Dual ifgMosaic: A Versatile Method for Multispectral and Combinatorial Mosaic Gene-Function Analysis

Improved methods for manipulating and analyzing gene function have provided a better understanding of how genes work during organ development and disease. Inducible functional genetic mosaics can be extraordinarily useful in the study of biological systems; however, this experimental approach is still rarely used in vertebrates. This is mainly due to technical difficulties in the assembly of large DNA constructs carrying multiple genes and regulatory elements and their targeting to the genome. In addition, mosaic phenotypic analysis, unlike classical single gene-function analysis, requires clear labeling and detection of multiple cell clones in the same tissue. Here, we describe several methods for the rapid generation of transgenic or gene-targeted mice and embryonic stem (ES) cell lines containing all the necessary elements for inducible, fluorescent, and functional genetic mosaic (ifgMosaic) analysis. This technology enables the interrogation of multiple and combinatorial gene function with high temporal and cellular resolution. [Display omitted] •Dual ifgMosaic enables the study of the function of multiple genes in the same tissue•Imaging of up to 15 different cell populations expressing a unique set of genes•Dual ifgMosaic enables combinatorial epistasis analysis at single-cell resolution•Open-source DNA engineering strategy that simplifies the generation of genetic mosaics Multiple strategies are developed to enable multispectral and combinatorial mosaic gene-function analysis in mice, allowing comparison of molecular phenotypes on a cell-by-cell basis.