title: Podocin-green fluorescence protein allows visualization and functional analysis of podocytes.
abstract: Podocytes do not remain fully differentiated when cultured, and they are difficult to image in vivo, making the study of podocyte biology challenging. Zebrafish embryos are transparent and develop a single, midline, pronephric glomerulus accessible for imaging and systematic functional analysis. Here, we describe a transgenic zebrafish line that expresses green fluorescence protein (GFP) from the zebrafish podocin promoter. The line recapitulates the endogenous pronephric podocin expression pattern, showing GFP expression exclusively in podocytes starting 2 days postfertilization. Using the podocyte GFP signal as a guide for dissection, we examined the pronephric glomerulus by scanning electron microscopy; the surface ultrastructure exhibited fine, interdigitating podocyte foot processes surrounding glomerular capillaries. To determine whether the GFP signal could serve as a direct readout of developmental abnormalities or injury to the glomerulus, we knocked down the podocyte-associated protein crb2b; this led to a loss of GFP signal. Thus, podocin-GFP zebrafish provide a model for ultrastructural studies and in vivo visualization and functional analysis of glomerular podocytes. This model should also be useful for high-throughput genetic or chemical analysis of glomerular development and function.
authors.affiliation: Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 171 77 Stockholm, Sweden.
authors.forename: Bing
authors.initials: B
authors.lastname: He
authors.forename: Lwaki
authors.initials: L
authors.lastname: Ebarasi
authors.forename: Kjell
authors.initials: K
authors.lastname: Hultenby
authors.forename: Karl
authors.initials: K
authors.lastname: Tryggvason
authors.forename: Christer
authors.initials: C
authors.lastname: Betsholtz
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D007678:Kidney Glomerulus / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D050199:Podocytes / Q000166:cytology* / Q000378:metabolism* / Q000648:ultrastructure; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C407223:NPHS2 protein; D029961:Zebrafish Proteins; C513142:crb2b protein, zebrafish; D049452:Green Fluorescent Proteins