Ortiz-Barrientos Daniel, Chang Audrey S, Noor Mohamed A F
Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
Genet Res. 2006 Feb;87(1):23-31. doi: 10.1017/S0016672306007932.
Drosophila pseudoobscura has been intensively studied by evolutionary biologists for over 70 years. The recent publication of the genome sequence not only permits studies of comparative genomics with other dipterans but also opens the door to identifying genes associated with adaptive traits or speciation or testing for the signature of natural selection across the genome. Information on regional rates of recombination, localization of inversion breakpoints distinguishing it from its sibling species D. persimilis, and known polymorphic markers may be useful in such studies. Here, we present a molecular linkage map of four of the five major chromosome arms of D. pseudoobscura. In doing so, we order and orient several sequence contig groups, localize the inversion breakpoints on chromosome 2 to intervals of 200 kilobases, and identify one error in the published sequence assembly. Our results show that regional recombination rates in D. pseudoobscura are much higher than in D. melanogaster and significantly higher even than in D. persimilis. Furthermore, we detect a non-significant positive correlation between recombination rate and published DNA sequence variation. Finally, the online Appendix presents 200 primer sequence pairs for molecular markers that can be used for mapping of quantitative trait loci, of which 125 are known to be polymorphic within or between species.
七十多年来，进化生物学家一直在深入研究拟暗果蝇。最近公布的基因组序列不仅有助于与其他双翅目昆虫进行比较基因组学研究，还为识别与适应性性状或物种形成相关的基因或检测全基因组自然选择的特征打开了大门。有关区域重组率、将其与其姊妹物种拟果蝇区分开来的倒位断点定位以及已知多态性标记的信息可能在此类研究中有用。在此，我们展示了拟暗果蝇五条主要染色体臂中四条的分子连锁图谱。在此过程中，我们对几个序列重叠群进行了排序和定向，将2号染色体上的倒位断点定位到200千碱基的区间，并在已发表的序列组装中发现了一个错误。我们的结果表明，拟暗果蝇的区域重组率远高于黑腹果蝇，甚至显著高于拟果蝇。此外，我们检测到重组率与已发表的DNA序列变异之间存在不显著的正相关。最后，在线附录提供了200对用于分子标记的引物序列对，可用于数量性状位点的定位，其中125对已知在物种内或物种间具有多态性。
