Germline transmission of an embryonic stem cell line derived from BALB/c cataract mice

Mice embryonic stem (ES) cells have enabled the generation of mouse strains with defined mutation(s) in their genome for putative disease loci analysis. In the study of cataract, the complex genetic background of this disease and lack of long-term self-renewal ES cells have hampered the functional researches of cataract-related genes. In this study, we aimed to establish ES cells from inherited cataract mice (BALB/CCat/Cat). Embryos of cataract mice were cultured in chemical-defined N2B27 medium with the presence of two small molecules PD0325901 and CHIR99021 (2i) and an ES cell line (named EH-BES) was successfully established. EH-BES showed long-term self-renewal in 2i medium and maintained capacity of germline transmission. Most importantly, the produced chimera and offspring developed congenital cataract as well. Flow cytometry assay revealed that EH-BES are homogeneous in expression of Oct4 and Rex1in 2i medium, which may account for their self-renewal ability. With long-term self-renewal ability and germline-competent, EH-BES cell line can facilitate genetic and functional researches of cataract-related genes and better address mechanisms of cataract.