Fig. 1. Sox9 deletion in the oligodendrocyte lineage. (A) Schematic representation of Sox9 and Sox10 alleles and the Sox10::Cre transgene used in this study. Boxes represent exons with translated parts being filled or expression cassettes for neomycin resistance (neo), β-galactosidase (lacZ) and Cre recombinase (Cre). Ellipses indicate positions of loxP sites, arrowheads those of genotyping primers a-i. (B-M) Sox9 immunoreactivity (red) was detected at 12.5 dpc (B-G) and 15.5 dpc (H-M) alone (B,E,H,K) or together with Olig2 (C,F,I,L) or Sox10 (D,G,J,M) immunoreactivity (green) in transverse spinal cord sections from the forelimb region of wild-type (B,C,D,H,I,J) or Sox9^loxP/loxP, Sox10::Cre (Sox9^/) (E,F,G,K,L,M) embryos. The region from which I,J,L,M were taken is boxed in H and K.