Draye X, Lin Y R, Qian X Y, Bowers J E, Burow G B, Morrell P L, Peterson D G, Presting G G, Ren S X, Wing R A, Paterson A H
Applied Genetic Technology Center, Departments of Crop and Soil Science, Botany, and Genetics, University of Georgia, Athens, GA 30602, USA.
Plant Physiol. 2001 Mar;125(3):1325-41. doi: 10.1104/pp.125.3.1325.
The small genome of sorghum (Sorghum bicolor L. Moench.) provides an important template for study of closely related large-genome crops such as maize (Zea mays) and sugarcane (Saccharum spp.), and is a logical complement to distantly related rice (Oryza sativa) as a "grass genome model." Using a high-density RFLP map as a framework, a robust physical map of sorghum is being assembled by integrating hybridization and fingerprint data with comparative data from related taxa such as rice and using new methods to resolve genomic duplications into locus-specific groups. By taking advantage of allelic variation revealed by heterologous probes, the positions of corresponding loci on the wheat (Triticum aestivum), rice, maize, sugarcane, and Arabidopsis genomes are being interpolated on the sorghum physical map. Bacterial artificial chromosomes for the small genome of rice are shown to close several gaps in the sorghum contigs; the emerging rice physical map and assembled sequence will further accelerate progress. An important motivation for developing genomic tools is to relate molecular level variation to phenotypic diversity. "Diversity maps," which depict the levels and patterns of variation in different gene pools, shed light on relationships of allelic diversity with chromosome organization, and suggest possible locations of genomic regions that are under selection due to major gene effects (some of which may be revealed by quantitative trait locus mapping). Both physical maps and diversity maps suggest interesting features that may be integrally related to the chromosomal context of DNA-progress in cytology promises to provide a means to elucidate such relationships. We seek to provide a detailed picture of the structure, function, and evolution of the genome of sorghum and its relatives, together with molecular tools such as locus-specific sequence-tagged site DNA markers and bacterial artificial chromosome contigs that will have enduring value for many aspects of genome analysis.
高粱（Sorghum bicolor L. Moench.）的小基因组为研究如玉米（Zea mays）和甘蔗（Saccharum spp.）等亲缘关系较近的大基因组作物提供了重要模板，并且作为“禾本科基因组模型”，它是与亲缘关系较远的水稻（Oryza sativa）的合理补充。以高密度RFLP图谱为框架，通过将杂交和指纹数据与来自水稻等相关分类群的比较数据整合，并使用新方法将基因组重复解析为位点特异性组，正在构建一个强大的高粱物理图谱。利用异源探针揭示的等位基因变异，正在高粱物理图谱上插入小麦（Triticum aestivum）、水稻、玉米、甘蔗和拟南芥基因组上相应位点的位置。水稻小基因组的细菌人工染色体被证明可填补高粱重叠群中的几个缺口；新兴的水稻物理图谱和组装序列将进一步加速研究进展。开发基因组工具的一个重要动机是将分子水平的变异与表型多样性联系起来。“多样性图谱”描绘了不同基因库中的变异水平和模式，揭示了等位基因多样性与染色体组织的关系，并暗示了由于主要基因效应而处于选择之下的基因组区域的可能位置（其中一些可能通过数量性状位点定位揭示）。物理图谱和多样性图谱都显示出一些有趣的特征，这些特征可能与DNA的染色体背景密切相关——细胞学的进展有望提供一种阐明此类关系的方法。我们试图提供高粱及其亲缘植物基因组的结构、功能和进化的详细图景，以及诸如位点特异性序列标签位点DNA标记和细菌人工染色体重叠群等分子工具，这些工具将在基因组分析的许多方面具有持久价值。
