Dissertation Research: An Analysis of Maternal Effects in the American Coot: Consequences for Offspring Growth and Survival

弗莱克9801503母性效应描述了母子之间相互作用的非遗传成分特征。鸡蛋是研究母体影响的理想系统，因为孵化前的投资可以直接测量，并与随后的后代表现相关。在1997年研究的一组野生鸟类中，孵化出的个体的蛋大小解释了在孵化后的头两周内，遗传相关个体之间死亡率的显著差异。孵化时剩余的卵黄量和蛋黄睾丸素是两种母性效应，它们可能提供了对大小后代存活差异的机械性理解。在第一个项目中，研究人员将操纵孵化时剩余的卵黄量，并探索这些蛋黄储备对幼崽生长、发育和存活的影响。在第二个项目中，研究人员将研究蛋黄中的睾丸激素，并使用培育方案将其与雏鸟孵化后的表现相关联。这种养育设计允许区分孵化前和孵化后的母体效应。这两个项目都提供了对母体效应的变化以及随后对后代表现的影响的强有力的分析。

Vleck 9801503 Maternal effects describe the non-genetic component of the interaction between mother and offspring characteristics. Eggs are an ideal system in which to study maternal effects because investments made prior to hatching can be measured directly and correlated with subsequent offspring performance. In a population of wild birds studied in 1997, the egg size from which an individual hatched explained a significant amount of the variation in mortality among genetically related individuals during the first two weeks after hatch. The amount of yolk remaining at hatch and yolk testosterone are two maternal effects which may provide a mechanistic understanding of the differences in survival between large and small offspring. In project one the investigator will manipulate the amount of yolk remaining at hatch and explore the effects of these yolk reserves on hatchling growth, development and survival. In project two the investigator will characterize yolk testosterone in eggs and correlate this with chick performance after hatch using a fostering protocol. This fostering design allows for the distinction between pre-hatching and post-hatching maternal effects. Both projects provides for a powerful analysis of variation in maternal effects and the subsequent consequences to offspring performance.