The development of a technique that allows for oocyte and early embryo manipulation is one of the major scientific endeavors in the field of genetic manipulation for animal disease models, basic science in gene regulation and commercial applications. Dr. Ralph Brinster is one of the most prestigious scientists in the development of this science. Through his direction and support, the undertaking of the mechanisms that are involved in the earlier stages of embryology have been productive and enlightening. This paper outlines just some of the experimental successes that evolved from Dr. Brinster's insight and mentorship of one of his pupils. The essay outlines several experimental approaches that have contributed to this field. Specifically, it addresses how the mouse oocyte and the zygote respond to messenger RNA when introduced into the cell, in comparison to comparable non-mammalian species embryos. In addition, this paper discusses some transgenic animal models, both from a basic science point of view and a commercial extension of these techniques. This extension of Dr. Brinster's pioneering work is through technology that allows for the introduction of foreign DNA that can be expressed in targeted organs, such as the mammary gland for production of pharmaceuticals for use in clinical applications.