Expression of the neurotrophic factor neurotrophin 3 in visually impaired mutants.
(A) Relative expression levels of bdnf, ntf3, ntf4, ntf7, and ngf in 4 dpf old wild-type and kif5aa mutant embryos. ntf3 is upregulated to 160% of wild-type expression levels (p < 0.05) while all other neurotrophic factors show the same expression levels between wild-type and mutant embryos. (B) Transversal sections through the tectum after in situ hybridization with an ntf3 specific antisense probe detect higher expression levels of ntf3 in tecta of kif5aa. Scale bars = 25 µm. PC = pigment cell, NP = neuropil, PVN = periventricular neurons. Asterisk = strong ntf3 signal in the otic vesicle. (C) Confirmation of Ntf3 overexpression by Western blotting in 4 dpf old embryos. To show the specificity of the antibody, we generated a Ntf3 overexpression construct (UAS:ntf3-E2A-RFP). The two visually impaired mutant lines lakritz and blumenkohl also show a substantial upregulation of ntf3 expression levels. (D) Quantification of Ntf3 protein expression levels based on Western blotting data in wild-type and visually impaired mutant embryos. All three mutant lines show a substantial upregulation of Ntf3 protein levels.