Elucidation of the mammary stem cell hierarchy (360G-Wellcome-105377_Z_14_Z)

The mammary gland is a dynamic organ with many cycles of proliferation and death throughout both oestrus cycling and pregnancy. This capacity of the mammary gland for rapid growth and regeneration has been attributed to mammary stem cells (MaSCs). Despite extensive efforts over the past 60 years, definitive characterization of the MaSC, its localisation, and hierarchy, has yet to be achieve and there is still much disagreement regarding the nature and identity of mammary stem cells. Here, I propose to utilise a triad of novel techniques to unequivocally elucidate the mammary stem cell hierarchy. I will utilise continuous clonal labeling as a completely neutral approach for the labelling of a single cell and its daughters. This will be combined with optical clearing techniques and advanced imaging, giving the ability to image the entire mammary epithelial tree in three dimensions, using both fluorescent reporter genes and antibody labelling. Using these techniques, I will investigate clonally marked regions throughout the development of the mammary gland, from puberty into adulthood. This proposed program of research aims to ensure that significant progress is made in the unequivocal identification of the potential of MaSCs coupled with their localization and characterisation.