1. Pax2a and Pax8 are required for induction of otic cell fates.
Pax2a and Pax8 are required for induction of otic cell fates. (A) Schematic map of protein domain structure of Pax2a and the dominant-negative variant, dnPax2a-myc. In dnPax2a-myc, the 295 N-terminal amino acids are fused in frame with six Myc-epitopes. The numbers indicate amino acids of the domains (Lun and Brand, 1998). (B,C) dnPax2a-myc acts in a dominant-negative fashion. At the three-somite stage, eng3 (blue) is expressed in the isthmic region (B), whereas in wild-type embryos injected with dnpax2a-myc, the side expressing the transgene shows reduced or no eng3 (blue) expression (C). The distribution of the Myc-epitope (brown) indicates the localization of the Pax2a variant in nuclei. Expression of dominant-negative Pax2a leads to downregulation of sox9a (D,D′,D″), sox9b (E,E′,E″) and pax2a (F,F′,F″) but has only slight effects on dlx3b (G-G′). (D-G) Fluorescence images ofα -Myc antibody labeling; (D′-G′) fluorescence images of mRNA in situ hybridization probes; (D″-G″) merged fluorescence images. (B-G″) Dorsal views, anterior towards the top. Scale bar: 120 μm.
Stefan Hans et al. Development 2004;131:
© 2004.