Maddern R H, Leigh B
Mutat Res. 1976 Dec;41(2-3):255-68. doi: 10.1016/0027-5107(76)90099-3.
Drosophila melanogaster males with marked X and Y chromosomes were irradiated, and mature sperm sampled by mating the males to females carrying attached-X chromosomes. Induced loss and partial loss of the paternal sex chromosomes was studied. F1 females were scored according to their phenotype, and transmitted fragments were analyzed genetically. Half of the exceptional F1 females could be scored as "partial losses". Of the apparent total loss exceptions, which were tested, half were carrying detectable fragments. 21% of the transmissible fragments is an under-estimate because only 6 of the 10 chromosome tips were marked in such a way that duplications could be detected. In addition, the markers used were located near, but not at, the chromosome ends. These data are interpreted as indicating that a high proportion of the chromosome loss and partial loss, induced by irradiation of mature sperm, is a consequence of chromatid rearrangements arising from chromosome breaks which stay open until replication. It is suggested that, during the transition from sperm head to mature pronucleus, repair of breaks and chromosome replication are two processes that occur in overlapping time intervals. It is therefore possible for chromosome breaks induced in mature sperm to give rise to chromosome and chromatid rearrangements.
对带有标记X和Y染色体的黑腹果蝇雄性进行辐照，通过将这些雄性与携带并连X染色体的雌性交配来采集成熟精子。研究了父本性染色体的诱导丢失和部分丢失情况。根据F1雌性的表型进行评分，并对传递的片段进行遗传分析。一半的异常F1雌性可被判定为“部分丢失”。在对明显的完全丢失异常进行检测时，其中一半携带可检测到的片段。21%的可传递片段是一个低估数字，因为10个染色体末端中只有6个以能够检测到重复的方式进行了标记。此外，所使用的标记位于染色体末端附近而非末端。这些数据被解释为表明，成熟精子辐照诱导的染色体丢失和部分丢失中，很大一部分是由染色体断裂导致的染色单体重排造成的，这些断裂在复制前一直处于开放状态。有人提出，在从精子头部向成熟原核转变的过程中，断裂修复和染色体复制是在重叠的时间间隔内发生的两个过程。因此，成熟精子中诱导产生的染色体断裂有可能导致染色体和染色单体重排。
