Fig. 2. The interaction of Star with Gl¹ is dosage sensitive. The chromosomal deficiency Df(2L)S3, which removes the Star locus, enhances the Gl¹ eye phenotype. (A) Gl¹ flies have a mild but distinct disarrangement of ommatidia. (B) Df(2L)S3 flies are near wild type in appearance. (C) By contrast, flies expressing both the deficiency and the Gl¹ mutation display an extreme rough-eye phenotype. The eye is small, narrow and very rough with a reduced number of ommatidia. (D) A recessive lethal allele of Glued, Gl^1-3 shows little or no interaction with the Star allele, S¹. By itself, S¹ has a slightly rough eye, as shown in Fig. 3A. (E) S¹ in combination with Gl¹ strongly enhances the rough-eye phenotype. (F) The enhancement is reverted to mildly rough eye by the presence of a Star transgene. Genotypes shown: (A) +/+; Gl¹/+, (B) Df(2L)S3/+; Gl¹/+, (C) Df(2L)S3/+; +/+, (D) S¹/+; Gl^1-3/+, (E) S¹/+; Gl¹/+, (F) S¹/+; P[hs-Star-HA]/Gl¹.