Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain.
Mol Biol Evol. 2010 Jan;27(1):153-60. doi: 10.1093/molbev/msp220.
A usual approach to detect the spatial footprint left by recent adaptive events has been to follow up putative candidates emerging from multilocus scans of variation by sequencing additional fragments. We have used a similar experimental and analytical approach to study variation at 15 independently evolving and randomly chosen regions of the X chromosome of Drosophila melanogaster. These incompletely sequenced regions, each extending over approximately 40 kb, were subjected to two tests of positive selection that take into account the spatial distribution of nucleotide variation. Our analysis of variation at these genomic regions in a European population of D. melanogaster has allowed us to uncover a candidate region for positive selection and to empirically evaluate the comparative performance of the two tests of selection under a bottleneck scenario. Moreover, the boundaries here estimated for both the rate of adaptive substitution (delta) and the average selection coefficient (s) would support previous estimates obtained by maximum likelihood that suggest rather strong but uncommon positive selection.
一种常见的方法是通过对多基因座变异进行测序来追踪潜在的候选者，从而检测最近适应事件留下的空间足迹。我们使用了类似的实验和分析方法来研究黑腹果蝇 X 染色体上 15 个独立进化和随机选择的区域的变异。这些未完全测序的区域，每个区域约 40kb，都进行了两次正选择测试，考虑了核苷酸变异的空间分布。我们对欧洲黑腹果蝇种群中这些基因组区域的变异进行了分析，发现了一个正选择的候选区域，并在瓶颈情景下对两种选择测试的比较性能进行了实证评估。此外，这里估计的适应性替代率 (δ) 和平均选择系数 (s) 的边界将支持之前通过最大似然法得到的估计，表明存在相当强烈但不常见的正选择。
