Puro J
Mutat Res. 1985 Apr;149(2):179-87. doi: 10.1016/0027-5107(85)90024-7.
A cytological analysis of 22 and 7 autosomal (2;3) translocations induced, respectively, in mature and immature oocytes of Drosophila melanogaster appeared to be random in the distribution of the breaks. This finding is contrary to that expected if, as suggested by the mechanism of directed disjunction, the chromosomes involved in interchange at the centric region tended to be distributed to opposite poles at division I of meiosis. In each arm, the breaks were distributed more or less at random between the centromere and the telomere. However, in the translocations from the immature oocytes, the break-telomere distances of the segments interchanged showed a positive correlation, indicating that translocations induced in meiotic prophase and having a highly disproportionate length of segments interchanged are prone to be eliminated at division II by non-random disjunction of heteromorphic dyads.
对分别在黑腹果蝇成熟和未成熟卵母细胞中诱导产生的22个和7个常染色体（2;3）易位进行的细胞学分析表明，断裂的分布似乎是随机的。这一发现与定向分离机制所暗示的情况相反，如果在着丝粒区域发生互换的染色体在减数分裂I期倾向于分布到相反的两极，那么预期情况并非如此。在每条臂中，断裂或多或少随机分布在着丝粒和端粒之间。然而，在从未成熟卵母细胞产生的易位中，互换片段的断裂-端粒距离呈正相关，这表明在减数分裂前期诱导产生且互换片段长度极不成比例的易位，在减数分裂II期容易通过异型二价体的非随机分离而被消除。
