Fig. 3. Comparison of after eight^AR33 (aei^AR33) and aei^AR33; Tg(dlD:myc)kca⁵ embryos. (A,A') 14-somite stage embryos, arrows indicate the last formed somites. (A) aei^AR33 mutant. No normal somites form beyond the eighth somite. (A') aei^AR33; Tg(dlD:myc)kca⁵ embryos have normal somites. (B) Western blot loaded with protein extracts from 24 hpf embryos of different genotypes, probed with an anti-myc antibody. Lane 1, wild-type; lane 2, progeny of aei^AR33; Tg(dlD:myc)kca⁵ x wild type; lane 3, progeny of aei^AR33; Tg(dlD:myc)kca⁵ x aei^AR33; Tg(dlD:myc)kca⁵; lane 4, progeny of deltaD:Gal4 x UAS:myc:notch1a-intra (positive control). The size of the deltaD:myc protein is approximately 91 kDa, that of notch-intra:myc 92 kDa. The left and the right lanes show the See Blue Pre-Stained Standards marker (Novex). (C,C',C'') 14-somite stage. The pattern of expression of her1 is aberrant in aei^AR33 (C) and indistinguishable from that in aei^AR33; Tg(dlD:myc)kca⁵ (C') or in wild type (C''). (D,D',D'') Four-somite stage. The number of primary sensory neurones (islet1 in situ hybridisation) is increased in aei^AR33 (D), but normal in the transformants (D') and the wild-type embryos (D'').