Derivation of a robust mouse mammary organoid system for studying tissue dynamics

• Published in: Development (Cambridge) Vol. 144; no. 6; pp. 1065 - 1071
• Main Authors: Jamieson, Paul R, Dekkers, Johanna F, Rios, Anne C, Fu, Nai Yang, Lindeman, Geoffrey J, Visvader, Jane E
• Format: Journal Article
• Language: English
• Published: England The Company of Biologists Ltd 15.03.2017
• Subjects: Animals; Basal cells; Cell culture; Cell fate; Cell Lineage; Clone Cells; Epithelial cells; Epithelial Cells - cytology; Female; Flow Cytometry; Genes, Reporter; Imaging, Three-Dimensional; Mammary gland; Mammary Glands, Animal - cytology; Mammary Glands, Animal - growth & development; Mice; Microscopy, Confocal; Milk; Organoids; Organoids - cytology; Rodents; Stem cells; Tissue Culture Techniques - methods; Clonality; Multicolor reporter mice; 3D imaging; Mammary organoids; Stem/progenitor cells; In vitro lineage tracing
• ISSN: 0950-1991; 1477-9129
• DOI: 10.1242/dev.145045

Advances in stem cell research have enabled the generation of 'mini organs' or organoids that recapitulate phenotypic traits of the original biological specimen. Although organoids have been demonstrated for multiple organ systems, there are more limited options for studying mouse mammary gland formation Here, we have built upon previously described culture assays to define culture conditions that enable the efficient generation of clonal organoid structures from single sorted basal mammary epithelial cells (MECs). Analysis of Confetti-reporter mice revealed the formation of uni-colored structures and thus the clonal nature of these organoids. High-resolution 3D imaging demonstrated that basal cell-derived complex organoids comprised an inner compartment of polarized luminal cells with milk-producing capacity and an outer network of elongated myoepithelial cells. Conversely, structures generated from luminal MECs rarely contained basal/myoepithelial cells. Moreover, flow cytometry and 3D microscopy of organoids generated from lineage-specific reporter mice established the bipotent capacity of basal cells and the restricted potential of luminal cells. In summary, we describe optimized conditions for the efficient generation of mouse mammary organoids that recapitulate features of mammary tissue architecture and function, and can be applied to understand tissue dynamics and cell-fate decisions.