ZFIN ID: ZDB-PUB-091023-7
A gap junction connexin is required in the vertebrate left-right organizer
Hatler, J.M., Essner, J.J., and Johnson, R.G.
Date: 2009
Source: Developmental Biology   336(2): 183-191 (Journal)
Registered Authors: Essner, Jeffrey
Keywords: Connexin, Kupffer's vesicle, Left–right asymmetry, Morphogenesis
MeSH Terms:
  • Animals
  • Body Patterning*
  • Connexin 43/genetics
  • Connexin 43/physiology*
  • Gene Expression Regulation, Developmental
  • Mosaicism
  • Zebrafish
PubMed: 19799895 Full text @ Dev. Biol.
Early patterning of vertebrate embryos involves the generation of asymmetric signals across the left-right (L-R) axis that position and are required for the proper function of internal organs. This patterning is directed by a conserved nodal/lefty signaling cascade on the left side of the embryo, thought to be asymmetrically directed by ciliary beating that generates a leftward fluid flow in the mammalian node and in Kupffer's vesicle (KV), the related structure in zebrafish. Following morpholino knockdown of Cx43.4, asymmetric gene expression and global organ distribution are randomized, consistent with the expression of Cx43.4 in KV. Randomization is recapitulated in mosaic embryos in which Cx43.4 is depleted preferentially in KV cells, showing that Cx43.4 is specifically required in KV for proper L-R axis formation. The mechanistic basis for the laterality anomalies in Cx43.4-deficient embryos is a primary morphogenesis defect during lumen formation in KV. Additionally, the role of Cx43.4 appears to be conserved given that its ortholog, human Cx45, is able to functionally compensate for zebrafish Cx43.4 during L-R patterning. This is the first report linking connexin function in the ciliated, node-like cells of KV with normal L-R axis development.