Genetic mosaic analysis indicates that the bulb region of coat hair follicles contains a resident population of several active multipotent epithelial lineage progenitors.

摘要: The hair follicle represents an excellent model system for exploring the properties of lineage-forming units in a dynamic epithelium containing multiple cell types. During its growth (anagen) phase, proximal-distal axis mouse coat (pelage) provides historical record all epithelial lineages generated from resident stem population. An unresolved question field is whether bulb region anagen pelage follicles contains multipotential progenitors and their individual contribution to cellular census fluctuates over time. To address this issue, chimeric were harvested midanagen three types genetic mosaic models. Analysis distribution genotypic markers, including digital three-dimensional reconstruction serially sectioned follicles, revealed that on average four or fewer active progenitors, each capable giving rise six follicular fates. Moreover, analysis pelage, as well cultured whisker provided evidence bulb-associated can give expanding descendant clones during midanagen, leading conclusion dormant symmetrically dividing cells. This latter feature resembles behavior hematopoietic cells after bone marrow transplantation, raises property may be shared by other self-renewing epithelia.