Abstract
Wnts have been shown to provide a posteriorizing signal that has to be repressed in the anterior neuroectoderm for normal anteroposterior (AP) patterning. We have previously identified a zebrafish frizzled8a (fz8a) gene expressed in the presumptive anterior neuroectoderm as well as prechordal plate at the late gastrula stage. We have investigated the role of Fz8a-mediated Wnt8b signalling in anterior brain patterning in zebrafish. We show that in zebrafish embryos: (1) Wnt signalling has at least two different stage-specific posteriorizing activities in the anterior neuroectoderm, one before mid-gastrulation and the other at late gastrulation; (2) Fz8a plays an important role in mediating anterior brain patterning; (3) Wnt8b and Fz8a can functionally interact to transmit posteriorizing signals that determine the fate of the posterior diencephalon and midbrain in late gastrula embryos; and (4) Wnt8b can suppress fz8a expression in the anterior neuroectoderm and potentially affect the level and/or range of Wnt signalling. In conclusion, we suggest that a gradient of Fz8a-mediated Wnt8b signalling may play crucial role in patterning the posterior diencephalon and midbrain regions in the late gastrula.
Original language | English |
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Pages (from-to) | 4443-4455 |
Number of pages | 13 |
Journal | Development |
Volume | 129 |
Issue number | 19 |
Publication status | Published - 2002 Oct |
Externally published | Yes |
Keywords
- Anterior neuroectoderm
- Brain patterning
- Diencephalon
- Eye primordia
- Fz8a
- Midbrain
- Wnt8b
- Zebrafish
ASJC Scopus subject areas
- Molecular Biology
- Developmental Biology