Fate-mapping mice: new tools and technology for immune discovery.

The fate-mapping mouse has become an essential tool in the immunologist's toolbox. Although traditionally used by developmental biologists to trace the origins of cells, immunologists are turning to fate-mapping to better understand the development and function of immune cells. Thus, an expansion in the variety of fate-mapping mouse models has occurred to answer fundamental questions about the immune system. These models are also being combined with new genetic tools to study cancer, infection, and autoimmunity. In this review, we summarize different types of fate-mapping mice and describe emerging technologies that might allow immunologists to leverage this valuable tool and expand our functional knowledge of the immune system. Fate-mapping mice have revealed the developmental origins of multiple types of immune cells. When combined with technologies such as single cell RNA sequencing (scRNAseq), multiphoton imaging, and multiparameter flow cytometry, fate-mapping mice can define novel cell populations. When used in the context of infection and cancer, fate-mapping mice can both aid in understanding immune cell responses and help uncover new putative therapeutic targets that are unique to cells of specific developmental origins. Emerging fate-mapping models take advantage of newer genetic tools, such as cellular barcoding and stochastic multicolor reporters, thus allowing further resolution of the dynamics of immune cell populations in mice. [ABSTRACT FROM AUTHOR]