PUBLICATION

Accurate quantification of homologous recombination in zebrafish: brca2 deficiency as a paradigm

Authors
Vierstraete, J., Willaert, A., Vermassen, P., Coucke, P.J., Vral, A., Claes, K.B.M.
ID
ZDB-PUB-171204-20
Date
2017
Source
Scientific Reports   7: 16518 (Journal)
Registered Authors
Coucke, Paul, Willaert, Andy
Keywords
none
MeSH Terms
  • Animals
  • Animals, Genetically Modified
  • BRCA2 Protein/deficiency*
  • Embryo, Nonmammalian
  • Gene Knockdown Techniques
  • Genetic Testing*
  • Genotyping Techniques
  • Homologous Recombination*/radiation effects
  • Immunohistochemistry
  • Rad51 Recombinase/metabolism
  • Radiation, Ionizing
  • Zebrafish/genetics*
  • Zebrafish Proteins/deficiency*
PubMed
29184099 Full text @ Sci. Rep.
Abstract
Homologous Recombination (HR) repair is essential for repairing DNA double strand breaks (DSB) in dividing cells and preventing tumorigenesis. BRCA2 plays an important role in HR by recruiting the DNA recombinase RAD51 to the DSB. Despite being a popular model organism in genetic and cancer research, knowledge on the conservation of the HR pathway and function of zebrafish Brca2 is limited. To evaluate this, we developed a Rad51 foci assay in zebrafish embryos. We identified the zebrafish embryonic intestinal tissue as an ideal target for Rad51 immunostaining. After inducing DSB through irradiation, Rad51 foci were present in irradiated embryos but not in unirradiated controls. We present a method for accurate quantification of HR. Both morpholino-induced knockdown and knockout of Brca2 lead to almost complete absence of Rad51 foci in irradiated embryos. These findings indicate conserved function of Brca2 in zebrafish. Interestingly, a statistically significant decrease in Rad51 foci was observed in Brca2 heterozygous carriers compared to wild types, indicative of haploinsufficiency, a hypothesised cause of some tumours in patients with a germline BRCA2 mutation. In conclusion, we demonstrated the suitability of zebrafish as an excellent in vivo model system for studying the HR pathway and its functionality.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping