Gregor Mendel Institute, Austrian Academy of Sciences, Vienna, Austria.
Molecular and Computational Biology, University of Southern California, Los Angeles, California, USA.
Nat Genet. 2013 Aug;45(8):884-890. doi: 10.1038/ng.2678. Epub 2013 Jun 23.
Despite advances in sequencing, the goal of obtaining a comprehensive view of genetic variation in populations is still far from reached. We sequenced 180 lines of A. thaliana from Sweden to obtain as complete a picture as possible of variation in a single region. Whereas simple polymorphisms in the unique portion of the genome are readily identified, other polymorphisms are not. The massive variation in genome size identified by flow cytometry seems largely to be due to 45S rDNA copy number variation, with lines from northern Sweden having particularly large numbers of copies. Strong selection is evident in the form of long-range linkage disequilibrium (LD), as well as in LD between nearby compensatory mutations. Many footprints of selective sweeps were found in lines from northern Sweden, and a massive global sweep was shown to have involved a 700-kb transposition.
尽管测序技术取得了进步，但要全面了解人群中的遗传变异，这个目标仍远未实现。我们对来自瑞典的 180 条拟南芥进行了测序，以尽可能完整地描绘单一区域的变异情况。虽然基因组独特部分的简单多态性很容易识别，但其他多态性则不然。流式细胞术鉴定的基因组大小的巨大变异似乎主要是由于 45S rDNA 拷贝数的变异，来自瑞典北部的品系具有特别多的拷贝数。长程连锁不平衡（LD）以及附近补偿性突变之间的 LD，表明选择作用非常明显。在来自瑞典北部的品系中发现了许多选择清除的痕迹，并且一个大规模的全球清除事件表明涉及到 700kb 的转座。
