Comparative physical mapping links conservation of microsynteny to chromosome structure and recombination in grasses
Comparative physical mapping links conservation of microsynteny to chromosome structure and recombination in grasses
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DOI：
10.1073/pnas.0502365102
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发表时间：
2005-09-13
影响因子：
11.1
通讯作者：
Paterson, AH
中科院分区：
文献类型：
--
作者：
Bowers, JE;Arias, MA;Paterson, AH
几乎完成的模式生物序列提供了一个基础，从其中探索其他分类群体之间的基因组多样性。我们探索水稻序列和两个高粱物理图谱，整合遗传标记，细菌人工染色体（BAC）指纹和BAC杂交数据之间的全基因组微共线性模式。高粱图谱大部分平铺基因组成分，含有41%的BAC，但80%的单拷贝基因，显示保守的微共线性与水稻和部分平铺非共线性成分，含有46%的BAC，但只有13%的单拷贝基因。其余的BAC是着丝粒的（4%）或未分配的（8%）。这两个基因组成分对应于细胞学上可辨别的“常染色质”和“异染色质”。“基因和重复DNA分布支持这种分类。更大的microcoolinearity在recombinogenic（常染色质）比nonrecombinogenic（异染色质）地区是一致的假设，基因组重排通常是有害的，因此更有可能坚持在nonrecombinogenic地区凭借穆勒的棘轮。染色体间的着丝粒重排可能促进了多倍体谷类祖先的二倍体化。模式植物序列能更好地指导重组基因组的相关研究。高粱BAC重叠群桥接水稻序列中的35个物理缺口，说明了至少在谷类甚至更广泛的比较方法的互惠互利。
Nearly finished sequences for model organisms provide a foundation from which to explore genomic diversity among other taxonomic groups. We explore genome-wide microsynteny patterns between the rice sequence and two sorghum physical maps that integrate genetic markers, bacterial artificial chromosome (BAC) fingerprints, and BAC hybridization data. The sorghum maps largely tile a genomic component containing 41% of BACs but 80% of single-copy genes that shows conserved microsynteny with rice and partially tile a nonsyntenic component containing 46% of BACs but only 13% of single-copy genes. The remaining BACs are centromeric (4%) or unassigned (8%). The two genomic components correspond to cytologically discernible "euchromatin" and "heterochromatin." Gene and repetitive DNA distributions support this classification. Greater microcolinearity in recombinogenic (euchromatic) than nonrecombinogenic (heterochromatic) regions is consistent with the hypothesis that genomic rearrangements are usually deleterious, thus more likely to persist in nonrecombinogenic regions by virtue of Muller's ratchet. Interchromosomal centromeric rearrangements may have fostered diploidization of a polyploid cereal progenitor. Model plant sequences better guide studies of related genomes in recombinogenic than nonrecombinogenic regions. Bridging of 35 physical gaps in the rice sequence by sorghum BAC contigs illustrates reciprocal benefits of comparative approaches that extend at least across the cereals and perhaps beyond.