ABSTRACT
In 1971 Brackett et al., reported the first evidence of the uptake of a heterologous genome by mammalian spermatozoa. In 1989 Lavitrano et al., attracted widespread attention from the scientific as well as public community. The basic principle of sperm-mediated gene transfer is a coincubation of the DNA fragments in the sperm suspension. The fate of foreign DNA associated with sperm following in vitro fertilization has been determined to some extent in several species. There is ample evidence, that foreign DNA associates with specific regions of the sperm heads of several mammalian species. In cattle and mice uptake and internalization of the associated DNA into the sperm head have been shown. Only very limited additional information on the sperm-DNA uptake and transport into eggs has emerged in the last years.
