The effects of stabilizing selection on the time of development in Drosophila melanogaster
The effects of stabilizing selection on the time of development in Drosophila melanogaster
复制标题
稳定选择对果蝇发育时间的影响
DOI：
10.1017/s0016672300003219
复制
发表时间：
1962
影响因子：
1.5
通讯作者：
T. Prout
中科院分区：
文献类型：
--
作者：
T. Prout
黑腹果蝇从产卵到羽化的发育时间长度受到稳定化选择的影响。在每一代中，只有接近平均发育时间出现的个体才被用作下一代的亲本。这条线被称为“S”线。在一个平行线破坏性的选择进行了实践;在每一代最早出现的苍蝇交配苍蝇最后出现;那些出现在中间时间被丢弃。这条线被称为“D”线。还进行了两个对照线，其中苍蝇相对于出现时间随机交配。结果表明：（1）与对照相比，S系发育时间的方差减小，D系发育时间的方差增大; (2)S系的平均发育时间缩短，D系的平均发育时间延长。(3)变异系数在S系中减小，在D系中增大。(4)生存能力，以苍蝇出现的百分比衡量，在D线下降。在实验结束时，根据对定向选择的反应估计所选品系和对照品系中的加性遗传方差的量。估计表明，（i）在S线的总方差的损失可以完全占加性遗传方差的损失，和（ii）在D线的总方差的增加不能归因于加性遗传方差的增加。这可能是由于方差的环境成分增加，即"缓冲能力"的丧失。
The length of time of development, from oviposition to emergence in Drosophila melanogaster was subjected to stabilizing selection. In each generation only the individuals emerging close to the mean development time were used as parents of the next generation. This line was designated the ‘S’ line. In a parallel line disruptive selection was practised; where in each generation the earliest flies to emerge were mated to the flies last to emerge; those emerging at intermediate times were discarded. This line was designated the ‘D’ line. Two control lines were also carried, where the flies were mated at random with respect to time of emergence. The experiment extended for 40 generations and produced the following results: (1) The variance of development time decreased in the S line and increased in the D line, relative to the control lines. (2) The mean development time decreased in the S line and increased in the D line. (3) The coefficients of variation decreased in the S line and increased in the D line. (4) The viability, measured as per cent flies emerging, decreased in the D line. Toward the end of the experiment the amount of additive genetic variance in the selected lines and in the control lines was estimated from the response to directional selection. The estimates showed that (i) the loss of total variance in the S line can be accounted for completely by a loss in additive genetic variance, and (ii) the increase in the total variance of the D line cannot be ascribed to an increase in the additive genetic variance. It was probably due to an increase in the environmental component of variance, i.e. to a loss of ‘buffering capacity’.