Physiological Control of Gene Expression in a Seasonal Polyphenism

有些动物有两种不同的形态，这种现象被称为多表型。通常在一年中的不同季节会形成不同的形态。为了形成不同的形态，有必要激活一组不同的基因，因此控制多表型的问题是发现动物在两组可选择的基因中“选择”的机制。提出的研究目的是发展，第一次，在这种季节性多表型遗传控制的完整途径的理解。在这项研究中，我们将使用蝴蝶，Precis coenia，它具有戏剧性的颜色多酚性，我们的初步研究已经阐明了部分控制途径。拟议的研究将确定负责不同颜色形式的色素和负责它们合成的酶。这些酶的基因随后将被克隆，这样我们就可以开发工具来研究控制它们表达的机制。我们知道一种类固醇激素，20- oh -蜕皮激素，最终负责刺激导致替代色素合成发生的基因开关，并且将进行实验来开始研究它如何控制替代色素酶的差异表达。

Some species of animals occur in two different morphologies, a phenomenon called polyphenism. Usually the different alternative morphologies develop in different seasons of the year. In order to develop a different morphology it is necessary to activate a different set of genes, and thus the problem of control of polyphenism is to discover the mechanism by which an animal "chooses" between two alternative gene sets. The aim of the proposed research is to develop, for the first time, an understanding of complete pathway of genetic control in such a seasonal polyphenism. For this research we will use the butterfly, Precis coenia, which has a dramatic color polyphenism and for which our preliminary studies have already elucidated portions of the control pathway. The proposed research will identify the pigments responsible for the different color forms and the enzymes responsible for their synthesis. The genes for these enzymes will then be cloned so that we may develop tools to study the mechanism by which their expression is controlled. We know that a steroid hormone, 20-OH-ecdysone, is ultimately responsible for stimulating the genetic switch that causes the alternative pigment synthesis to occur, and experiments will be done to begin to investigate how this could control the differential expression of enzymes for the alternative pigments.