Population and Biochemical Aspects of D. melanogaster G6PD.

这项研究将研究在自然种群中发现的两种突变酶变体如何影响一条重要的代谢途径。本研究以果蝇体内葡萄糖-6-磷酸脱氢酶(G6PD)为模型系统进行研究。以前的研究已经表明了生化特性的显著差异，但尚不清楚在体外试管中确定的这些差异是否反映了遗传变异在活体苍蝇中的功能。这个问题将通过检查具有该酶基因变体的果蝇体内通过代谢途径的放射性标记葡萄糖的量来解决。这项测试对我们理解自然发生的酶变化是必不可少的，因为通常认为人工体外生化功能测量与它们在体内的功能之间存在一一对应关系。然而，从来没有进行过直接的实验来检验这一假设。这是对这一假设的关键实验检验，在为数不多的几个可以直接测试它的系统之一。

This research will examine how two mutant enzyme variants, found in natural populations, influence an important metabolic pathway. As a model system the study focuses on the enzyme glucose-6-phosphate dehydrogenase (G6PD) in the fruit fly, Drosophila melanogaster. Prior studies have indicated significant differences in biochemical properties, but it is unclear that these differences as determined in the test tube in vitro reflect how the genetic variants function in the living fly (in vivo). This question will be addressed by examining the amount of radioactively labelled glucose passed through the metabolic pathway in flies possessing either genetic variant of the enzyme. This test is essential to our understanding of naturally occurring enzyme variation because it is usually assumed that there is a one-to-one correspondence between artificial in vitro measures of biochemical function and their function in vivo. However, no direct experiments have ever been conducted to test this assumption. This is the crucial experimental examination of that assumption in one of the very few systems where it may be directly tested.