title: Genetic approaches identify adult pituitary stem cells.
abstract: Adult tissues undergo continuous cell turnover in response to stress, damage, or physiological demand. New differentiated cells are generated from dedicated or facultative stem cells or from self-renewing differentiated cells. Here we describe a different stem cell strategy for tissue maintenance, distinct from that observed for dedicated or facultative stem cells. We report the presence of nestin-expressing adult stem cells in the perilumenal region of the mature anterior pituitary and, using genetic inducible fate mapping, demonstrate that they serve to generate subsets of all six terminally differentiated endocrine cell types of the pituitary gland. These stem cells, while not playing a significant role in organogenesis, undergo postnatal expansion and start producing differentiated progeny, which colonize the organ that initially entirely consisted of differentiated cells derived from embryonic precursors. This generates a mosaic organ with two phenotypically similar subsets of endocrine cells that have different origins and different life histories. These parallel but distinct lineages of differentiated cells in the gland may help the maturing organism adapt to changes in the metabolic regulatory landscape.
authors.affiliation: Howard Hughes Medical Institute, Department of Medicine, University of California at San Diego School of Medicine, La Jolla, CA 92093-0648, USA.
authors.forename: Anatoli S
authors.initials: AS
authors.lastname: Gleiberman
authors.forename: Tatyana
authors.initials: T
authors.lastname: Michurina
authors.forename: Juan M
authors.initials: JM
authors.lastname: Encinas
authors.forename: Jose L
authors.initials: JL
authors.lastname: Roig
authors.forename: Peter
authors.initials: P
authors.lastname: Krasnov
authors.forename: Francesca
authors.initials: F
authors.lastname: Balordi
authors.forename: Gord
authors.initials: G
authors.lastname: Fishell
authors.forename: Michael G
authors.initials: MG
authors.lastname: Rosenfeld
authors.forename: Grigori
authors.initials: G
authors.lastname: Enikolopov
mesh_terms: D053687:Adult Stem Cells / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D049109:Cell Proliferation; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007381:Intermediate Filament Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D009419:Nerve Tissue Proteins / Q000378:metabolism; D064231:Nestin; D010903:Pituitary Gland, Anterior / Q000166:cytology*; D010911:Pituitary Neoplasms / Q000473:pathology
chemical_list: D007381:Intermediate Filament Proteins; D009419:Nerve Tissue Proteins; C577485:Nes protein, mouse; D064231:Nestin; D049452:Green Fluorescent Proteins