Figure 5. Tight junction integrity is disrupted by expression of either DNPar6 or Vangl2MO.

Using a biotin permeability assay, embryos were examined for tight junction integrity. A) Tight junctions were maintained in control embryos, determined because very little biotin was able to penetrate into the embryos. Arrows indicate areas where biotin signal penetrates the embryo; this signal was never observed more than 1 cell depth. B) In embryos injected with DNPar6 or C) Vangl2MO, the biotin signal was observed several cell layers deep in the embryo (arrowheads), indicating that tight junction integrity was affected. Similar results were obtained with embryos cultured in Mg²⁺/Ca²⁺-free medium, which is known to break tight junctions (data not shown). This could be interpreted as showing that tight junctions never formed properly in these embryos, or alternatively that tight junctions were disrupted. Numbers on panels indicate the number of embryos observed with the phenotype over the total number of embryos examined.