A reserve stem cell population in small intestine renders Lgr5 -positive cells dispensable

摘要: The small intestine epithelium renews every 2 to 5 days, making it one of the most regenerative mammalian tissues. Genetic inducible fate mapping studies have identified two principal epithelial stem cell pools in this tissue. One pool consists columnar Lgr5-expressing cells that cycle rapidly and are present predominantly at crypt base. other Bmi1-expressing largely reside above However, relative functions these their interrelationship not understood. Here we specifically ablated mice using a human diphtheria toxin receptor (DTR) gene knocked into Lgr5 locus. We found complete loss did perturb homeostasis epithelium, indicating types can compensate for elimination population. After ablation cells, progeny production by increased, cells. Indeed, lineage tracing showed gave rise pointing hierarchy intestinal epithelium. Our results demonstrate dispensable normal homeostasis, absence serve as an alternative pool. These data provide first experimental evidence between populations. may represent both reserve case injury source replenishment under non-pathological conditions.