Bowers John E, Abbey Colette, Anderson Sharon, Chang Charlene, Draye Xavier, Hoppe Alison H, Jessup Russell, Lemke Cornelia, Lennington Jennifer, Li Zhikang, Lin Yann-Rong, Liu Sin-Chieh, Luo Lijun, Marler Barry S, Ming Reiguang, Mitchell Sharon E, Qiang Dou, Reischmann Kim, Schulze Stefan R, Skinner D Neil, Wang Yue-Wen, Kresovich Stephen, Schertz Keith F, Paterson Andrew H
Plant Genome Mapping Laboratory, University of Georgia, Athens, Georgia 30602, USA.
Genetics. 2003 Sep;165(1):367-86. doi: 10.1093/genetics/165.1.367.
We report a genetic recombination map for Sorghum of 2512 loci spaced at average 0.4 cM ( approximately 300 kb) intervals based on 2050 RFLP probes, including 865 heterologous probes that foster comparative genomics of Saccharum (sugarcane), Zea (maize), Oryza (rice), Pennisetum (millet, buffelgrass), the Triticeae (wheat, barley, oat, rye), and Arabidopsis. Mapped loci identify 61.5% of the recombination events in this progeny set and reveal strong positive crossover interference acting across intervals of </=50 cM. Significant variations in DNA marker density are related to possible centromeric regions and to probable chromosome structural rearrangements between Sorghum bicolor and S. propinquum, but not to variation in levels of intraspecific allelic richness. While cDNA and genomic clones are similarly distributed across the genome, SSR-containing clones show different abundance patterns. Rapidly evolving hypomethylated DNA may contribute to intraspecific genomic differentiation. Nonrandom distribution patterns of multiple loci detected by 357 probes suggest ancient chromosomal duplication followed by extensive rearrangement and gene loss. Exemplifying the value of these data for comparative genomics, we support and extend prior findings regarding maize-sorghum synteny-in particular, 45% of comparative loci fall outside the inferred colinear/syntenic regions, suggesting that many small rearrangements have occurred since maize-sorghum divergence. These genetically anchored sequence-tagged sites will foster many structural, functional and evolutionary genomic studies in major food, feed, and biomass crops.
我们报道了一个高粱的遗传重组图谱，该图谱基于2050个RFLP探针，有2512个位点，平均间隔为0.4厘摩（约300千碱基对），其中包括865个异源探针，这些探针有助于甘蔗、玉米、水稻、狼尾草、小麦族（小麦、大麦、燕麦、黑麦）和拟南芥的比较基因组学研究。定位的位点识别出了该后代群体中61.5%的重组事件，并揭示了在小于等于50厘摩的区间上存在强烈的正向交叉干扰。DNA标记密度的显著差异与可能的着丝粒区域以及双色高粱和近缘高粱之间可能的染色体结构重排有关，但与种内等位基因丰富度水平的变化无关。虽然cDNA和基因组克隆在基因组中分布相似，但含SSR的克隆显示出不同的丰度模式。快速进化的低甲基化DNA可能有助于种内基因组分化。357个探针检测到的多个位点的非随机分布模式表明存在古老的染色体复制，随后是广泛的重排和基因丢失。为了证明这些数据对于比较基因组学的价值，我们支持并扩展了之前关于玉米 - 高粱同线性的研究结果——特别是，45%的比较位点落在推断的共线/同线区域之外，这表明自玉米 - 高粱分化以来发生了许多小的重排。这些基于遗传定位的序列标签位点将促进主要粮食、饲料和生物质作物的许多结构、功能和进化基因组学研究。
