TY - JOUR
T1 - Fgf signaling negatively regulates Nodal-dependent endoderm induction in zebrafish
AU - Mizoguchi, Takamasa
AU - Izawa, Toshiaki
AU - Kuroiwa, Atsushi
AU - Kikuchi, Yutaka
N1 - Funding Information:
We thank Tokuko Niwa, Hiroko Nishii and Mika Yamada for both fish maintenance and technical assistance. We also thank Igor Dawid, Hiroshi Hanafusa, Thierry Lepage, Bernard Thisse, Akihito Yamamoto and Joseph Yost for providing useful DNA templates. We are grateful to Atsuo Kawahara and Hitoshi Okamoto for technical advice, Thierry Lepage for sharing his unpublished data and Heather Verkade for careful reading of the manuscript. This work was supported by grants from the Mitsubishi Foundation, Takeda Foundation and Grant-in-Aid for Scientific Research from The Ministry of Education, Science, Sports and Technology (KAKENHI 13138204 and 16027223) and by the Japan Society for the Promotion of Science (KAKENHI 15370094) to Y.K.
PY - 2006/12/15
Y1 - 2006/12/15
N2 - In zebrafish development, Nodal signaling is critical for the induction of endoderm and mesoderm. Three transcription factors downstream of Nodal, Bonnie and Clyde (Bon), Faust (Fau)/Gata5 and Casanova (Cas), are required for endoderm induction. However, it is not yet fully understood how the Nodal signaling pathway regulates the decision process of endoderm and mesoderm induction. In this study, we focused on Fgf signaling, downstream of Nodal signaling, during endoderm induction. We found that activation of Fgf signaling decreases the number of cas-expressing endodermal cells. Conversely, inhibition of this signaling increases the number of endodermal cells without affecting the expression of Nodal, Nodal antagonists, bon or fau/gata5. Inhibition of Fgf signaling in endoderm mutants suggests that this signaling negatively regulates cas expression by a pathway parallel to Bon and Fau/Gata5 in the molecular cascade leading to endoderm. Furthermore, activation of Fgf signaling can overcome Cas-mediated abrogation of mesodermal gene expression. Altogether, these results suggest that Fgf signaling negatively regulates endoderm induction, possibly through repression of cas expression and down-regulation of Cas function.
AB - In zebrafish development, Nodal signaling is critical for the induction of endoderm and mesoderm. Three transcription factors downstream of Nodal, Bonnie and Clyde (Bon), Faust (Fau)/Gata5 and Casanova (Cas), are required for endoderm induction. However, it is not yet fully understood how the Nodal signaling pathway regulates the decision process of endoderm and mesoderm induction. In this study, we focused on Fgf signaling, downstream of Nodal signaling, during endoderm induction. We found that activation of Fgf signaling decreases the number of cas-expressing endodermal cells. Conversely, inhibition of this signaling increases the number of endodermal cells without affecting the expression of Nodal, Nodal antagonists, bon or fau/gata5. Inhibition of Fgf signaling in endoderm mutants suggests that this signaling negatively regulates cas expression by a pathway parallel to Bon and Fau/Gata5 in the molecular cascade leading to endoderm. Furthermore, activation of Fgf signaling can overcome Cas-mediated abrogation of mesodermal gene expression. Altogether, these results suggest that Fgf signaling negatively regulates endoderm induction, possibly through repression of cas expression and down-regulation of Cas function.
KW - Endoderm
KW - Fgf
KW - Induction
KW - Zebrafish
KW - bonnie and clyde
KW - casanova
KW - faust/gata5
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U2 - 10.1016/j.ydbio.2006.08.073
DO - 10.1016/j.ydbio.2006.08.073
M3 - Article
C2 - 17026981
AN - SCOPUS:33845453906
VL - 300
SP - 612
EP - 622
JO - Developmental Biology
JF - Developmental Biology
SN - 0012-1606
IS - 2
ER -