Liposome-mediated gene transfer via sperm cells. High transfer efficiency and persistence of transgenes by use of liposomes and sperm cells and a murine amplification element

Plasmid DNA was encapsulated in liposomes to protect from degradation and to support the incorporation into sperm cells. Transgenic spermatozoa carry the foreign DNA to the target cell when fertilizing the egg. Several plasmid constructs were transferred into rabbits, cattle and chicken. The plasmid apparently can persist when provided with a murine amplification promoting sequence. The transgeneity of sperm cells as well as fetuses or offspring was demonstrated by dot blot, Southern blot analysis and PCR. Expression of the transgene was shown as enzymatic activities of the reporter genes SEAP or beta-galactosidase and by gelelectrophoretic characterization of the expressed gene products. The transfer efficiency and the persistence of the gene constructs is significantly increased due to the use of sperm cells as gene carriers mediated by liposomes and the amplification element.