Fig. 3. XMeis3 induces hindbrain and neurogenic, but not mesodermal, marker expression. (A) In situ hybridization to the r5/r6 HoxB3 gene. HoxB3 is expressed in >70% of the elongating BMPDNR-expressing explants (n=17/24). XMeis3-expressing AC explants recombined with a control AC explants did not express HoxB3 (not shown; n=0/13). (B) In situ hybridization to the neurogenic n-tubulin gene, which is expressed in >50% of the elongating BMP-DNR-expressing explants (n=18/34). XMeis3-expressing explants recombined with neither a control AC explant nor an uninjected control AC explant recombined with a BMP-DNR-expressing explant expressed n-tubulin (n=0/53; not shown). (C) Immunohistochemistry to the notochord-specific Tor70 marker. The elongated DMZ explants stains strongly (n=8/8) in comparison to (D) the elongated XMeis3/BMP DNR explants (n=0/18). Some non-specific background is seen in the unbleached pigmented animal cap cells.