Fig. 4. Lateral inhibition and interommatidial spacing function in Bar loss-of-function clones. Bar loss-of-function clones were identified by the absence of anti-GFP staining and marked with broken lines in C,F. Sens (A-C) and dpERK (D-F) staining within the furrow were normal with regular spacing in Bar mutant regions. White and yellow arrows mark R8 equivalence groups in the wild-type and the Bar mutant regions, respectively.