title: [Microglia arise from extra-embryonic yolk sac primitive progenitors].
abstract: Microglia are the resident macrophage population of the central nervous system (CNS). Adequate microglia function is crucial for the homeostasis of the CNS in health and disease, as they represent the first line of defence against pathogens, contributing to immune responses, but are also involved in tissue repair and remodeling. It is therefore crucial to better understand microglia origin and homeostasis. Much controversy remains regarding the nature of microglial progenitors, as the exact contribution and persistence of embryonic and post-natal hematopoietic progenitors to the adult microglial pool in the steady state remained unclear. In this study, we show that post-natal hematopoietic progenitors do not significantly contribute to microglia homeostasis in the adult brain in mice. In vivo lineage tracing studies established that adult microglia derives from primitive hematopoietic progenitors that arise before embryonic day 8. These results identify microglia as an ontogenically distinct population in the mononuclear phagocyte system and have implications for the use of embryonically-derived microglial progenitors for the treatment of various brain disorders.
authors: Singapore immunology network , Agency for science, technology and research, Immunos, Biopolis, Singapour. florent_ginhoux@immunol.a-star.edu.sg
authors: Florent
authors: F
authors: Ginhoux
authors: Miriam
authors: M
authors: Merad
mesh_terms: D000818:Animals; D020296:Animals, Congenic; D002454:Cell Differentiation; D019070:Cell Lineage; D050676:Core Binding Factor Alpha 2 Subunit / Q000502:physiology; D005260:Female; D017930:Genes, Reporter; D006411:Hematopoiesis, Extramedullary / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D019426:Integrases; D008099:Liver / Q000166:cytology / Q000196:embryology; D008648:Mesoderm / Q000166:cytology; D051379:Mice; D017628:Microglia / Q000166:cytology*; D008954:Models, Biological; D011247:Pregnancy; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013629:Tamoxifen / Q000494:pharmacology; D015017:Yolk Sac / Q000166:cytology*
chemical_list: D050676:Core Binding Factor Alpha 2 Subunit; D011993:Recombinant Fusion Proteins; C493726:Runx1 protein, mouse; D013629:Tamoxifen; C045073:Cre recombinase; D019426:Integrases