Harshman Lawrence G, Schmid Jeana L
School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588.
Evolution. 1998 Dec;52(6):1679-1685. doi: 10.1111/j.1558-5646.1998.tb02247.x.
An artificial selection experiment for increased female starvation resistance employed five selected lines and five control lines of Drosophila melanogaster. Females responded to selection within the first five generations, but a substantial male response was not observed until starvation resistance was assessed at generation 15. By measuring respiration rate in selected and control lines, it was possible to test the hypothesis that reduced metabolic rate is a general mechanism for stress resistance. There was no association between starvation resistance and respiration rate and thus no support for the hypothesis. Studies using vertebrates have shown that starvation causes a decrease in intermediary metabolism enzyme activity, but this relationship is not well documented in invertebrates. In the present study, intermediary metabolism enzyme activities decreased in response to starvation in control-line females and males, and in selected-line males. However, the selected females showed no overall decrease in enzyme activities in response to starvation. One interpretation is that selected females evolved to resist the phenotypic impact of stress. The concept of "counter-impact selection" is discussed in relationship to the use of phenotypic manipulations for the study of evolution.
一项针对提高雌性果蝇饥饿抗性的人工选择实验使用了五条选择品系和五条对照品系的黑腹果蝇。雌性果蝇在前五代中对选择有反应，但直到第15代评估饥饿抗性时才观察到雄性果蝇有显著反应。通过测量选择品系和对照品系的呼吸速率，有可能检验代谢率降低是抗应激的一般机制这一假设。饥饿抗性与呼吸速率之间没有关联，因此该假设未得到支持。使用脊椎动物的研究表明，饥饿会导致中间代谢酶活性降低，但这种关系在无脊椎动物中没有得到充分记录。在本研究中，对照品系的雌性和雄性以及选择品系的雄性果蝇，其中间代谢酶活性因饥饿而降低。然而，选择品系的雌性果蝇在饥饿状态下酶活性并未整体下降。一种解释是，选择品系的雌性果蝇进化出了抵抗应激表型影响的能力。本文结合表型操纵在进化研究中的应用，讨论了“反作用选择”的概念。
