A Novel Tmem119-tdTomato Reporter Mouse Model for Studying Microglia in the Central Nervous System

• DOI: 10.1101/665893
• Publication Date: 2019-06-10T17:45:11Z
• Authors: Chunsheng Ruan; Linlin Sun; Alexandra Kroshilina; Lien Beckers; Philip L. De Jager; Elizabeth M. Brad...; Samuel Hasson; Guang Yang; Wassim Elyaman
• Keywords: Immunofluorescence; NeuN

Abstract Microglia are resident immune cells of the central nervous system (CNS). The exact role microglia in physiopathology CNS disorders is not clear due to lack tools discriminate between and infiltrated innate cells. Here, we present a novel reporter mouse model targeting microglia-specific marker (TMEM119) for studying function health disease. By placing cassette (GSG-3xFlag-P2A-tdTomato) coding sequence exon 2 3’UTR Tmem119 gene using CRISPR/Cas9 technology, generated Tmem119-tdTomato knock-in strain. Gene expression assay showed no difference endogenous mRNA level tdTomato/+ relative control Wild-type mice. expressing tdTomato-were recognized by immunofluorescence staining commercially available anti-TMEM119 antibodies. Using flow cytometry techniques, tdTomato + were detected throughout CNS, but peripheral tissues adult In addition, aging does seem influence TMEM119 as detectable older mice (300 540 days old). Further characterization shows that highly colocalized with Iba1 (microglia macrophages) brain, NeuN- (neurons), GFAP- (astrocytes) or Olig2- (oligodendrocytes) labeled Moreover, analysis brain demonstrates majority microglial CD45 low CD11b (96.6%) positive. Functionally, laser-induced injury model, measured time-lapse activation tdTomato-labeled transcranial two-photon microscopy live Taken together, will serve valuable tool specifically study