Fig. 7. Altered gene expression in At-Delta RNAi embryos in Achaearanea. (A-D) Staining for At-fkh transcripts. (A,B) Untreated (A) and At-Delta^HH RNAi (B) germ discs at stage 5. CM cells are indicated by arrows. The number of At-fkh-expressing cells at the periphery of the At-Delta^HH RNAi germ disc is largely reduced. (C,D) gfp (C) and At-Delta^EB (D) RNAi germ discs at stage 6. At-fkh-expressing cells are seen in central and peripheral areas. The dark areas indicated by arrows in D are due to thick folds of the cell sheet, not significant signals. (E-H) gfp (E,G) and At-Delta^EB (F,H) RNAi embryos at late stage 6 stained for At-twi (E,F) or At-cad (G,H) transcripts. The emerging caudal region is indicated by brackets in C-H. In At-Delta^EB RNAi embryos, At-twi-expressing cells were overproduced at the expense of At-cad-expressing cells. (I-N) gfp (I,K,M) and At-Delta^EB (J,L,N) RNAi embryos at early germ band stage (stage 8) stained for At-twi (I,J) or At-hh (K,L) transcripts, or for cell death (M,N). The caudal region of At-Delta^EB RNAi germ bands was grossly affected. In K and L, dots indicate segments corresponding to the four pairs of walking legs. In M and N, arrowheads indicate the anterior and posterior ends of the germ band. Anterior is to the top in C-N. Scale bars: 100 µm.