The generation of a Bcl11a lineage tracing mouse model

The transcription factor B-cell lymphoma/leukaemia 11A (BCL11A) has essential functions in physiological processes as well as haematological and solid malignancies, however, its contribution to tissue development and tumour progression is poorly understood. Here we show the generation of a Bcl11a lineage tracing mouse model to allow for in vivo tracking of Bcl11a-expressing cells and their progeny. We validate the model in the mammary gland by using flow cytometry and whole-tissue 3D imaging to locate labelled cells after induction of tracing in early development. We show that Bcl11a is predominantly expressed in long-lived luminal progenitors which populate mammary alveoli upon pregnancy, confirming bona fide labelling of Bcl11a cells. The Bcl11a lineage tracing mouse model therefore provides a powerful resource to study Bcl11a cells in development, homeostasis, and cancer.