Institute of Plant Biology, University of Zurich, Zollikerstrasse 107, Zurich, Switzerland.
Funct Integr Genomics. 2011 Dec;11(4):671-7. doi: 10.1007/s10142-011-0240-5. Epub 2011 Aug 2.
Powdery mildew of wheat (Triticum aestivum L.) is caused by the ascomycete fungus Blumeria graminis f.sp. tritici. Genomic approaches open new ways to study the biology of this obligate biotrophic pathogen. We started the analysis of the Bg tritici genome with the low-pass sequencing of its genome using the 454 technology and the construction of the first genomic bacterial artificial chromosome (BAC) library for this fungus. High-coverage contigs were assembled with the 454 reads. They allowed the characterization of 56 transposable elements and the establishment of the Blumeria repeat database. The BAC library contains 12,288 clones with an average insert size of 115 kb, which represents a maximum of 7.5-fold genome coverage. Sequencing of the BAC ends generated 12.6 Mb of random sequence representative of the genome. Analysis of BAC-end sequences revealed a massive invasion of transposable elements accounting for at least 85% of the genome. This explains the unusually large size of this genome which we estimate to be at least 174 Mb, based on a large-scale physical map constructed through the fingerprinting of the BAC library. Our study represents a crucial step in the perspective of the determination and study of the whole Bg tritici genome sequence.
小麦白粉病（Triticum aestivum L.）是由子囊菌真菌禾本科布氏白粉菌引起的。基因组方法为研究这种专性生物营养病原体的生物学开辟了新的途径。我们从使用 454 技术对其基因组进行低通量测序和构建该真菌的第一个基因组细菌人工染色体（BAC）文库开始分析 Bg tritici 基因组。使用 454 读数组装了高覆盖率的 contigs。它们允许鉴定 56 个转座元件，并建立 Blumeria 重复数据库。BAC 文库包含 12,288 个克隆，平均插入大小为 115kb，代表基因组的最大 7.5 倍覆盖。BAC 末端测序生成了 12.6Mb 的随机序列，代表基因组。BAC 末端序列分析表明，转座元件大量入侵，至少占基因组的 85%。这解释了这个基因组异常大的原因，我们根据通过 BAC 文库指纹图谱构建的大规模物理图谱，估计这个基因组至少有 174Mb。我们的研究代表了确定和研究整个 Bg tritici 基因组序列的重要一步。
