Rako Lea, Blacket Mark J, McKechnie Stephen W, Hoffmann Ary A
Centre for Environmental Stress and Adaptation Research, Department of Genetics, University of Melbourne, Parkville, Victoria 3010, Australia.
Mol Ecol. 2007 Jul;16(14):2948-57. doi: 10.1111/j.1365-294X.2007.03332.x.
Clinal variation in traits often reflects climatic adaptation; in Drosophila melanogaster clinal variation provides an opportunity to link variation in chromosomal inversions, microsatellite loci and various candidate genes to adaptive variation in traits. We undertook association studies with crosses from a single population of D. melanogaster from eastern Australia to investigate the association between genetic markers and traits showing clinal variation. By genotyping parents and phenotyping offspring, we minimized genotyping costs but had the power to detect association between markers and quantitative traits. Consistent with prior studies, we found strong associations between the clinal chromosomal inversion In(3R)Payne and markers within it, as well as among these markers. We also found an association between In(3L)Payne and one marker located within this inversion. Of the five predicted associations between markers and traits, four were detected (increased heat, decreased cold resistance and body size with the heat shock gene hsr-omega S, increased cold resistance with the inversion In(3L)Payne), while one was not detected (heat resistance and the heat shock gene hsp68). In a set of eight exploratory tests, we detected one positive association (between hsp23a and heat resistance) but no associations of heat resistance with alleles at the hsp26, hsp83, Desat 2, alpha-Gpdh, hsp70 loci, while cold resistance was not associated with Frost and Dca loci. These results confirm interactions between hsr-omega and thermal resistance, as well as between In(3L)Payne and cold resistance, but do not provide evidence for associations between thermal responses and alleles at other clinically varying marker genes.
性状的渐变往往反映了气候适应性；在黑腹果蝇中，渐变提供了一个机会，可将染色体倒位、微卫星位点和各种候选基因的变异与性状的适应性变异联系起来。我们对来自澳大利亚东部的单一黑腹果蝇种群进行杂交，开展关联研究，以调查遗传标记与呈现渐变的性状之间的关联。通过对亲本进行基因分型并对后代进行表型分析，我们将基因分型成本降至最低，但仍有能力检测标记与数量性状之间的关联。与先前的研究一致，我们发现渐变染色体倒位In(3R)Payne与其内部的标记之间以及这些标记之间存在强关联。我们还发现In(3L)Payne与位于该倒位内的一个标记之间存在关联。在标记与性状之间的五个预测关联中，检测到了四个（热休克基因hsr-omega S与耐热性增加、耐寒性降低和体型减小有关，倒位In(3L)Payne与耐寒性增加有关），而有一个未检测到（耐热性与热休克基因hsp68）。在一组八项探索性测试中，我们检测到一个正相关（hsp23a与耐热性之间），但耐热性与hsp26、hsp83、Desat 2、alpha-Gpdh、hsp70位点的等位基因之间没有关联，而耐寒性与Frost和Dca位点没有关联。这些结果证实了hsr-omega与耐热性之间以及In(3L)Payne与耐寒性之间的相互作用，但没有提供热反应与其他临床可变标记基因的等位基因之间存在关联的确凿证据。
