Population and Biochemical Aspects of D. melanogaster G6PD.

本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重要的代谢途径。作为一个模型系统，研究重点是果蝇葡萄糖-6-磷酸脱氢酶（G6PD）。先前的研究已经表明了生物化学特性的显著差异，但尚不清楚这些在试管中确定的差异是否反映了遗传变异在活蝇（体内）中的功能。这个问题将通过检查放射性标记葡萄糖的量通过代谢途径在苍蝇具有任何遗传变异的酶来解决。这个测试对于我们理解自然发生的酶变异是至关重要的，因为通常认为人工的体外生化功能测量与其体内功能之间存在一对一的对应关系。然而，还没有直接的实验来验证这一假设。这是对这一假设的关键实验检验，在少数几个可以直接检验的系统之一。

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.