Fig. 3

Inhibition of Hsp90 function increases the incidence of midline bifurcations. (A–D) Phenotypes of embryos injected with the Hsp90-inhibitory chemical radicicol. WT and MZsqt embryos were injected with 0.7 nl of either 27 mM radicicol in DMSO or DMSO only, and scored for the MB phenotype on 1 day post fertilization. Injection of DMSO caused no significant defects in both WT (A) and MZsqt embryos (C). Injection of radicicol in WT embryos caused slightly dark, small heads and short tails (B). Injection of radicicol in MZsqt embryos, caused these same defects, but also induced cyclopia (image not shown) and MB (D). (E) Incidence of cyclopia and MB among WT and MZsqt embryos injected with radicicol. Numbers of embryos scored are shown and correspond to a highly significant difference (p = 0.000484) in the MB rates of DMSO and radicicol treated MZsqt embryo groups. (F–I) Phenotypes of the embryos injected with an Hsp90a MO. WT and MZsqt embryos were injected with 3 ng of either control MO or an Hsp90a-targeting MO, and scored for the MB phenotype on 1 day post fertilization. The control MO caused no obvious defects in WT (F) or MZsqt embryos (H). Injection of Hsp90a MO into WT embryos generated severe defects, including dark heads and very short tails, but no MB phenotype was seen (G). Injection of the Hsp90a MO into MZsqt embryos, caused these same defects, but also induced cyclopia (image not shown) and MB (I). (J) Incidence of cyclopia and MB among WT and MZsqt embryos injected with the Hsp90a MO. Numbers of embryos scored are shown and correspond to a highly significant difference (p = 0.000001) in the MB rates of control and HSP90a MO-injected MZsqt embryos. Percentages for each phenotype are indicated: normal appearing (white); cyclopia alone (green); MB alone (red) and MB + cyclopia (yellow).