PUBLICATION

Isthmin1, a secreted signaling protein, acts downstream of diverse embryonic patterning centers in development

Authors
Kesavan, G., Raible, F., Gupta, M., Machate, A., Yilmaz, D., Brand, M.
ID
ZDB-PUB-201229-42
Date
2020
Source
Cell and tissue research   383(3): 987-1002 (Journal)
Registered Authors
Brand, Michael, Gupta, Mansi, Kesavan, Gokul, Machate, Anja, Raible, Florian
Keywords
FCS, Fgf signaling, Isthmin1, Isthmin2, Nodal signaling, Secreted factors, Zebrafish
MeSH Terms
  • Animals
  • Animals, Genetically Modified/embryology*
  • Body Patterning
  • Gene Expression Regulation, Developmental
  • Zebrafish/embryology*
  • Zebrafish Proteins/physiology*
PubMed
33367974 Full text @ Cell Tissue Res.
Abstract
Extracellular signals play essential roles during embryonic patterning by providing positional information in a concentration-dependent manner, and many such signals, like Wnt, fibroblast growth factor (FGF), Hedgehog (Hh), and retinoic acid, act by being secreted into the extracellular space, thereby triggering receptor-mediated responses in other cells. Isthmin1 (ism1) is a secreted protein whose gene expression pattern coincides with that of early dorsal determinants, nodal ligand genes like sqt and cyc, and with fgf8 during various phases of zebrafish development. Ism1 functions in early embryonic patterning and development are poorly understood; however, it has recently been shown to interact with nodal pathway genes to control organ asymmetry in chicken. Here, we show that misexpression of ism1 deletion constructs disrupts embryonic patterning in zebrafish and exhibits genetic interactions with both Fgf and nodal signaling. Unlike Fgf and nodal pathway mutants, CRISPR/Cas9-engineered ism1 mutants did not show obvious developmental defects. Further, in vivo single molecule fluorescence correlation spectroscopy (FCCS) showed that Ism1 diffuses freely in the extra-cellular space, with a diffusion coefficient similar to that of Fgf8a; however, our measurements do not support direct molecular interactions between Ism1 and either nodal ligands or Fgf8a in the developing zebrafish embryo. Together, data from gain- and loss-of-function experiments suggest that zebrafish Ism1 plays a complex role in regulating extracellular signals during early embryonic development.
Genes / Markers
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Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping