Carvalho Ana, Guedes-Pinto Henrique, Lima-Brito José
Institute of Biotechnology and Bioengineering, Centre of Genomics and Biotechnology,University of Tras-os-Montes and Alto Douro, PO Box 1013, 5001-801 Vila Real, Portugal.
J Genet. 2011 Aug;90(2):203-8. doi: 10.1007/s12041-011-0051-4.
The intergenic spacer of the ribosomal DNA is highly variable, but is location specific in the nucleolar organizer region of the chromosomes. This study provides an event of high level of polymorphism / size variation and occurrence of 14 unique phenotypes in 48 landraces of Portuguese bread wheat cultivars for IGS-amplified products obtained by PCR-RFLP technique performed with TaqI. The attendant IGS polymorphism has been used to deduce affinities between landraces. Some of the high molecular weight IGS allelic variants were also probed for their chromosomal localization by sequential silver nitrate staining and fluorescence in situ hybridization. However, only the intergenic spacer allelic variant of 3.1 kb could be successfully hybridized, and was observed to be physically located on the chromosome pair 1B in the NOR loci of the cultivar 'Magueija'.
核糖体DNA的基因间隔区高度可变，但在染色体的核仁组织区具有位置特异性。本研究通过用TaqI进行PCR-RFLP技术，对葡萄牙面包小麦品种的48个地方品种的IGS扩增产物，提供了高水平的多态性/大小变异事件以及14种独特表型的出现情况。伴随的IGS多态性已被用于推断地方品种之间的亲缘关系。还通过连续硝酸银染色和荧光原位杂交，对一些高分子量IGS等位基因变体进行了染色体定位探测。然而，只有3.1 kb的基因间隔区等位基因变体能够成功杂交，并观察到其物理位置在品种‘马圭亚’的1B染色体对的NOR位点上。
