TABLE 1

Genetic interactions between AR2 and naked

0 belts0.5–4 belts4.5–7.5 belts
CrossNo. of
 nkd
 mutantsObserved%
 observed%
 expectedObserved%
 observed%
 expectedObserved%
 observed%
 expected
1. nkd/+ × nkd/+124 8 6 011391100 3 2 0
2. AR2/+;nkd/+ ×
     AR2/+;nkd/+26586322517566 75 4 2 0
3. wg/+;nkd/+ × nkd/+118 8 7 0 5345 50574850
4. wg AR2/++;nkd/+ ×
     AR2/+;nkd/+30264212517056 50672225
  • Only nkd homozygous-mutant embryos are categorized; these represented ∼25% of the total fertilized eggs laid in each cross. Expected percentages for crosses 2 and 4 are based on our hypothesis that AR2 homozygosity enhances the severity of the nkd mutant phenotype. Expected percentages for cross 3 are based on previous observations that wg heterozygosity suppresses the nkd mutant phenotype (Bejsovec and Wieschaus 1993). Note that variability in the nkd single-mutant phenotype (cross 1) accounts for the divergence between observed and expected frequencies in crosses 2 and 3; when this is taken into consideration, the observed and expected numbers are not significantly different. This does not appear to be true for cross 4, suggesting that reduced wg gene dose slightly diminishes the ability of RacGap50C mutations to enhance the nkd mutant phenotype.