Wolff D J, Schwartz S
Department of Obstetrics and Gynecology, University of Maryland School of Medicine, Baltimore.
Hum Mol Genet. 1993 Jun;2(6):693-9. doi: 10.1093/hmg/2.6.693.
To test the hypothesis that Robertsonian translocation may lead to altered crossing-over on both chromosomes involved in the rearrangement (intrachromosomal effects) and other chromosomes in the cell (interchromosomal effects), we initiated this pilot study utilizing molecular markers (RFLPs) to determine the frequency and approximate location of crossovers on chromosomes 21 of human Robertsonian translocation carriers. Analysis of intrachromosomal effects in five families with Robertsonian translocations involving a chromosome 21 demonstrated an elevation in the amount of crossing-over on chromosomes 21 of the female translocation parent. Several of the crossovers were localized proximal to 21q21.2, suggesting that Robertsonian translocations may lead to an alteration of both the frequency and location of crossing-over. In an assessment of interchromosomal effects in five additional families with a non-21 Robertsonian translocation, no effect could be demonstrated on chromosome 21. The initial data imply that Robertsonian translocation influences the number and position of exchanges on chromosomes 21 involved in the rearrangement, which may be associated with an increased tendency for nondisjunction due to prolonged synapsis of 21. This pilot study demonstrates the utility of this approach in the assessment of intra- and interchromosomal effects of Robertsonian translocations on recombination.
为了验证罗伯逊易位可能导致参与重排的两条染色体（染色体内效应）以及细胞中其他染色体（染色体间效应）上的交叉互换发生改变这一假说，我们开展了这项初步研究，利用分子标记（限制性片段长度多态性，RFLP）来确定人类罗伯逊易位携带者21号染色体上交叉互换的频率和大致位置。对五个涉及21号染色体的罗伯逊易位家族的染色体内效应分析表明，女性易位亲本的21号染色体上交叉互换的数量有所增加。其中一些交叉互换定位在21q21.2近端，这表明罗伯逊易位可能导致交叉互换的频率和位置发生改变。在对另外五个具有非21号罗伯逊易位家族的染色体间效应评估中，未发现对21号染色体有影响。初步数据表明，罗伯逊易位会影响参与重排的21号染色体上交换的数量和位置，这可能与由于21号染色体长时间联会导致的不分离倾向增加有关。这项初步研究证明了这种方法在评估罗伯逊易位对重组的染色体内和染色体间效应方面的实用性。
