title: Defining the hematopoietic stem cell niche: the chicken and the egg conundrum.
abstract: Understanding the in vivo regulation of hematopoietic stem cells (HSCs) will be critical to identifying key factors involved in the regulation of HSC self-renewal and differentiation. The niche (microenvironment) in which HSCs reside has recently regained attention accompanied by a dramatic increase in the understanding of the cellular constituents of the bone marrow HSC niche. The use of sophisticated genetic models allowing modulation of specific lineages has demonstrated roles for mesenchymal-derived elements such as osteoblasts and adipocytes, vasculature, nerves, and a range of hematopoietic progeny of the HSC as being participants in the regulation of the bone marrow microenvironment. Whilst providing significant insight into the cellular composition of the niche, is it possible to manipulate any given cell lineage in vivo without impacting, knowingly or unknowingly, on those that remain?
authors.affiliation: St. Vincent's Institute of Medical Research, Department of Medicine at St. Vincent's Hospital, University of Melbourne, Victoria, Australia.
authors.forename: Sofie
authors.initials: S
authors.lastname: Singbrant
authors.forename: Maria
authors.initials: M
authors.lastname: Askmyr
authors.forename: Louise E
authors.initials: LE
authors.lastname: Purton
authors.forename: Carl R
authors.initials: CR
authors.lastname: Walkley
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006801:Humans; D051379:Mice; D055153:Stem Cell Niche / Q000166:cytology*