Department of Evolution, Ecology and Behaviour, Institute of Infection, Veterinary, and Ecological Sciences, University of Liverpool, Liverpool, UK.
Université de Lyon, VetAgro Sup, Marcy-l'Etoile, France.
J Evol Biol. 2021 Apr;34(4):661-670. doi: 10.1111/jeb.13768. Epub 2021 Mar 3.
In vertebrates, offspring survival often decreases with increasing maternal age. While many studies have reported a decline in fitness-related traits of offspring with increasing maternal age, the study of senescence in maternal effect through age-specific changes in offspring physiological condition is still at its infancy. We assessed the influence of maternal age and body mass on offspring physiological condition in two populations of roe deer (Capreolus capreolus) subjected to markedly different environmental conditions. We measured seven markers to index body condition and characterize the immune profile in 86 fawns which became recently independent of their known-aged mothers. We did not find striking effects of maternal age on offspring physiological condition measured at 8 months of age. This absence of evidence for senescence in maternal effects is likely due to the strong viability selection observed in the very first months of life in this species. Offspring physiological condition was, on the other hand, positively influenced by maternal body mass. Between-population differences in environmental conditions experienced by fawns also influenced their average body condition and immune phenotype. Fawns facing food limitation displayed lower values in some markers of body condition (body mass and haemoglobin levels) than those living in good quality habitat. They also allocated preferentially to humoral immunity, contrary to those living in good conditions, which allocated more to cellular response. These results shed a new light on the eco-physiological pathways mediating the relationship between mother's mass and offspring condition.
在脊椎动物中，后代的存活率通常随母体年龄的增加而降低。虽然许多研究报告称，随着母体年龄的增加，后代与适应度相关的特征会下降，但通过研究母体年龄对后代生理状况的影响来研究衰老问题仍处于起步阶段。我们评估了在两个不同环境条件下的马鹿（Capreolus capreolus）种群中，母体年龄和体重对后代生理状况的影响。我们测量了 7 个指标来评估 86 只刚离开已知年龄的母亲的幼鹿的身体状况，并描述了它们的免疫特征。我们没有发现母体年龄对 8 月龄幼鹿生理状况有明显影响。这种在母代效应中没有衰老证据的情况可能是由于在该物种生命的头几个月中观察到的强烈生存选择。另一方面，母体体重对后代的生理状况有积极影响。幼鹿在不同环境条件下的种群差异也影响了它们的平均身体状况和免疫表型。面临食物限制的幼鹿在一些身体状况指标（体重和血红蛋白水平）上的数值低于那些生活在良好栖息地的幼鹿。它们还优先分配给体液免疫，而不是那些生活在良好条件下的幼鹿，后者则更倾向于细胞反应。这些结果为介导母亲体重和后代状况之间关系的生态生理途径提供了新的认识。
