Dissertation Research: A Functional and Mechanistic Investigation of Yolk Androgens in the European Starling (Sturnus Vulgaris)

论文研究：欧洲八哥 (Sturnus Vulgaris) 卵黄雄激素的功能和机制研究

• 批准号: 0104907
• 负责人: Elizabeth Adkins-Regan
• 金额: --
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-05-15 至 2003-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0104907&HistoricalAwards=false
• 关键词: Dissertation; Research; Functional; Mechanistic; Investigation

Dissertation Research: A Functional and Mechanistic Investigation of Yolk Androgens in the European Starling (Sturnus Vulgaris)Elizabeth Adkins-Regan and Kevin PilzFemale birds deposit steroid hormones, such as testosterone, in the yolks of their eggs. In captive-bred canaries, high levels of "yolk testosterone" in eggs cause elevated growth rates and begging behavior in the chicks that hatch from those eggs. There is currently no information regarding the behavioral effects of yolk hormones in other species of birds. Nor is there well-substantiated evidence that females deposit different levels of hormones in eggs under different ecological circumstances to maximize their reproductive success. This study intends to fills these gaps in our knowledge by studying two types of "yolk androgens", one being testosterone and the other being a related hormone called androstenedione, in wild-living European starlings (Sturnus vulgaris). The first goal of this research is to document the effects of yolk androgens on European starling chick growth and behavior. Eggs will be injected with hormone or with a control solution and the growth and begging behavior of the chicks will be monitored until the chicks are ready to leave the nest. The second goal of this research is to test the hypothesis that females who engage in the reproductive strategy of brood parasitism deposit high levels of yolk androgens in their eggs. A brood parasite female lays her eggs in the nests of other females to avoid raising the chicks herself; starlings sometimes brood parasitize other starlings. If yolk androgens cause chicks to compete more, by begging more and growing faster, then a female who lays brood parasitic eggs should deposit high levels of androgen in those eggs so that her chicks will be able to selfishly outcompete their unrelated nestmates. The third goal of this research is to examine whether female characteristics such as body size and age are related to the levels of yolk androgens that females deposit in eggs. This data will be used to determine if the small size and young age of brood parasitic females may explain why brood parasitic eggs have high levels of yolk androgens. This data will also be used to test the hypothesis that "high quality" females (larger, older females) should invest more yolk androgens in eggs than "low quality" females. In summary, this research will investigate within a single species of wild songbird, 1) the effects of yolk androgens on chicks; 2) whether females allocate androgens to eggs in ways which benefit their reproductive success; and 3) whether female allocation of yolk androgens varies with female characteristics such as body size and age. This research will increase our knowledge of hormone effects on development in birds and provide understanding of non-genetic means by which females can adaptively manipulate offspring characteristics. The research may also be useful as a model of maternal hormone effects on developing offspring in mammalian species.

论文研究：对欧洲八哥雄激素（Sturnus vulgaris）伊丽莎白·阿德金斯·雷根（Elizabeth Adkins-Regan）和凯文·皮尔兹菲马莱（Kevin Pilzfemale）鸟类对卵卵巢中的类固醇激素（如睾丸激素）沉积的蛋黄雄激素的功能和机械研究。在圈养的金丝雀中，卵中的高水平的“蛋黄睾丸激素”导致了从这些卵子孵化的小鸡的生长速度和乞讨行为。目前尚无有关蛋黄激素在其他鸟类中的行为影响的信息。也没有良好的证据表明，在不同的生态环境下，女性在卵中沉积了不同水平的激素，以最大程度地发挥其生殖成功。这项研究打算通过研究两种类型的“蛋黄雄激素”来填补这些差距，其中一种是睾丸激素，另一种是一种称为雄激素的激素，称为雄心勃勃的欧洲八哥（Sturnus fulgaris）。这项研究的第一个目标是记录蛋黄雄激素对欧洲八哥鸡的生长和行为的影响。鸡蛋将注入激素或对照溶液，并将监测小鸡的生长和乞讨行为，直到小鸡准备离开巢。这项研究的第二个目标是检验以下假设：从事育雏寄生虫生殖策略的女性将高水平的蛋黄雄激素沉积在卵中。一个育雏的寄生虫雌性将鸡蛋放在其他雌性的巢中，以避免自己抚养小鸡。八哥有时育雏会寄生其他街头。如果蛋黄雄激素会导致小鸡竞争更多，乞求更多和更快的速度，那么在那些卵中产下育雏寄生卵的女性应将高水平的雄激素沉积在这些卵中，以便她的小鸡能够自私地胜过他们无关的巢穴。这项研究的第三个目标是检查女性特征（例如身体大小和年龄）是否与女性沉积在卵中的蛋黄雄激素的水平有关。这些数据将用于确定育雏寄生雌性的小尺寸和年轻年龄是否可以解释为什么育雏寄生卵具有高水平的蛋黄雄激素。这些数据还将用于检验以下假设：“高质量”女性（较大的年龄较大的女性）应该在卵上投入更多的蛋黄雄激素，而不是“低品质”的女性。总而言之，这项研究将在一种野生鸣禽中调查，1）蛋黄雄激素对雏鸡的影响； 2）女性是否会以有益于其生殖成功的方式将雄激素分配给卵； 3）女性分配蛋黄雄激素是否随女性特征（例如身体大小和年龄）而变化。这项研究将增加我们对激素对鸟类发育影响的了解，并提供对女性可以适应性操纵后代特征的非遗传手段的理解。这项研究也可能是孕产妇激素对哺乳动物物种发展后代的影响的模型。