ISOLATION OF A GERMLINE-TRANSMISSIBLE EMBRYONIC STEM (ES) CELL-LINE FROM C3H HE MICE/

We have isolated three embryonic stem (ES) cell lines from C3H/He mice using mouse STO cells as a feeder layer. One ES cell line (H-1) was m ale, and two (H-2 and H-3) were female, as determined by polymerase ch ain reaction, in situ hybridization, and karyotype analyses. All were immunocytochemically reactive with a C3H strain-specific antibody. Inj ection of cells from the female ES H-3 line into C57BL/6 blastocysts y ielded four chimeras with slight coat color chimerism. All chimeras we re male, and as expected, no germline-transmission was observed. By co ntrast, when male ES H-1 cells were injected into the perivitelline sp ace of 8-cell C57BL/6 embryos, one male mouse with overt coat color ch imerism was recovered, and it produced ES H-1-derived offspring exclus ively. This germline-transmissible C3H/He cell line represents a novel addition to those ES lines currently employed for gene manipulation s tudies of development.