Genetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, India.
J Evol Biol. 2010 Sep 1;23(9):1979-88. doi: 10.1111/j.1420-9101.2010.02061.x. Epub 2010 Jul 31.
Geographical variation in traits related to fitness is often the result of adaptive evolution. Stress resistance traits in Drosophila often show clinal variation, suggesting that selection affects resistance traits either directly or indirectly. Multiple stress resistance traits were investigated in 45 natural populations of Drosophila ananassae collected from all over India. There was significant positive correlation between starvation resistance and lipid content. Significant negative correlations between desiccation and lipid content and between desiccation and heat resistance were also found. Flies from lower latitudes had higher starvation resistance, heat resistance and lipid content but the pattern was reversed for desiccation resistance. These results suggest that flies from different localities varied in their susceptibility to starvation because of difference in their propensity to store body lipid. Multiple regression analysis provided evidence of climatic selection driven by latitudinal variation in the seasonal amplitude of temperature and humidity changes within the Indian. Finally, our results suggest a high degree of variation in stress resistance at the population level in D. ananassae.
与适应度相关的地理特征差异通常是适应进化的结果。果蝇的抗逆性特征通常表现出渐变变异，这表明选择要么直接、要么间接地影响了抗性特征。本研究调查了来自印度各地的 45 个自然果蝇种群中的多种抗逆性特征。饥饿抗性和脂质含量之间存在显著的正相关，而脱水和脂质含量之间以及脱水和耐热性之间存在显著的负相关。来自低纬度地区的果蝇具有更高的饥饿抗性、耐热性和脂质含量，但脱水抗性则相反。这些结果表明，由于储存体脂的倾向不同，来自不同地区的果蝇对饥饿的敏感性不同。多元回归分析提供了证据，证明气候选择是由印度内部温度和湿度季节性幅度的纬度变化驱动的。最后，我们的研究结果表明，在 D. ananassae 种群水平上存在高度的抗逆性变异。
