Adaptive Response in Mouse Embryos?

Pre-implantation embryos of the mouse were studied for the occurrence of an adaptive response, i.e. induction of radio-resistance by a previous low dose. Various experimental designs were checked (initial doses between 3 and 10 cGy; second dose 2-6 Gy at 6-24 h after the first dose). Some of the experiments were carried out in exactly the same way that resulted in an adaptive response of human lymphocytes reported previously. However, when cell proliferation and differentiation of mouse embryos were examined, none of the conditions tested indicated the induction of an adaptive response.