otd is expressed in DL2a dopaminergic neurons in the larval brain. (A,C) otd (blue) is expressed in a specific cluster of TH-positive (red) DA neurons of the larval central brain during L1 (A) and L3 (C). (B,D) In ocγa1hemizygous larvae, two out of three DL2a DA neurons at L1 (B) and three out of four DL2a DA neurons at L3 (D) are not detected using anti-TH immunoreactivity. Scale bars: 10 μm (A,B); 20 μm (C,D). (E) The oc2 enhancer is active in three out of the four DL2a DA neurons at L3. Scale bar: 10 μm. (E
) otd expression and (E'
) oc2 enhancer activity in DL2a DA neurons are analyzed in individual optical sections. (E
) DL2b DA neurons display neither otd expression nor oc2 enhancer activity. Scale bars: 5 μm (E1-E4). (F,F
) In L3 ocγa1hemizygous larvae, oc2 enhancer activity in DL2a DA neurons is lost. Scale bar: 10 μm. (G) otdYH13mutant cell clones induced during early embryogenesis impair the development of DL2a DA neurons (white arrow). Yellow arrows point to the DL2b DA neurons in the left hemisphere Scale bar: 50 μm. All the panels, except for (E1-E4) and (E'1-E'4), represent Z projections of individual confocal optical sections. DA, dopaminergic; DL, dorso lateral; GFP, green fluorescent protein; L, instar larval stage; oc, ocelliless; otd, orthodenticle; TH, tyrosine hydroxylase.