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

母性效应描述了母性和子代特征之间相互作用的非遗传成分。卵子是研究母体效应的理想系统，因为孵化前的投资可以直接衡量，并与后代的表现相关。在1997年对一群野生鸟类的研究中，个体孵化的蛋的大小解释了在孵化后的头两周内遗传相关个体死亡率的显著差异。孵化时剩余的卵黄量和卵黄睾酮是两种母体效应，这可能为大子代和小子代的存活率差异提供了机制上的理解。在项目一中，研究者将控制孵化时剩余的蛋黄数量，并探索这些蛋黄储备对孵化的小鸡生长、发育和存活的影响。在项目二中，研究者将描述鸡蛋中的卵黄睾酮，并使用培育方案将其与孵化后的小鸡表现联系起来。这种培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系影响的变化和对后代表现的后续影响的有力分析。

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.