Campbell D A, Fogel S
Genetics. 1977 Apr;85(4):573-85. doi: 10.1093/genetics/85.4.573.
Experiments designed to characterize the association between disomic chromosome loss and centromere-adjacent mitotic recombination were performed. Mitotic gene convertants were selected at two heteroallelic sites on the left arm of disomic chromosome III and tested for coincident chromosome loss. The principal results are: (1) Disomic chromosome loss is markedly enhanced (nearly 40-fold) over basal levels among mitotic gene convertants selected to arise close to the centromere; no such enhancement is observed among convertants selected to arise relatively far from the centromere. (2) Chromosome loss is primarily associated with proximal allele conversion at the centromere-adjacent site, and many of these convertants are reciprocally recombined in the adjacent proximal interval. (3) Partial aneuploid exceptions provisionally identified as carrying left arm telocentrics have been found. A testable model is proposed suggesting that centromere involvement in genetic recombination may precipitate segregational disfunction leading to mitotic chromosome loss.
开展了旨在表征二体染色体丢失与着丝粒附近有丝分裂重组之间关联的实验。在二体Ⅲ号染色体左臂的两个杂合等位基因位点选择有丝分裂基因转化体，并检测其是否伴有染色体丢失。主要结果如下：（1）在选择靠近着丝粒产生的有丝分裂基因转化体中，二体染色体丢失比基础水平显著增强（近40倍）；在选择远离着丝粒产生的转化体中未观察到这种增强。（2）染色体丢失主要与着丝粒相邻位点的近端等位基因转化相关，并且许多这些转化体在相邻近端区间发生了相互重组。（3）已发现暂时鉴定为携带左臂端着丝粒的部分非整倍体异常情况。提出了一个可检验的模型，表明着丝粒参与遗传重组可能会引发分离功能障碍，导致有丝分裂染色体丢失。
