Figure 1
Schematic illustration, cuticular phenotype and developmental progression of Raf926 mutant embryo. (A) Domain organization of Drosophila Raf, Raf926 and RafGOF. Raf protein contains the Ras-binding domain (RBD) in conserved region 1 (CR1), negative regulatory domain (NRD) in CR2 and protein kinase domain in CR3, with a total length of 739 amino acids. Raf926 comprised of an altered RBD with 207 amino acids in total due to a deletion of 17 nucleotides which resulted in a frameshift and premature stop codon. RafGOF contains the kinase domain only, with total length of 309 amino acids. Dark field micrographs of the cuticles of wild type embryo showing normal distribution of ventral denticles and dorsal hair (B), a cactus1 mutant embryo showing strongly ventralized phenotype with ventral denticles expression among the dorsal hair (C) and Raf926 mutant embryo showing a strongly dorsalized phenotype with elongated, tube-like, twisted body entirely covered by dorsal hair (D). (E–H) Still images of developmental stages of a wild-type embryo to be compared to still images of developmental stages of Raf926 embryo from lightsheet (E′–H′) and scanning electron microscope (SEM) (E″–H″). Raf926 embryos develop normally up to cellularization stage. Defective gastrulation is characterized by frequent twisting, elongation of twisted segments, fusions of segments into three main sacs, followed by tissue death. Embryo was visualised with Utrophin-GFP and Histone-RFP, with anterior to the left. Stills were extracted from Video 3.
