Metabolic reserves and evolved stress resistance in Drosophila melanogaster
Metabolic reserves and evolved stress resistance in Drosophila melanogaster
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DOI：
10.1086/515963
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发表时间：
1998-09-01
期刊：
影响因子：
--
通讯作者：
Bradley, TJ
中科院分区：
文献类型：
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作者：
Djawdan, M;Chippindale, AK;Bradley, TJ
我们已经研究了饥饿和干燥抗性在43个远交种群的果蝇已经偏离了一个共同的祖先人口作为一个结果，各种定义的选择协议。种群差异高达8.5倍的抗干燥性和高达10倍的抗饥饿性。我们利用这些种群来寻找进化的生理变化，这些变化可能解释应激抵抗力的差异。我们研究了先前文献中提出的两种增加胁迫抗性的假设：（1）饥饿抗性的增加主要是不同脂质积累的结果，（2）糖原积累的变化在对干燥胁迫抗性的进化增加中起作用。通过量化我们的每个果蝇种群中的抗干燥性、抗饥饿性、脂质含量和碳水化合物含量，我们能够证明果蝇抵抗饥饿的能力与果蝇储存的脂质或碳水化合物的量之间的强相关性，最强的相关性（R-2 = 0.99）时，观察到的总能量含量的脂肪和碳水化合物的商店对饥饿抗性回归。这些结果表明，果蝇通过遗传决定的脂质和碳水化合物储存的增加对饥饿抗性的选择作出反应。对脂质储存或总能量储存与抗干燥性之间的相关性进行类似的分析，结果显示无显著相关性。碳水化合物储存与雌性果蝇的抗干燥性显著相关，但与雄性果蝇无关。这些结果表明，不同形式的压力抵抗不同的生理机制和进化反应的苍蝇的压力选择是特定的压力施加。
We have examined starvation and desiccation resistance in 43 outbred populations of Drosophila melanogaster that have diverged from a common ancestral population as a result of a variety of defined selection protocols. The populations differ up to 8.5-fold in desiccation resistance and up to 10-fold in starvation resistance. We used these populations to search for evolved physiological changes that might explain the differences in stress resistance. We examined two hypotheses for increased stress resistance that had been proposed previously in the literature: (1) that increments in starvation resistance are principally the result of differential lipid accumulation, and (2) that changes in glycogen accumulation play a role in evolved increases in resistance to desiccation stress. By quantifying desiccation resistance, starvation resistance, lipid content, and carbohydrate content in each of our populations of flies, we were able to demonstrate strong correlations between the capacity of the flies to resist starvation and the quantity of lipid or carbohydrate that the flies had stored, The strongest correlation (R-2 = 0.99) was observed when the total energy content of both the lipid and carbohydrate stores was regressed against starvation resistance. These results demonstrate that the flies responded to selection for starvation resistance through a genetically determined increase in both lipid and carbohydrate storage. Similar analyses of the correlation between lipid storage or total energy storage and desiccation resistance revealed no significant correlations. Carbohydrate storage was significantly correlated with desiccation resistance in female but not in male flies. These results suggest that different forms of stress are resisted with distinct physiological mechanisms and that the evolutionary response of the flies to stress selection is specific to the stress imposed.