An RNAi screen unveils a new player in stem cell self-renewal and long-term regeneration

Mouse hair follicles undergo synchronized cycles. Cyclical regeneration and hair growth is fueled by stem cells (SCs). Following hair regeneration, SCs within the bulge and its vicinity (upper ORS which becomes the bulge for the next cycle) briefly self-renew to replenish expended SCs and ensure long-term tissue regeneration. We used microarrays to detect the relative levels of global gene expression influenced by transcription factor Tbx1 in order to gain insight into how Tbx1 is invovled in regulating hair follicle SC self-renewal and long-term regeneration. Fourty eight hours after deplicaiton induced hair regeneration, hair follicle SCs were FACS-purified for RNA extraction and hybridization on Affymetrix microarrays. To obtain homogeneous populations of expression profiles, we applied FASC technique to purify SC according to their cell surface markers.