Ganal M W, Broun P, Tanksley S D
Department of Plant Breeding and Biometry, Cornell University, Ithaca, New York 14853.
Genomics. 1992 Oct;14(2):444-8. doi: 10.1016/s0888-7543(05)80239-3.
A telomere-associated tandemly repeated DNA sequence of tomato, TGR I, has been used to map telomeres on the tomato RFLP linkage map. Mapping was performed by monitoring the segregation of entire arrays of TGR I from a segregating F2 population using pulsed-field gel electrophoresis (PFGE). With this strategy, four telomeres have been mapped to the ends of the short arm of chromosomes 9 and 12 and the long arms of chromosomes 5 and 11, using a saturated RFLP map of tomato containing approximately 1000 RFLP markers. In all four cases, the TGR I locus maps to the end of the chromosome, and the distance between the most distal single-copy RFLP marker and the telomeric TGR I locus was between 1.6 and 9.6 cM. This indicates that the region close to the telomeres does not show an excessive rate of recombination compared to other regions of the genome and that the RFLP map of tomato is essentially complete and covers the entire genome for all practical purposes. Additionally, the mapping technique presented here should be generally applicable to the mapping of other tandemly repeated DNA sequences.
番茄的一种端粒相关串联重复DNA序列TGR I已被用于在番茄RFLP连锁图谱上定位端粒。通过使用脉冲场凝胶电泳（PFGE）监测来自分离的F2群体的TGR I整个阵列的分离来进行定位。采用这种策略，利用包含约1000个RFLP标记的番茄饱和RFLP图谱，已将四个端粒定位到9号和12号染色体短臂末端以及5号和11号染色体长臂末端。在所有四种情况下，TGR I基因座都定位到染色体末端，最远端单拷贝RFLP标记与端粒TGR I基因座之间的距离在1.6至9.6厘摩之间。这表明与基因组的其他区域相比，靠近端粒的区域没有显示出过高的重组率，并且番茄的RFLP图谱在所有实际应用中基本上是完整的，覆盖了整个基因组。此外，这里介绍的定位技术应该普遍适用于其他串联重复DNA序列的定位。
