DISSERTATION RESEARCH: A Hormonal Mechanism for the Maternal Transduction of Ecological Conditions to the Avian Embryo

当一只雌性以一种不完全归因于后代基因的方式改变她的后代时，母体效应就会发生。这些影响往往受到母亲生态环境的影响，但生态条件是如何通过母亲传递给后代的，人们对此知之甚少。这项建议涉及对荷尔蒙机制的调查，母鸟通过这些机制根据母体环境中的食物供应来改变鸟类胚胎的荷尔蒙环境。美国红隼的初步研究结果表明，食物的可获得性影响产卵雌性的血浆催乳素激素水平，血浆催乳素影响蛋黄中沉积的雄激素水平，蛋黄雄激素影响后代的存活。然而，目前尚不清楚食物是否会影响卵黄雄激素水平。在这项提议中，食物的可获得性将被操纵以确定它如何影响卵黄雄激素水平。母性效应在自然界中普遍存在，在许多植物物种、昆虫和所有种类的脊椎动物中都存在。这项研究可能揭示一种机制，通过这种机制，诸如食物可获得性之类的生态条件可能被转导到鸟类胚胎。很少有生物体描述了从环境到母体再到后代的机械性联系。

Maternal effects occur when a female modifies her offspring in a manner not attributable solely to the offspring's genes. Often these effects are influenced by the ecological environment of the mother, but how ecological conditions are transmitted through the mother to her offspring are poorly understood. This proposal involves the investigation of the hormonal mechanisms by which mother birds modify the avian embryo's hormonal milieu according to food availability in the maternal environment. Preliminary findings in the American kestrel indicate that food availability influences the laying female's blood-plasma levels of the hormone prolactin, that her plasma prolactin influences how much androgen hormone she deposits in her egg yolks, and that yolk androgens affect offspring survival. However, it is not known if food affects yolk androgen levels. In this proposal, food availability will be manipulated to determine how it affects yolk androgen levels.Maternal effects are ubiquitous in nature, occurring in numerous plant species, insects, and all classes of vertebrates. This study may reveal a mechanism by which ecological conditions such as food availability may be transduced to the avian embryo. A mechanistic link from the environment, through the mother, and to the offspring has been described in few if any organisms.