Yüksel B, Paterson A H
Plant Genome Mapping Lab, The University of Georgia, 111 Riverbend Road, Athens, GA 30605, USA.
Theor Appl Genet. 2005 Aug;111(4):630-9. doi: 10.1007/s00122-005-1992-x. Epub 2005 Jul 28.
Bacterial artificial chromosome (BAC) libraries have been an essential tool for physical analyses of genomes of many crops. We constructed and characterized the first large-insert DNA library for Arachis hypogaea L. The HindIII BAC library contains 182,784 clones; only 5,484 (3%) had no inserts; and the average insert size is 104.05 kb. Chloroplast DNA contamination was very low, only nine clones, and r-DNA content was 1,208, 0.66% of clones. The depth of coverage is estimated to be 6.5 genome-equivalents, allowing the isolation of virtually any single-copy locus. This rate of coverage was confirmed with the application of 20 overgos, which identified 305 positive clones from the library. The identification of multiple loci by most probes in polyploids complicates anchoring of physical and genetic maps. We explored the practicality of a hybridization-based approach for determination of map locations of BAC clones in peanut by analyzing 94 clones detected by seven different overgos. The banding patterns on Southern blots were good predictors of contig composition; that is, the clones that shared the same size bands and ascribed to the same overgos usually also located in the same contigs. This BAC library has great potential to advance future research about the peanut genome.
细菌人工染色体（BAC）文库一直是许多作物基因组物理分析的重要工具。我们构建并鉴定了首个花生（Arachis hypogaea L.）的大插入片段DNA文库。该HindIII BAC文库包含182,784个克隆；只有5,484个（3%）没有插入片段；平均插入片段大小为104.05 kb。叶绿体DNA污染非常低，只有9个克隆，r-DNA含量为1,208个克隆，占克隆总数的0.66%。估计覆盖深度为6.5个基因组当量，几乎可以分离任何单拷贝基因座。通过应用20个重叠群证实了这种覆盖速率，从文库中鉴定出305个阳性克隆。多倍体中大多数探针鉴定多个基因座的情况使物理图谱和遗传图谱的锚定变得复杂。我们通过分析由7种不同重叠群检测到的94个克隆，探索了一种基于杂交的方法来确定花生中BAC克隆图谱位置的实用性。Southern杂交上的条带模式是重叠群组成的良好预测指标；也就是说，共享相同大小条带且归属于相同重叠群的克隆通常也位于相同的重叠群中。这个BAC文库在推进未来花生基因组研究方面具有巨大潜力。
