Essential role of Bmp signaling and its positive feedback loop in the early cell fate evolution of chordates

0423225 - ÚMG 2014 RIV US eng J - Journal Article
Kozmiková, Iryna - Candiani, S. - Fabian, Peter - Gurská, Daniela - Kozmik, Zbyněk
Essential role of Bmp signaling and its positive feedback loop in the early cell fate evolution of chordates.
Developmental Biology. Roč. 382, č. 2 (2013), s. 538-554. ISSN 0012-1606. E-ISSN 1095-564X
R&D Projects: GA ČR GCP305/10/J064; GA MŠMT EE2.3.30.0027
Institutional support: RVO:68378050
Keywords : Bmp signaling * axial patterning * cell fate * chordates * evolution
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 3.637, year: 2013

In chordates, early separation of cell fate domains occurs prior to the final specification of ectoderm to neural and non-neural as well as mesoderm to dorsal and ventral during development. Maintaining such division with the establishment of an exact border between the domains is required for the formation of highly differentiated structures such as neural tube and notochord. We hypothesized that the key condition for efficient cell fate separation in a chordate embryo is the presence of a positive feedback loop for Bmp signaling within the gene regulatory network (GRN), underlying early axial patterning. Here, we therefore investigated the role of Bmp signaling in axial cell fate determination in amphioxus, the basal chordate possessing a centralized nervous system. Pharmacological inhibition of Bmp signaling induces dorsalization of amphioxus embryos and expansion of neural plate markers, which is consistent with an ancestral role of Bmp signaling in chordate axial patterning and neural plate formation. Furthermore, we provided evidence for the presence of the positive feedback loop within the Bmp signaling network of amphioxus. Using mRNA microinjections we found that, in contrast to vertebrate Vent genes, which promote the expression of Bmp4, amphioxus Vent1 is likely not responsible for activation of cephalochordate ortholog Bmp2/4. Cis-regulatory analysis of amphioxus Bmp2/4, Admp and Chordin promoters in medaka embryos revealed remarkable conservation of the gene regulatory information between vertebrates and basal chordates. Our data suggest that emergence of a positive feedback loop within the Bmp signaling network may represent a key molecular event in the evolutionary history of the chordate cell fate determination.
Permanent Link: http://hdl.handle.net/11104/0229371