Fig. 4. Comparison of bts1 expression with other mid-hindbrain markers. Whole-mount in situ hybridization was performed at the 75% epiboly (A-E), tail bud (G-K) and five-somite (M-Q) stages with the probes indicated (colour-coded) (dorsal views, anterior towards the top). (A,B) Single staining for bts1 and fkh3, respectively (whole-mount views of half embryos) (arrow in A indicates anterior limit of bts1; bracket in B indicates ‘diencephalic wings’ of fkh3 expression). (D) Bright-field view of a flat-mounted MHD, all other panels show a bright field view (left, red and blue labelling) and the contralateral fluorescence view (right, red labelling only) of flat-mounted neural plates. (F,L,R) Corresponding schematics of genes expression profiles (including data not shown) at 75% epiboly, tail bud and five somites, respectively. Note that anteriorly, bts1 expression never extends to the presumptive diencephalon (compare A with B), and that it crosses the caudal border of otx2 expression at all stages.
