Inferring the demographic history of Drosophila subobscura from nucleotide variation at regions not affected by chromosomal inversions

Drosophila subobscura presents a rich and complex chromosomal inversion polymorphism. It can thus be considered a model system i) to study the mechanisms originating inversions and how inversions affect the levels and patterns of variation in the inverted regions, and ii) to study adaptation at both the single-gene and chromosomal inversion levels. It is therefore important to infer its demographic history since previous information indicated that its nucleotide variation is not at mutation-drift equilibrium. For that purpose, we sequenced 16 non-coding regions distributed across those parts of the J chromosome not affected by inversions in the studied population and possibly either by other selective events. The pattern of variation detected in these 16 regions is similar to that previously reported within different chromosomal arrangements, suggesting that the latter results would, thus, mainly reflect recent demographic events rather than the partial selective sweep imposed by the or...

暗果蝇（Drosophila subobscura）具有丰富且复杂的染色体倒位多态性（chromosomal inversion polymorphism）。因此，它可被视为理想的模型系统（model system），用于：i) 研究倒位产生的机制，以及倒位如何影响倒位区域内变异的水平与模式；ii) 从单基因和染色体倒位两个层面探究适应性。鉴于此前研究表明其核苷酸变异（nucleotide variation）未处于突变-漂移平衡（mutation-drift equilibrium）状态，推断其种群历史（demographic history）具有重要意义。为此，我们对研究种群中J染色体未受倒位影响、且可能未受其他选择事件（selective events）干扰的区域内分布的16个非编码区域（non-coding regions）进行了测序。在这16个区域中检测到的变异模式与此前不同染色体排列（chromosomal arrangements）中报道的模式相似，这表明后者的结果主要反映了近期的种群事件，而非由...带来的部分选择性清除（selective sweep）。