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Fig. 3. Ectopic Ato+ cells form photoreceptor clusters. Bar
loss-of-function clones were identified by the absence of GFP (A-I, green) or
BarH1 (J-O, green) staining and marked with broken lines in C,F,I,L,O. (A-I)
Ectopic Ato+ cells further differentiate into mature R8
photoreceptor cells within Bar loss-of-function clones. The number of
cells expressing Sca (A-C; early R8 marker), Sens (D-F; early R8 marker) and
Boss (G-I; late R8 marker) was increased within the clones. (J-O) Excess
numbers of ommatidial clusters are formed in Bar loss-of-function
clones. Photoreceptor clusters were detected by Elav (J-L) or Arm (M-O)
staining. The size of some clusters within the Bar mutant clone was
smaller than that of the wild-type ommatidia clusters, suggesting that
photoreceptor recruitment in these ectopic clusters is not yet complete. White
and yellow arrows in O indicate normal or ectopic photoreceptor clusters,
respectively.