Fig. 6

A-H: Heat shock-induced Emx3 protein partially rescues emx3 morpholino antisense oligonucleotides (MO) -induced knockdown, whereas excessive Emx3 dorsalizes the telencephalon. A-C,E-G: Low levels of Emx3-myc-GFP expression (e3-GFP⁺), induced by heat shock at the 1- or 2-somite stages (10.5 hr, hs2s), 20-30 min after the onset of endogenous emx3 mRNA expression at bud stage, rescues the emx3MO-induced down regulation of tcf4l (A-C) and eomesa (eom., E-G). Later heat shock, between the 5- and 7-somite stages (11.5 hr, hs5s), does not rescue the phenotype (B,D). Higher levels of GFP expression after heat shock (e3-GFP⁺⁺), indicating higher levels of Emx3 activity, lead to dorsalized telencephalon as assessed by ventrally expanded expression of tcf4l (A,H). A-D,H: Frontal views, dorsal to the top, 25 hr; (E-G) Dorsal view, rostral to the left, 12-somite stage (15 hr). Scale bar = 100 μm.