FIGURE 2.

Efr was involved in HS-GAG biosynthesis in vivo. A, genomic organization of the Efr locus. The exons of the Efr gene are shown as boxes, and the predicted coding regions are filled in black. The genomic regions deleted in the Efr¹, Efr², and Efr³ mutants are indicated by parentheses. In the Efr¹ mutant, a ∼1.2-kb genomic region that includes a predicted initiation codon, was deleted. In the Efr² mutant, a ∼1.5-kb genomic region that includes the first and second exons was deleted. In the Efr³ mutant, a ∼0.5-kb genomic region that includes the first exon was deleted. BG02156 was the original P-element insertion line, and a triangle indicates the position of the P-element insertion site. B–E, adult wings. B, a wild-type wing. C and D, a wing of Efr³/Efr³ (C) and a wing of Efr³/Efr³ (D), demonstrating the gap in the fifth longitudinal vein (arrow). In D, a gap in the posterior cross-vein was also observed (arrowhead). E, a wing of Efr³/Efr¹ carrying a transgene of the Efr genome fragment. The wing vein gap was completely rescued. F–H, anti-heparan sulfate (3G10) staining of the late third instar wing discs. F, a wild-type wing disc. G and H, a chimeric wing disc, including Efr²/Efr² cells, which are marked by the absence of GFP (H). Note that the intensity of anti-heparan sulfate staining was reduced in the mutant cells (G). I–K, late third instar wing discs stained with an anti-p-Mad antibody (magenta). I, a wild-type wing disc. J and K, a chimeric wing disc, including Efr¹/Efr¹ cells, which are marked by the absence of GFP (green in J). Anti-p-Mad antibody staining was decreased in Efr¹ mutant cells (regions indicated by brackets in I compared with that of K). Bar, 25 μm.