Cochran D G
Chromosoma. 1976 Dec 16;59(2):129-35. doi: 10.1007/BF00328481.
Adjacent-1, alternate-1, adjacent-2, and alternate-2 disjunction configurations were observed cytologically at metaphase I in heterozygotes from two reciprocal chromosome translocations in the German cockroach, Blattella germanica (L.). T(7; 12) shows random disjunction and the frequencies of the above four types were in a ratio of 2:1:1:2 (p greater than 0.90). T(3; 12) has directed disjunction (about 70% alternate) which is attributable to a heavy preponderance of alternate-2. No interpretable ratio occurs here except for the equality of alternate-1 and adjacent-2 types. These observations confirm the existence of two types of alternate disjunction, and provide insight into the basis for random vs directed disjunction.
在德国小蠊（Blattella germanica (L.)）的两个相互染色体易位杂合子的减数第一次分裂中期，通过细胞学观察到了邻接-1、相间-1、邻接-2和相间-2分离构型。T(7; 12)表现出随机分离，上述四种类型的频率比例为2:1:1:2（p大于0.90）。T(3; 12)具有定向分离（约70%为相间型），这归因于相间-2的大量优势。除了相间-1和邻接-2类型相等外，这里没有可解释的比例。这些观察结果证实了两种相间分离类型的存在，并为随机分离与定向分离的基础提供了见解。
