Bloch Qazi Margaret C, Miller Paige B, Poeschel Penny M, Phan Mai H, Thayer Joseph L, Medrano Christian L
Department of Biology, Gustavus Adolphus College, 800 West College Avenue, Saint Peter, MN 56082, USA.
J Insect Physiol. 2017 Jul;100:43-52. doi: 10.1016/j.jinsphys.2017.05.007. Epub 2017 May 19.
In non-social insects, fitness is determined by relative lifetime fertility. Fertility generally declines with age as a part of senescence. For females, senescence has profound effects on fitness by decreasing viability and fertility as well as those of her offspring. However, important aspects of these maternal effects, including the cause(s) of reduced offspring performance and carry-over effects of maternal age, are poorly understood. Drosophila melanogaster is a useful system for examining potential transgenerational effects of increasing maternal age, because of their use as a model system for studying the physiology and genetic architecture of both reproduction and senescence. To test the hypothesis that female senescence has transgenerational effects on offspring viability and development, we measured the effects of maternal age on offspring survival over two generations and under two larval densities in two laboratory strains of flies (Oregon-R and Canton-S). Transgenerational effects of maternal age influence embryonic viability and embryonic to adult viability in both strains. However, the generation causing the effects, and the magnitude and direction of those effects differed by genotype. The effects of maternal age on embryonic to adult viability when larvae are stressed was also genotype-specific. Maternal effects involve provisioning: older females produced smaller eggs and larger offspring. These results show that maternal age has profound, complex, and multigenerational consequences on several components of offspring fitness and traits. This study contributes to a body of work demonstrating that female age is an important condition affecting phenotypic variation and viability across multiple generations.
在非社会性昆虫中，适合度由相对终生繁殖力决定。作为衰老的一部分，繁殖力通常会随着年龄增长而下降。对于雌性而言，衰老通过降低自身以及后代的生存能力和繁殖力，对适合度产生深远影响。然而，这些母体效应的重要方面，包括后代表现下降的原因以及母体年龄的延续效应，目前还知之甚少。黑腹果蝇是研究母体年龄增加可能产生的跨代效应的有用系统，因为它被用作研究繁殖和衰老的生理学及遗传结构的模型系统。为了验证雌性衰老对后代生存能力和发育具有跨代效应这一假设，我们在两种实验室果蝇品系（俄勒冈 - R和广东 - S）中，测量了母体年龄对两代后代在两种幼虫密度下生存情况的影响。母体年龄的跨代效应影响了两个品系中胚胎的生存能力以及从胚胎到成虫的生存能力。然而，产生这些效应的代际、效应的大小和方向因基因型而异。当幼虫受到压力时，母体年龄对从胚胎到成虫生存能力的影响也是基因型特异性的。母体效应涉及营养供应：年龄较大的雌性产生的卵较小，后代较大。这些结果表明，母体年龄对后代适合度和性状的多个组成部分具有深远、复杂且多代的影响。这项研究为一系列表明雌性年龄是影响多代表型变异和生存能力的重要条件的研究工作做出了贡献。
