MOLECULAR POPULATION GENETICS OF ADH IN DROSPHILA

拟议研究的目标是分析种内 的核苷酸序列和种间变异 表型单态基因座决定重要 产生和维持核苷酸多样性的进化力量 在自然种群中。核苷酸多样性是终极 允许有机体适应的表型变异的来源 自然人口面临的新环境挑战，如 获得抗病能力。因此，重要的是要了解 调节基因水平的进化力量 自然种群的变异。此外，进化的 表型简单的遗传基因座的动力学必须是 在形成图案的进化力量之前被理解 和表型复合体的核苷酸多样性的组织 基因定位是可以确定的。 拟议的研究将对100个物种的核苷酸多样性进行采样 乙醇脱氢酶(ADH)区的核苷酸序列 来自五个自然群体的表型单态基因座 拟黑腹果蝇和拟黑果蝇种群 检验这一轨迹是否符合中性理论的预测 分子进化论。一个表型单一的基因座应该 按照中立理论的预测行事 缺乏其他进化力量，如自然选择。 任何与中立者预测的背离 假黑斑潜蝇Adh区的模型将表明 自然选择的行为可能会塑造图案和 核苷酸多样性在表型上的组织 单态轨迹。

The objective of the proposed study is to analyze the intraspecific and interspecific variation of nucleotide sequences of a phenotypically monomorphic locus to determine the important evolutionary forces that generate and maintain nucleotide diversity in natural populations. Nucleotide diversity is the ultimate source of phenotypic variation which allows organisms to adapt to new environmental challenges in natural populations such as acquiring disease resistance. Thus, it is important to understand the evolutionary forces that modulate the levels of genetic variation in natural populations. In addition, the evolutionary dynamics of a genetic locus that is phenotypically simple must be understood before the evolutionary forces that shape the pattern and organization of nucleotide diversity of phenotypically complex loci can be ascertained. The proposed study will sample the nucleotide diversity of 100 nucleotide sequences of the alcohol dehydrogenase (Adh) region, a phenotypically monomorphic locus, from five natural populations of Drosophila pseudoobscura and one population of D. persimilis to test whether this locus fits the predictions of the neutral theory of molecular evolution. A phenotypically monomorphic locus should behave according to the predictions of the neutral theory in the absence of other evolutionary forces such as natural selection. Any departures from the predictions of the neutral model seen in the Adh region of D. pseudoobscura will suggest that the action of natural selection may shape the pattern and organization of nucleotide diversity at a phenotypically monomorphic locus.