Fig. 6.

l(1)sc activates H-cell gene expression. Horizontal views of single segments of stage 14-16 embryos. (A) Wild-type, (B-H) sim-Gal4 UAS-l(1)sc and (I) sim-Gal4 UAS-sc embryos stained for ple expression (green) and various H-cell-expressed genes (magenta). All embryos were sim-Gal4 UAS-tau-GFP and were stained for GFP (blue). (A) The single wild-type ple⁺ H-cell. (B-B″) Misexpression of l(1)sc resulted in two ple⁺ cells in 18% of segments scored. One cell was the H-cell (white arrow), and the additional cell was CG13565⁺ (magenta; yellow arrow), which indicated that it was the H-cell sib. (C-G) Misexpression of l(1)sc resulted in the appearance of (C) BarH1, (D) DAT, (E) NPFR1, (F) SoxN and (G) Tup in an additional ple⁺ cell in 14-24% of segments scored. (H) Misexpression of l(1)sc resulted in the expansion of Vmat expression from four cells in wild type to five to eight cells. In this segment, there were five Vmat⁺ cells, two of which were ple⁺ (arrowheads; H-cell and H-cell sib) and the other three were mVUMs (arrows; only two Vmat⁺ mVUMs appear in this focal plane). (I) Misexpression of sc had no affect on ple or tup expression; only H-cell expression was observed.