Adults mammary stem cells in cow's milk: new perspectives and future challange

The discovery of the presence of stem cells and precursors with high regenerative potential in the mammary gland, hy- pothetically maintained throughout the course of the produc- tive life of the dairy cow sheds an interesting perspective in the research which is interested to clarify all physiological clues and possible solutions to increase or maintain longer the po- tential production of dairy cows during life span of lactation. In 2006, Connie Eaves’ lab in Vancouver (Stingl et ., 2006) [1] and Jane Visvader in Victoria (AU) (Schackleton et al., 2006) [2] have published the discovery of single mammary stem cells can repopulate the alveolar functional unit in mouse mam- mary gland. Later, bovine adult mammary stem cells have been functionally identified to regenerate alveoli that secrete milk [3,4]. Very recently it was described in human the pres- ence of breast stem cells in milk and this finding is now paving the way for investigation of the functions of these cells in the breastfed infant and the use of breast milk as a tool to under- stand the normal biology of the breast and its pathologies [5]. In dairy science these findings may be of great interest both from a scientific point of view and for possible future impacts on the economic chain of production of milk.