Fig. 4. Overexpression of Xror2 and its mutant constructs causes a shortened anteroposterior axis. Two blastomeres of four-cell stage embryos were injected in the ventral (/V) or dorsal (/D) equatorial region with mRNAs (1 ng/embryo) as indicated (A-G). Injected embryos were cultured until stage 38. (A,C) Globin mRNA-injected control embryos. (B) Ventral overexpression of Xror2 causes malformation in posterior structures. (D-F) Dorsal overexpression of Xror2 and kinase domain mutants (Xror2-3I, Xror2-TM) causes a shortened body axis with dorsal bending and abnormalities in head structures, including one-eyed phenotypes. (G) Xror2-KR shows much weaker phenotypes than the other constructs of Xror2.