Evolution of a novel female reproductive strategy in Drosophila melanogaster populations subjected to long term protein restriction

Reproductive output is often constrained by availability of macronutrients, especially protein. Long term protein restriction, therefore, is expected to select for traits maximizing reproduction even under nutritional challenge. We subjected four replicate populations of Drosophila melanogaster to a complete deprivation of yeast supplement, thereby mimicking a protein restricted ecology. Following 24 generations, compared to their matched controls, females from experimental populations showed increased reproductive output early in life, both in presence and absence of yeast supplement. The observed increase in reproductive output was without associated alterations in egg size, development time, pre-adult survivorship, body mass at eclosion, and lifespan of the females. Further, selection was ineffective on lifelong cumulative fecundity. However, females from experiment regime were found to have a significantly faster rate of reproductive senescence following the attainment of the reprod...生殖产出常受大量营养素（macronutrients）可获得性的限制，尤以蛋白质为甚。因此，长期蛋白质限制应会筛选出即便在营养胁迫下也能最大化生殖产出的性状。我们将四组重复的黑腹果蝇（Drosophila melanogaster）种群置于完全剥夺酵母补充剂的环境中，以此模拟蛋白质限制的生态环境。经过24代培育后，与匹配对照组相比，实验组种群的雌性果蝇在生命早期的生殖产出显著提升，无论是否添加酵母补充剂。本次观测到的生殖产出提升，并未伴随雌性果蝇的卵大小、发育时长、成虫前期存活率（pre-adult survivorship）、羽化（eclosion）时体重及寿命出现相关变化。此外，针对终身累计繁殖力（lifelong cumulative fecundity）的选择并未产生显著效果。然而，实验组雌性果蝇在达到生殖阶段后的生殖衰老（reproductive senescence）速率显著更快……