Fig. 2. FL99 and FT59 are alleles of the gene phm.

(A) Schematic representation of the intron-exon structure of phm (adopted from Niwa et al., 2004). White rectangles correspond to 5’ and 3’ UTR, grey ones indicate translated regions. The gene phm encodes for 1991 bp cDNA product or 574 amino acids long protein. In the phm^FL99 allele parts of the first and the second exons are deleted from 359 bp until 628 bp removing amino acids 55–145. The phm^FL99 allele carries in addition a substitution of the aromatic Aspartic acid (Asp, D) at the position 146 by the hydrophobic Valine (Val, V). The phm^FT59 allele carries the same mutation as phm^E7 (Niwa et al., 2004; Warren et al., 2004), a C to T point mutation at the nucleotide position 1049, leading to a formation of an in-frame stop codon at amino acid position 286. (B) Schematic diagrams illustrating phantom proteins produced by phm^WT (adopted from Warren et al., 2004), phm^FL99 and phm^FT59 alleles. The deletion of the part of the Glycine-Proline rich domain in the phm^FL99 allele is depicted by a red asterisk. (C-E) Cuticle preparation. Wild-type cuticle (C), and lack of cuticle differentiation in phm^FT59 (D) and phm^FL99 (E) mutant embryos.