Using experimental evolution to study the physiological mechanisms of desiccation resistance in Drosophila melanogaster
Using experimental evolution to study the physiological mechanisms of desiccation resistance in Drosophila melanogaster
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DOI：
10.1086/518354
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发表时间：
2007-07-01
影响因子：
1.6
通讯作者：
Rose, Michael R.
中科院分区：
文献类型：
--
作者：
Archer, Margaret A.;Bradley, Timothy J.;Rose, Michael R.
从正在经历实验进化的种群中获得的数据可用于在生理分化的种群之间进行比较，并确定进化轨迹。对长期建立的黑腹果蝇实验室种群进行比较，这些种群在干燥抗性方面有很强的分化，用于测试有关果蝇在极端干燥环境中生存机制的替代假设。这项比较研究支持了这样一个假设，即至少在一种情况下，D. melanogaster可以通过降低失水率和增加体积含水量而不是通过增加代谢含水量或脱水耐受性来进化出对干燥的抵抗力。虽然糖原参与了水的储存，但它的主要作用是水的结合，而不是代谢水的产生。在选择抗旱性过程中，对这些成分机制的轨迹测量表明，水分流失率在选择过程中迅速趋于平稳，而含水量则继续提高。这种差异揭示了研究进化轨迹的价值以及进化生理学中长期选择研究的必要性。
Data from populations undergoing experimental evolution can be used to make comparisons between physiologically differentiated populations and to determine evolutionary trajectories. Comparisons of long-established laboratory populations of Drosophila melanogaster that are strongly differentiated with respect to desiccation resistance are used to test alternative hypotheses concerning the mechanisms that fruit flies use to survive bouts of extreme desiccation. This comparative study supports the hypothesis that, in at least one case, D. melanogaster can evolve increased resistance to desiccation by decreasing water loss rates and by increasing bulk water content but not by increasing metabolic water content or dehydration tolerance. While glycogen was involved in water storage, its primary role was in water binding, not the production of metabolic water. Measurement of the trajectories of these component mechanisms during selection for desiccation resistance is used to demonstrate that water loss rate quickly plateaus in response to selection, while water content continues to improve. This disparity reveals the value of studying evolutionary trajectories and the need for longer-term selection studies in evolutionary physiology.