Fig. 10.
Regulation of gli1 expression requires Gli3, but not Gli1 or Gli2, function. All panels show lateral views of the hindbrain with anterior to the left. Embryos in A–E were obtained from crosses between dtrte370+/− heterozygotes, while those in F–P were obtained from crosses between yotty119+/− heterozygotes. Krox20 expression (red) in ptc1;krox20 double in situ panels identifies rhombomeres 3 and 5. (A) In 21 hpf uninjected or gli2 MO-injected wild-type embryos, ptc1 is expressed at all axial levels in the ventral hindbrain. (B) In an uninjected dtr mutant, ptc1 expression is significantly reduced. (C) In a gli2 MO-injected dtr mutant, ptc1 expression is completely lost in the hindbrain. (D) In a 21-hpf uninjected or gli2 MO-injected wild-type embryo, gli1 is expressed at all axial levels in the ventral half/two-thirds of the hindbrain. (E) Gli1 expression is unaffected in control or gli2 MO-injected dtr mutants. (F–H) Ptc1 expression is normal in uninjected or gli1 MO-injected wild-type embryos (F), is reduced significantly in an uninjected yot mutant (G), and is completely lost from the hindbrain in a gli1 MO-injected yot mutant (H). (I and J) Gli1 is expressed normally in the ventral hindbrain in uninjected or gli1 MO-injected wild-type (I) or yot mutants (J). (K–M) Ptc1 expression is slightly reduced in a gli3 MO-injected 22 hpf wild-type embryo (K), is reduced significantly in an uninjected 24 hpf yot mutant (L), and is almost completely lost in a gli3 MO-injected 22 hpf yot mutant (M). (N–P) Gli1 is expressed normally in the ventral hindbrain in uninjected wild-type or yot mutant embryos (N), and in a gli3 MO-injected wild-type embryo (O). In a gli3 MO-injected yot mutant, gli1 expression is greatly reduced (P).