.1138. Epub 2024 Oct 16.
Across taxa, breeding among close relatives is usually avoided because it incurs fitness costs to offspring. Incest is often averted through the dispersal of either sex from the natal area to breed. In some philopatric species, association among relatives extends into adulthood, and an ability to discriminate kin may be required for individuals to reduce inbreeding risk. Here, we aim to determine the mechanism of kin recognition for incest avoidance in the Damaraland mole-rat , a cooperative breeder characterized by extreme reproductive skew. Pairs of opposite-sex adults were formed in the laboratory and, within pairs, genetic relatedness and degree of familiarity were manipulated through cross-fostering experiments. We found that unfamiliar pairs were more likely to engage in sexual behaviours and bred more successfully than familiar pairs, regardless of their genetic similarity. Females paired with unfamiliar males were also more likely to exhibit reproductive activation, characterized by increased levels of oestradiol and progesterone. This study shows that in Damaraland mole-rats, inbreeding avoidance can be achieved through a discrimination mechanism that relies on association during rearing, and that ovulation is induced by mating. This study advances our understanding of incest avoidance in species with constrained dispersal.
在不同的分类群中，近亲繁殖通常是避免的，因为它会给后代带来适应度成本。通过两性从出生地扩散到繁殖地来避免乱伦。在一些亲代物种中，亲属之间的联系会延伸到成年期，个体可能需要有辨别亲属的能力，以降低近亲繁殖的风险。在这里，我们旨在确定达马拉兰鼹鼠（一种以极端生殖偏斜为特征的合作繁殖者）避免乱伦的亲缘识别机制。在实验室中形成了一对异性成年个体，并通过交叉抚育实验操纵了个体之间的遗传关系和熟悉程度。我们发现，不熟悉的个体比熟悉的个体更有可能发生性行为，繁殖成功率也更高，而不管它们的遗传相似性如何。与不熟悉的雄性配对的雌性也更有可能表现出生殖激活，其特征是雌激素和孕激素水平升高。这项研究表明，在达马拉兰鼹鼠中，通过一种依赖于养育期关联的辨别机制，可以避免近亲繁殖，并且排卵是由交配诱导的。这项研究增进了我们对受限制扩散物种中避免乱伦的理解。
