Expression of the A-raf proto-oncogene in the normal adult and embryonic mouse

We have determined the expression pattern of the A-raf proto-oncogene in th e embryonic and adult mouse, Western blot analysis of protein lysates from tissues of adult mice show that p69(A-raf) is ubiquitously expressed, but t hat levels of expression vary among different tissues. To determine the cel l-specific expression pattern of A-raf, we generated transgenic mice expres sing the p-galactosidase reporter gene from the A-raf promoter. We show tha t A-raf expression is highly specific within a given tissue, and we identif y cell types expressing this gene in the adult testis, epididymis, vas defe rens, seminal vesicle, ovary, oviduct, bladder, kidney, intestine, heart, s pleen, thymus, and cerebellum. In the embryo, ubiquitous expression of the reporter gene is observed, but the highest levels of expression are specifi cally detected in the embryonic heart at stages 9.5-11.5 days postcoitum.