Tease C, Fisher G
M.R.C. Radiobiology Unit, Didcot, Oxon, UK.
Chromosoma. 1989 Jan;97(4):315-20. doi: 10.1007/BF00371972.
Pachytene oocytes from foetal mice heterozygous for the translocation T(14; 15)6Ca were screened for evidence of a "production-line" effect on chromosome pairing. Metaphase I oocytes from adult heterozygotes were also examined to determine whether any such effect on pahytene chromosome pairing is subsequently repeated during adult reproductive life as anticipated by the production-line hypothesis. It was found that as gestation proceeded the proportion of pachytene oocytes with a translocation quadrivalent declined and that with a trivalent and univalent correspondingly increased. That is, there was evidence of variation in pairing behaviour of the translocation at different times of gestation. In contrast, the proportions of metaphase I cells with either a quadrivalent or a trivalent plus univalent did not vary between adult females of different ages. Thus if the variation observed at pachytene was the result of a production-line effect, clearly this was not reflected in the behaviour of the translocation at metaphase I. Our observations therefore do not support the production-line hypothesis for the maternal age effect on nondisjunction.
对易位T(14; 15)6Ca杂合的胎鼠粗线期卵母细胞进行筛选，以寻找染色体配对中“生产线”效应的证据。还对成年杂合子的中期I卵母细胞进行了检查，以确定粗线期染色体配对上的任何此类效应是否如生产线假说所预期的那样在成年生殖期随后再次出现。结果发现，随着妊娠的进行，具有易位四价体的粗线期卵母细胞比例下降，具有三价体和单价体的比例相应增加。也就是说，有证据表明在妊娠不同时期易位的配对行为存在差异。相比之下，不同年龄成年雌性中期I细胞中具有四价体或三价体加单价体的比例没有变化。因此，如果在粗线期观察到的变异是生产线效应的结果，显然这在中期I的易位行为中没有体现。因此，我们的观察结果不支持关于母龄对不分离影响的生产线假说。
