Dormant Nfatc1 reporter-marked basal stem progenitor cells contribute to mammary lobuloalveoli formation

Abstract

The Mammary gland undergoes complicated epithelial remodeling to form lobuloalveoli during pregnancy, in which basal epithelial cells remarkably increase to form a basket-like architecture. However, it remains largely unknown how dormant mammary basal stem/progenitor cells involve in lobuloalveolar development. Here, we show that Nfatc1 expression marks a rare population of mammary epithelial cells with the majority being basal epithelial cells. Nfatc1 reporter-marked basal epithelial cells are relatively dormant mammary stem/progenitor cells. Although Nfatc1 reporter-marked basal epithelial cells have limited contribution to the homeostasis of mammary epithelium, they divide rapidly during pregnancy and contribute to lobuloalveolar development. Furthermore, Nfatc1 reporter-marked basal epithelial cells are preferentially used for multiple pregnancies. Using single-cell RNA-seq analysis, we identify multiple functionally distinct clusters within the Nfatc1 reporter-marked cell-derived progeny cells during pregnancy. Taken together, our findings underscore Nfatc1 reporter-marked basal cells as dormant stem/progenitor cells that contribute to mammary lobuloalveolar development during pregnancy.
Keywords: Biological sciences; Molecular physiology; Omics; Stem cells research.