Quiescence

Zhang et al. use single-cell RNA sequencing and functional analyses to describe the hyaluronic acid–GPRC5C signalling axis as an essential component controlling the state of dormancy for human and mouse haematopoietic stem cells.

Skeletal muscle stem cells are actively maintained in quiescence, but can activate quickly upon extrinsic stimulation. Here the authors show that CPEB1 promotes muscle stem cell activation by reprogramming the translational landscape.

Drosophila enter adult reproductive diapause in low temperatures and short day, halting ovarian development yet preserving fertility. Here the authors show that ovarian arrest in diapause is distinct from other stress responses and that despite DNA damage and decreased division, germline stem cells recover.

Adult neural stem cells are derived from an embryonic population of slowcycling progenitor cells, though how reduced cycling speed leads to establishment of the adult population has remained elusive. Here they show that non-oscillatory Notch-Hey signaling induced by slow-cycling contributes to long term maintenance of neural stem cells.

Using live imaging, the study shows, in mice, that epithelial cells escape from the hair follicle stem cell compartment during aging. Stem cell escape is associated with reduced cell adhesion and extracellular matrix gene expression and leads to hair follicle miniaturization.