Midline signals regulate retinal neurogenesis in zebrafish.
In zebrafish, neuronal differentiation progresses across the retina in a pattern that is reminiscent of the neurogenic wave that sweeps across the developing eye in Drosophila. We show that expression of a zebrafish homolog of Drosophila atonal, ath5, sweeps across the eye predicting the wave of neuronal differentiation. By analyzing the regulation of ath5 expression, we have elucidated the mechanisms that regulate initiation and spread of neurogenesis in the retina. ath5 expression is lost in Nodal pathway mutant embryos lacking axial tissues that include the prechordal plate. A likely role for axial tissue is to induce optic stalk cells that subsequently regulate ath5 expression. Our results suggest that a series of inductive events, initiated from the prechordal plate and progressing from the optic stalks, regulates the spread of neuronal differentiation across the zebrafish retina.
Masai
I
I
Laboratory for Developmental Gene Regulation, Brain Science Institute, RIKEN, Saitama, Japan. imasai@brain.riken.go.jp
Stemple
D L
DL
Okamoto
H
H
Wilson
S W
SW
D000818:Animals; D002454:Cell Differentiation / Q000235:genetics; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D004627:Embryonic Induction / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000235:genetics; D006133:Growth Substances; D066298:In Vitro Techniques; D009154:Mutation; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D055457:Nodal Protein; D009928:Organ Specificity / Q000235:genetics; D051762:PAX2 Transcription Factor; D012160:Retina / Q000166:cytology / Q000196:embryology* / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*; D014157:Transcription Factors / Q000096:biosynthesis; D016212:Transforming Growth Factor beta / Q000378:metabolism / Q000494:pharmacology; D014795:Visual Pathways / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D015027:Zebrafish / Q000196:embryology*; D029961:Zebrafish Proteins
D004268:DNA-Binding Proteins; D006133:Growth Substances; D055457:Nodal Protein; D051762:PAX2 Transcription Factor; D014157:Transcription Factors; D016212:Transforming Growth Factor beta; D029961:Zebrafish Proteins; C413414:atoh7 protein, zebrafish; C497320:pax2a protein, zebrafish