Fig. 8. Fgf8 is not detected in the dermomyotome of Splotch embryos. Whole-mount in situ hybridization showing the expression pattern of Fgf8 in control and Splotch embryos. Fgf8, which is normally expressed in the dermomyotome, is not detectable in the somite of Splotch and high chimeric (>80% of Pax3^-/- cells) embryos at all stages analyzed (E9.0-E10.5). The expression in the hindbrain and limb bud is not affected in Splotch embryos. (A) Control embryo (E9.5); (B) Splotch^2H embryo (E9.0); (C) Sagittal section of embryo in A showing the expression of Fgf8 in the caudal and rostral lips of the dermomyotome as indicated by black arrowheads, rostral is to the left; (D) chimeric embryo (generated with Pax3^-/- ES cells) stained for ß-galactosidase and hybridized with Fgf8 probe; hybridization in the limb bud is indicated by arrows; in the somites only the X-gal staining is detectable. DM, dermomyotome. Scale bars: 500 µm in A,B,D; 100 µm in C.