Figure 3.
Adult stem cells derived from each germ lineage exhibit different degrees of circadian function. Four body parts (brain, intestine, bone marrow, and skin) containing adult stem cell niches are shown. Each stem cell type is color coded by developmental lineage: ectoderm (red), neural crest (purple), mesoderm (green), or endoderm (blue). The lines adjacent to each stem cell type indicate either the presence (sine wave) or absence (straight line) of the circadian TTFL in those cells. Abbreviations: EKSC, epidermal keratinocyte stem cell; HFSC, hair follicle stem cell; HSC, hematopoetic stem cell; ISC, intestinal stem cell; MnSC, melanocyte stem cell; MSC, mesenchymal stem cell; NSC, neural stem cell; TTFL, transcriptional-translational feedback loop.