PUBLICATION

Zebrafish nampt-a mutants are viable despite perturbed primitive hematopoiesis

Authors
Pomreinke, A.P., Müller, P.
ID
ZDB-PUB-240430-8
Date
2024
Source
Hereditas   161: 1414 (Journal)
Registered Authors
Müller, Patrick
Keywords
none
MeSH Terms
  • Animals
  • CRISPR-Cas Systems
  • Gene Knockdown Techniques
  • Hematopoiesis*/genetics
  • Morpholinos/genetics
  • Mutation
  • NAD/metabolism
  • Nicotinamide Phosphoribosyltransferase*/genetics
  • Phenotype
  • Zebrafish*/genetics
  • Zebrafish Proteins/genetics
PubMed
38685093 Full text @ Hereditas
Abstract
Nicotinamide phosphoribosyltransferase (Nampt) is required for recycling NAD+ in numerous cellular contexts. Morpholino-based knockdown of zebrafish nampt-a has been shown to cause abnormal development and defective hematopoiesis concomitant with decreased NAD+ levels. However, surprisingly, nampt-a mutant zebrafish were recently found to be viable, suggesting a discrepancy between the phenotypes in knockdown and knockout conditions. Here, we address this discrepancy by directly comparing loss-of-function approaches that result in identical defective transcripts in morphants and mutants.
Using CRISPR/Cas9-mediated mutagenesis, we generated nampt-a mutant lines that carry the same mis-spliced mRNA as nampt-a morphants. Despite reduced NAD+ levels and perturbed expression of specific blood markers, nampt-a mutants did not display obvious developmental defects and were found to be viable. In contrast, injection of nampt-a morpholinos into wild-type or mutant nampt-a embryos caused aberrant phenotypes. Moreover, nampt-a morpholinos caused additional reduction of blood-related markers in nampt-a mutants, suggesting that the defects observed in nampt-a morphants can be partially attributed to off-target effects of the morpholinos.
Our findings show that zebrafish nampt-a mutants are viable despite reduced NAD+ levels and a perturbed hematopoietic gene expression program, indicating strong robustness of primitive hematopoiesis during early embryogenesis.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping