Laboratory of Plant Cytogenetics, Department of Botany, Federal University of Pernambuco, Recife, PE, 50670-420, Brazil.
Chromosome Res. 2010 Jun;18(4):487-502. doi: 10.1007/s10577-010-9129-8. Epub 2010 May 7.
A cytogenetic map of common bean was built by in situ hybridization of 35 bacterial artificial chromosomes (BACs) selected with markers mapping to eight linkage groups, plus two plasmids for 5S and 45S ribosomal DNA and one bacteriophage. Together with three previously mapped chromosomes (chromosomes 3, 4, and 7), 43 anchoring points between the genetic map and the cytogenetic map of the species are now available. Furthermore, a subset of four BAC clones was proposed to identify the 11 chromosome pairs of the standard cultivar BAT93. Three of these BACs labelled more than a single chromosome pair, indicating the presence of repetitive DNA in their inserts. A repetitive distribution pattern was observed for most of the BACs; for 38% of them, highly repetitive pericentromeric or subtelomeric signals were observed. These distribution patterns corresponded to pericentromeric and subtelomeric heterochromatin blocks observed with other staining methods. Altogether, the results indicate that around half of the common bean genome is heterochromatic and that genes and repetitive sequences are intermingled in the euchromatin and heterochromatin of the species.
构建了普通菜豆的细胞遗传学图谱，该图谱通过对 35 个细菌人工染色体（BAC）进行原位杂交获得，这些 BAC 是根据定位在 8 个连锁群上的标记选择的，此外还有两个用于 5S 和 45S 核糖体 DNA 的质粒和一个噬菌体。加上之前已定位的三个染色体（第 3、4 和 7 号染色体），现在共有 43 个遗传图谱和物种细胞遗传学图谱之间的锚定位点。此外，还提出了一组四个 BAC 克隆子集，以鉴定标准品种 BAT93 的 11 对染色体。这三个 BAC 标记了不止一对染色体，表明它们的插入物中存在重复 DNA。大多数 BAC 都观察到重复的分布模式；对于其中 38%的 BAC，可以观察到高度重复的着丝粒或端粒周围信号。这些分布模式与用其他染色方法观察到的着丝粒和端粒异染色质块相对应。总的来说，这些结果表明，普通菜豆基因组的约一半是异染色质，并且基因和重复序列在该物种的常染色质和异染色质中交织在一起。
