目的:妊娠失败是任何哺乳动物的主要健身成本,特别是那些生活史缓慢的人,如灵长类动物。这里,我们量化了野生杂种狒狒胎儿丢失的风险,包括遗传,生态,和差异的人口统计来源。我们对检验杂交增加胎儿损失率的假设特别感兴趣。这种效应将有助于解释狒狒如何保持遗传和表型完整性,尽管种间基因流动。
方法:我们分析了在自然的黄色狒狒-anubis狒狒杂种区,在46年中观察到的1020次怀孕的结果。根据女性生殖状态的记录和活产新生儿的出现对胎儿损失和活产进行评分。我们将胎儿丢失的概率建模为女性遗传祖先的函数(估计她的基因组比例来自阿努比[与黄色]祖先),年龄,先前胎儿损失的数量,优势等级,组大小,气候,和生境质量使用二项混合效应模型。
结果:女性遗传祖先不能预测胎儿丢失。相反,非常年轻和非常年老的女性胎儿丢失的风险增加。胎儿损失是生态因素最有力的预测,包括家庭范围转移之前的栖息地质量差和怀孕期间的极端高温。
结论:我们的研究结果表明,杂交母鼠的胎儿丢失风险增加不会阻碍黄狒狒和无乳狒狒之间的基因流动。相反,生态条件和女性年龄是女性生殖成功的关键因素。
Pregnancy failure represents a major fitness cost for any mammal, particularly those with slow life histories such as primates. Here, we quantified the risk of fetal loss in wild hybrid baboons, including genetic, ecological, and demographic sources of variance. We were particularly interested in testing the hypothesis that hybridization increases fetal loss rates. Such an effect would help explain how baboons may maintain genetic and phenotypic integrity despite interspecific gene flow.
We analyzed outcomes for 1020 pregnancies observed over 46 years in a natural yellow baboon-anubis baboon hybrid zone. Fetal losses and live births were scored based on records of female reproductive state and the appearance of live neonates. We modeled the probability of fetal loss as a function of a female\'s genetic ancestry (the proportion of her genome estimated to be descended from anubis [vs. yellow] ancestors), age, number of previous fetal losses, dominance rank, group size, climate, and habitat quality using binomial mixed effects models.
Female genetic ancestry did not predict fetal loss. Instead, the risk of fetal loss is elevated for very young and very old females. Fetal loss is most robustly predicted by ecological factors, including poor habitat quality prior to a home range shift and extreme heat during pregnancy.
Our results suggest that gene flow between yellow and anubis baboons is not impeded by an increased risk of fetal loss for hybrid females. Instead, ecological conditions and female age are key determinants of this component of female reproductive success.