PUBLICATION

Functional testing of a human PBX3 variant in zebrafish reveals a potential modifier role in congenital heart defects.

Authors
Farr, G.H., Imani, K., Pouv, D., Maves, L.
ID
ZDB-PUB-181026-13
Date
2018
Source
Disease models & mechanisms   11(10): (Journal)
Registered Authors
Farr III, G. Hank, Maves, Lisa
Keywords
CRISPR-Cas9, Genetic variant, Heart, Modifier, Pbx, Zebrafish
MeSH Terms
  • Genetic Association Studies
  • Myocardium/pathology
  • Mutation/genetics*
  • Morphogenesis
  • Heart Defects, Congenital/genetics*
  • Humans
  • Homeodomain Proteins/genetics*
  • Zebrafish/genetics*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
  • Proto-Oncogene Proteins/genetics*
  • Mutagenesis/genetics
  • Base Sequence
  • Animals
  • Genetic Engineering
(all 15)
PubMed
30355621 Full text @ Dis. Model. Mech.
Abstract
Whole-genome and exome sequencing efforts are increasingly identifying candidate genetic variants associated with human disease. However, predicting and testing the pathogenicity of a genetic variant remains challenging. Genome editing allows for the rigorous functional testing of human genetic variants in animal models. Congenital heart defects (CHDs) are a prominent example of a human disorder with complex genetics. An inherited sequence variant in the human PBX3 gene (PBX3 p.A136V) has previously been shown to be enriched in a CHD patient cohort, indicating that the PBX3 p.A136V variant could be a modifier allele for CHDs. Pbx genes encode three-amino-acid loop extension (TALE)-class homeodomain-containing DNA-binding proteins with diverse roles in development and disease, and are required for heart development in mouse and zebrafish. Here, we used CRISPR-Cas9 genome editing to directly test whether this Pbx gene variant acts as a genetic modifier in zebrafish heart development. We used a single-stranded oligodeoxynucleotide to precisely introduce the human PBX3 p.A136V variant in the homologous zebrafish pbx4 gene (pbx4 p.A131V). We observed that zebrafish that are homozygous for pbx4 p.A131V are viable as adults. However, the pbx4 p.A131V variant enhances the embryonic cardiac morphogenesis phenotype caused by loss of the known cardiac specification factor, Hand2. Our study is the first example of using precision genome editing in zebrafish to demonstrate a function for a human disease-associated single nucleotide variant of unknown significance. Our work underscores the importance of testing the roles of inherited variants, not just de novo variants, as genetic modifiers of CHDs. Our study provides a novel approach toward advancing our understanding of the complex genetics of CHDs.
Genes / Markers
Figures
Figure Gallery (2 images)
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Expression
Phenotype
Mutations / Transgenics
Allele Construct Type Affected Genomic Region
b557
    Point Mutation
    s6
      Deficiency
      scm8
        Indel
        scm14
          Point Mutation
          1 - 4 of 4
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          Human Disease / Model
          No data available
          Sequence Targeting Reagents
          1 - 5 of 5
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          Fish
          Antibodies
          Name Type Antigen Genes Isotypes Host Organism
          Ab1-pbxpolyclonalRabbit
          1 - 1 of 1
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          Orthology
          No data available
          Engineered Foreign Genes
          No data available
          Mapping
          No data available