Regulatory gene expression boundaries demarcate sites of neuronal differentiation in the embryonic zebrafish forebrain.
During development of the zebrafish forebrain, a simple scaffold of axon pathways is pioneered by a small number of neurons. We show that boundaries of expression domains of members of the eph, forkhead, pax, and wnt gene families correlate with the positions at which these neurons differentiate and extend axons. Analysis of genetically or experimentally altered forebrains indicates that if a boundary is maintained, there is appropriate neural differentiation with respect to the boundary. Conversely, in the absence of a boundary, there is concomitant disruption of neural patterning. We also show that a strip of cells within the dorsal diencephalon shares features with ventral midline cells. This strip of cells fails to develop in mutant fish in which specification of the ventral CNS is disrupted, suggesting that its development may be regulated by the same inductive pathways that pattern the ventral midline.
Macdonald
R
R
Developmental Biology Research Centre, Randall Institute, Kings College London, England.
Xu
Q
Q
Barth
K A
KA
Mikkola
I
I
Holder
N
N
Fjose
A
A
Krauss
S
S
Wilson
S W
SW
D000818:Animals; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000235:genetics; D005136:Eye Proteins; D051858:Forkhead Transcription Factors; D018507:Gene Expression Regulation, Developmental; D005809:Genes, Regulator; D018398:Homeodomain Proteins; D017403:In Situ Hybridization; D009024:Morphogenesis; D009434:Neural Pathways / Q000196:embryology; D009474:Neurons / Q000166:cytology*; D051762:PAX2 Transcription Factor; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D016548:Prosencephalon / Q000196:embryology*; D011518:Proto-Oncogene Proteins / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D012097:Repressor Proteins; D014157:Transcription Factors / Q000235:genetics; D051153:Wnt Proteins; D015027:Zebrafish; D029961:Zebrafish Proteins
D004268:DNA-Binding Proteins; D005136:Eye Proteins; D051858:Forkhead Transcription Factors; D018398:Homeodomain Proteins; D051762:PAX2 Transcription Factor; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D011518:Proto-Oncogene Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D051153:Wnt Proteins; D029961:Zebrafish Proteins; C082243:foxa2 protein, zebrafish; C497320:pax2a protein, zebrafish; C094522:wnt8b protein, zebrafish; D020794:Receptor Protein-Tyrosine Kinases