Fig. 8

Increased GluA2α^Q is sufficient to induce the neural crest defects observed in the adar2MOt.

Lateral views of 18-somite stage embryos. (A) Expressions of crestin and sox9b in the hypo-Q/R-editing morphants are affected. Morphants created in the wild type and p53 mutant show negligible differences, indicating that the expression defects in the hypo-Q/R-editing morphants are p53-independent. (B) Overexpression of GluA2α^R partially restores the expressions of crestin and sox9b in the adar2MOt. Injection of gria2α^R cRNA into the wild type zygotes does not alter the expressions of crestin and sox9b (b1 and b5). However, injection of gria2α^R cRNA into the adar2MOt fully or partially rescues the expressions. Effects of rescue range from weak (b2 and b6), medium (b3 and b7) to full (b4 and b8). Weak rescue of crestin expression is defined by slightly enhanced expression in the first (1) and second (2) streams of migration neural crest cells (b2), medium rescue is defined by enhanced anterior expression (b3), and full rescue is defined by restoring the wild type expression pattern and level. Rescue of sox9b expression is classified by the enhancement of overall sox9b expression (b6-b8). Rescue efficiencies are indicated. (C) Overexpression of GluA2α^Q affects the expressions of crestin and sox9b. The crestin and sox9b expressions in gria2α^Q cRNA-injected embryos (c1 and c5) are affected as that of adar2MOt. The crestin and sox9b expressions are further reduced in adar2MOt by overexpressing GluA2α^Q. The additive effect varies from strong (c2 and c6), medium (c3 and c7), to weak (c4 and c8) further reduction of crestin and sox9b expressions. The occurrence rate of each phenotype is shown. 1, 2, 3, the first, second and third steams of migration cranial neural crest; e, eye; ep, epiphysis; f, forebrain; hb, hindbrain; VaNC, vagal neural crest.