title: A GCSFR/CSF3R zebrafish mutant models the persistent basal neutrophil deficiency of severe congenital neutropenia.
abstract: Granulocyte colony-stimulating factor (GCSF) and its receptor (GCSFR), also known as CSF3 and CSF3R, are required to maintain normal neutrophil numbers during basal and emergency granulopoiesis in humans, mice and zebrafish. Previous studies identified two zebrafish CSF3 ligands and a single CSF3 receptor. Transient antisense morpholino oligonucleotide knockdown of both these ligands and receptor reduces neutrophil numbers in zebrafish embryos, a technique widely used to evaluate neutrophil contributions to models of infection, inflammation and regeneration. We created an allelic series of zebrafish csf3r mutants by CRISPR/Cas9 mutagenesis targeting csf3r exon 2. Biallelic csf3r mutant embryos are viable and have normal early survival, despite a substantial reduction of their neutrophil population size, and normal macrophage abundance. Heterozygotes have a haploinsufficiency phenotype with an intermediate reduction in neutrophil numbers. csf3r mutants are viable as adults, with a 50% reduction in tissue neutrophil density and a substantial reduction in the number of myeloid cells in the kidney marrow. These csf3r mutants are a new animal model of human CSF3R-dependent congenital neutropenia. Furthermore, they will be valuable for studying the impact of neutrophil loss in the context of other zebrafish disease models by providing a genetically stable, persistent, reproducible neutrophil deficiency state throughout life.
authors.affiliation: Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Vahid
authors.initials: V
authors.lastname: Pazhakh
authors.affiliation: Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Sharon
authors.initials: S
authors.lastname: Clark
authors.affiliation: Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Keightley
authors.affiliation: Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria 3800, Australia.
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Lieschke
mesh_terms: D000818:Animals; D001483:Base Sequence; D064113:CRISPR-Cas Systems; D000080984:Congenital Bone Marrow Failure Syndromes; D004195:Disease Models, Animal; D004625:Embryo, Nonmammalian; D005091:Exons; D000072669:Gene Editing / Q000379:methods*; D015870:Gene Expression; D016179:Granulocyte Colony-Stimulating Factor / Q000235:genetics* / Q000276:immunology; D057895:Haploinsufficiency; D006579:Heterozygote; D006801:Humans; D007668:Kidney / Q000276:immunology / Q000473:pathology*; D007958:Leukocyte Count; D060172:Morpholinos / Q000235:genetics / Q000378:metabolism; D009503:Neutropenia / Q000151:congenital* / Q000235:genetics / Q000276:immunology / Q000473:pathology; D009504:Neutrophils / Q000276:immunology / Q000473:pathology*; D010641:Phenotype; D016184:Receptors, Colony-Stimulating Factor / Q000037:antagonists & inhibitors / Q000172:deficiency / Q000235:genetics* / Q000276:immunology; D015027:Zebrafish
chemical_list: D060172:Morpholinos; D016184:Receptors, Colony-Stimulating Factor; D016179:Granulocyte Colony-Stimulating Factor