Age-specific patterns of genetic variance in Drosophila melanogaster. I. Mortality.
Age-specific patterns of genetic variance in Drosophila melanogaster. I. Mortality.
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果蝇遗传变异的年龄特异性模式。
DOI：
10.1093/genetics/143.2.839
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发表时间：
1996
期刊：
影响因子：
3.3
通讯作者：
Curtsinger,JW
中科院分区：
文献类型：
--
作者：
Promislow,DE;Tatar,M;Khazaeli,AA;Curtsinger,JW
PeterMedawar提出，衰老是由于与年龄相关的选择力下降，这使得晚作用的有害突变积累起来。随后的工作者提出，突变积累可能会产生与年龄相关的适应性性状的加性遗传方差（VA）增加，最近在果蝇中发现。在这里，我们报告了65，134 D死亡率的遗传分析结果。黑腹菌雌性死亡率的加性遗传方差从出生后第一周的0.007增加到第三周的0.325，然后下降到第七周的0.002。男性表现出类似的模式，但总方差低于女性。与预测的死亡率曲线趋异相反，不同基因型的死亡率曲线大致平行。使用一个三参数模型，我们发现显着的V，曲线的斜率和常数项描述年龄特定的死亡率，也为死亡率在生命后期减速的速度。这些结果不支持来自MEDAWAR的“突变积累”理论的预测衰老的演变。然而，我们的研究结果可能与衰老进化模型的其他解释一致。
PeterMedawarproposed that senescence arises from an age-related decline in the force of selection, which allows late-acting deleterious mutations to accumulate. Subsequent workers have suggested that mutation accumulation could produce an age-related increase in additive genetic variance (VA) for fitness traits, as recently found inDrosophila melanogaster. Here we report results from a genetic analysis of mortality in 65,134D. melanogaster. Additive genetic variance for female mortality rates increases from 0.007 in the first week of life to 0.325 by the third week, and then declines to 0.002 by the seventh week. Males show a similar pattern, though total variance is lower than in females. In contrast to a predicted divergence in mortality curves, mortality curves of different genotypes are roughly parallel. Using a three-parameter model, we find significant V, for the slope and constant term of the curve describing age-specific mortality rates, and also for the rate at which mortality decelerates late in life. These results fail to support a prediction derived from MEDAWAR'S “mutation accumulation” theory for the evolution of senescence. However, our results could be consistent with alternative interpretations of evolutionary models of aging.