TABLE 4

Segregation data of the sex chromosomes at meiosis I and meiosis II in X/Y males

Second or third
chromosome genotype
Sperm classes
XY(Y)XY(Y)XXXXY(Y)OTotal% ND
+/+37853552300573450.1
mei(2)yh92/mei(2)yh922696271735973471625313.4
mei(2)yh92/CyO3653373510101574140.4
mei(3)M20/mei(3)M204934583536310334171143.8
mei(3)M20/DcxF766757000215250.1
mei(2)yoh7134/mei(2)yoh7134424449900108922.1
mei(2)yh149/mei(2)yh1491094101104a01221210.8
mei(2)yh217/mei(2)yh21746293518530017083702.7
mei(2)yh217/CyO18381763000136020.0
  • y w/y+Y males were individually crossed to C(1)RM, y v f/O females. CyO and DcxF are balancers. The possible presence of multiple doses of the Y chromosome that cannot be distinguished phenotypically is shown in parentheses in the sperm genotypes. ND, nondisjunction.

  • a These four females may be rare surviving metafemales or triploids [C(1)RM/X], instead of meiosis II nondisjunctional females (X/X/O). These two classes of flies were not distinguishable phenotypically, because y w+/y+Y males, instead of y w/y+Y males, were used in this particular cross.