VANGL1 rare variants associated with neural tube defects affect convergent extension in zebrafish.
In humans, rare non-synonymous variants in the planar cell polarity gene VANGL1 are associated with neural tube defects (NTDs). These variants were hypothesized to be pathogenic based mainly on genetic studies in a large cohort of NTD patients. In this study, we validate the potential pathogenic effect of these mutations in vivo by investigating their effect on convergent extension in zebrafish. Knocking down the expression of tri, the ortholog of Vangl2, using an antisense morpholino (MO), as shown previously, led to a defective convergent extension (CE) manifested by a shortened body axis and widened somites. Co-injection of the human VANGL1 with the tri-MO was able to partially rescue the tri-MO induced phenotype in zebrafish. In contrast, co-injection of two human VANGL1 variants, p.Val239Ile and p.Met328Thr, failed to rescue this phenotype. We next carried out overexpression studies where we measured the ability of the human VANGL1 alleles to induce a CE phenotype when injected at high doses in zebrafish embryos. While overexpressing the wild-type allele led to a severely defective CE, overexpression of either p.Val239Ile or p.Met328Thr variant failed to do so. Results from both tri-MO knockdown/rescue results and overexpression assays suggest that these two variants most likely represent "loss-of-function" alleles that affect protein function during embryonic development. Our study demonstrates a high degree of functional conservation of VANGL genes across evolution and provides a model system for studying potential variants identified in human NTDs.
Reynolds
Annie
A
Department of Obstetrics and Gynecology, CHU Sainte Justine Research Center and University of Montreal, Montreal, Quebec, Canada H3T 1C5.
McDearmid
Jonathan R
JR
Lachance
Stephanie
S
De Marco
Patrizia
P
Merello
Elisa
E
Capra
Valeria
V
Gros
Philippe
P
Drapeau
Pierre
P
Kibar
Zoha
Z
D000818:Animals; D001681:Biological Assay; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence; D004625:Embryo, Nonmammalian / Q000187:drug effects / Q000378:metabolism; D019143:Evolution, Molecular; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D050505:Mutant Proteins / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D009436:Neural Tube Defects / Q000235:genetics*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010641:Phenotype; D015027:Zebrafish / Q000196:embryology* / Q000235:genetics*; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism
D002352:Carrier Proteins; D008565:Membrane Proteins; D050505:Mutant Proteins; D016376:Oligonucleotides, Antisense; C488287:VANGL1 protein, human; C493008:VANGL1 protein, zebrafish; D029961:Zebrafish Proteins