Table 2 Sister chromatid vs. homolog NDJ in sunn mutant males
Sperm genotype
Progeny phenotype
Paternal genotypew B+su-wa BSw BSw B+su-wa B+na%NDJb%sisc
Total sunn1010687631170808330653.835.0
Gamete frequency (%)30.620.819.15.124.4
Df/+ (WT)73048901112210.31
  • w/BSYy+ males with the indicated third chromosome genotype for sunn were each crossed to two C(1)RM, y2 su (wa) wa/O females. These females produce only diplo-X and nullo-X eggs and permit recovery of viable progeny derived exclusively from sister chromatid NDJ sperm (XX), homolog NDJ sperm (XY), and nullo-XY (O) sperm (which result from both types of NDJ). The diplo-X eggs yield viable progeny when fertilized by Y or nullo-XY (O) sperm. These progeny exhibit a suppressed white-apricot (light brown) eye color (su-wa) caused by the su (wa) and wa alleles on C(1)RM. The nullo-X eggs yield viable progeny when fertilized by X, XY, XX, or XXY sperm. These progeny all have white eyes because of the null w allele carried on the paternal X chromosome. Progeny were classified by sperm genotype as described above in column labels.

  • a Total number of progeny scored.

  • b % NDJ = 100 × ((2 × XX) + XY + O)/ n.

  • c % sister chromatid NDJ = 100 × (2 × XX)/ ((2 × XX) + XY).

  • Notes: (1) Progeny with one or two copies of BSYy+ cannot be discriminated, so some progeny scored as derived from Y or XY sperm could have been YY or XYY. (2) In the %NDJ and %sis formulae, the XX sperm-derived progeny are doubled to account for the YY sperm-derived progeny, which cannot be discriminated from regular Y sperm-derived progeny and are poorly viable. (3) Two, seven, and two progeny derived from XXY non-disjunctional sperm were recovered from sunnZ3-5839/Df, sunnZ3-1956/Df, and sunnZ3-4085/Df hemizygotes, respectively (not shown in table).