FIG. 5.

Reduced Src, Btk29A, and bsk function suppresses the dCsk phenotype. (A) Genetic interactions between dCsk^j1D8/S030003 and candidate effector genes. Control dCsk^j1D8/S030003 animals were grown alongside each experimental group. Observed pharate adults are included in the total count of dead pupae. Results for dCsk controls are presented as ranges observed in separate groups of animals (>35 animals per control group). The bsk² allele was tested and displayed an effect similar to that of bsk¹ (data not shown). dEgfr encodes the epidermal growth factor receptor ortholog; Sos encodes a Ras GTPase exchange factor; Jra encodes the c-jun ortholog; chico encodes the insulin receptor substrate ortholog; ft, CadN, and shg encode cadherin orthologs; and scb encodes an α-integrin subunit. The dEgfr, Sos, Jra, and ft alleles used are nulls, and the chico, Btk29A, Src64B, bsk, Src42A¹⁸-², Src42A^Su1, CadN, and scb alleles used are strong hypomorphs. The dEgfr, Sos, and Jra alleles are all known genetic modifiers of receptor tyrosine kinase and Ras pathways (21, 39). ND, not determined. (B and C) FACS analysis for DNA content of eye-antennal imaginal disc cells (B) and wing imaginal discs (C) from wild-type (WT) (dashed grey), dCsk^j1D8/S030003 (pink), Btk29A^k00206/+; dCsk^j1D8/S030003 (blue), and bsk¹/+; dCsk^j1D8/S030003 (green) 128-h-AED larvae. (D) Photographs of adult flies demonstrating that Btk29A^k00206 and bsk¹ mutations rescue dCsk^j1D8/S030003 mutants. The fly on the far right is a rare dCsk^j1D8/S030003 pharate adult; note the curled legs, the uninflated wings, and the slightly enlarged eye.