Fig. 4. Star is required for suppression of Gl¹ by Dhc alleles. Epistasis tests were carried out by examining different mutant combinations using SEM. Representative examples of (A) the Gl¹ eye, and (B) the Gl¹ eye enhanced by S¹, are shown to allow comparisons. (C) Su(Gl)77, a mutation in the Dhc locus, partially suppresses the Gl¹ dominant eye phenotype. Dhc^8-1 similarly suppresses the Gl¹ rough eye (not shown). (D) The mutation in Star overcomes the suppression effect of the Dhc allele Su(Gl)77, and results in an enhanced Gl¹ phenotype. The same result (not shown) is seen with Dhc^8-1 in the presence of Gl¹ and S¹. (E) Su(Gl)77 in combination with Dhc^8-1 completely suppresses the Gl¹ eye phenotype. (F) Despite the presence of two Dhc mutations that suppress Gl¹, S¹ still shows enhancement of the Gl¹ rough eye. Genotypes shown: (A) +/+; Gl¹/+, (B) S¹/+; Gl¹/+, (C) Su(Gl)77 Gl¹/+, (D) S¹/+; Su(Gl)77 Gl¹/+, (E) +/+; Su(Gl)77 Gl¹/Dhc^8-1, (F) S¹/+; Su(Gl)77 Gl¹/Dhc^8-1.