On nature of Y chromosome fragments induced in Drosophila melanogaster females. III. C(1)RA vs C(1)RM females.

The distribution of breakpoints in the Y chromosome has been determined for samples of Y chromosome fragments recovered from irradiated immature and mature oocytes of females carrying a reversed acrocentric compound X chromosome. Both distributions differ from the distributions determined from Y chromosome fragments recovered from irradiated females carrying a reversed metacentric compound X chromosome. Differential spatial associations of chromosomes in the oocyte nuclei of the two types of females is discussed as a possible cause of the observed differences.