Williams A E, Rose M R, Bradley T J
Department of Ecology and Evolutionary Biology, University of California, Irvine 92697, USA.
J Exp Biol. 1997 Feb;200(Pt 3):615-24. doi: 10.1242/jeb.200.3.615.
We used laboratory natural selection on insects as a means of investigating the role of patterns of gas exchange in desiccation resistance. We used 15 populations of Drosophila melanogaster: five selected for desiccation resistance, five control populations and five ancestral populations. Using flow-through respirometry, we found that D. melanogaster from all populations produced irregular peaks of CO2 release. To quantify the height and frequency of these peaks, we used the standard error of a linear regression (SER) through the recordings of CO2 release. The values for the SER were significantly larger in the populations selected for desiccation resistance than in the control and ancestral populations. Occasionally, highly periodic peaks of CO2 release were observed in the desiccation-resistant populations only. Maximum SER was found to be strongly correlated with survival time in dry air among selection treatments, but not among individuals within a population. Access to dietary water resulted in lower SER values. These data demonstrate that gas exchange is physiologically controlled in Drosophila melanogaster and that the pattern of gas exchange can change under selection. The relationship between these CO2 release patterns and classic discontinuous ventilation is discussed.
我们利用对昆虫进行实验室自然选择的方法，来研究气体交换模式在抗干燥能力中的作用。我们使用了15个黑腹果蝇种群：5个种群被选择用于抗干燥能力研究，5个作为对照种群，5个作为原始种群。通过流通式呼吸测定法，我们发现来自所有种群的黑腹果蝇都会产生不规则的二氧化碳释放峰值。为了量化这些峰值的高度和频率，我们通过二氧化碳释放记录使用线性回归的标准误差（SER）。在被选择用于抗干燥能力研究的种群中，SER值显著大于对照种群和原始种群。仅在抗干燥种群中偶尔观察到高度周期性的二氧化碳释放峰值。在选择处理中，发现最大SER与在干燥空气中的存活时间密切相关，但在一个种群内的个体之间并非如此。获取饮食中的水分会导致SER值降低。这些数据表明，黑腹果蝇的气体交换受到生理控制，并且气体交换模式在选择作用下会发生变化。本文还讨论了这些二氧化碳释放模式与经典的间断性通气之间的关系。
