Fig. 6.

Injection of dominant-negative GlyR α1 subunit R270Q mutant RNA recapitulates glra1 morphant spasticity. A, B. Populations of 30 hpf larvae were injected as zygotes with ~ 2 ng of either wild type, A, or R270Q dominant-negative glra1 RNA, B. While R270Q glra1 RNA-injected larvae were morphologically normal, surprisingly, 60% of wild type glra1 RNA-injected larvae exhibited shortened axis and cyclopic phenotypes. These phenotypes are more commonly associated with defects in early signaling through the sonic hedgehog pathway and are likely a consequence of expressing functional glycine receptors at a time when they are not normally expressed. In A, boxed inset, it is possible to see the medially fused eyes characteristic of the Cyclops phenotype. C. Percentages of larvae from different treatment groups that exhibited spastic or Cyclops phenotypes or mortality are plotted. RNAs encoding wild type and GlyR α1 subunit R270Q mutant were each injected at two concentrations indicated by the wedge (wt high ~ 2 ng, n = 25; low ~ 400 pg, n = 23; R270Q high ~ 2 ng, n = 42; low ~ 400 pg, n = 17).