[The incorporation of macromolecules into the germ cells of male mice via electroporation and dimethyl sulfoxide].

Electroporation (incorporation of macromolecules into the living cells by means of electric pulses) provides inclusion of plasmid 14C-DNA into immature cells of spermatogenic epithelium. The highest level of foreign DNA incorporation into spermatocytes and spermatids has been induced by 8kV electric pulses applied 3 times with 20 sec intervals. Meanwhile, mature sperms are found to be exclusively resistant to exogenous DNA irrespective of the voltage level, the number of pulses and Ca++ uptake (contents). Incubation of mature sperms for two hours in the medium with Ca++ (10 mM) and dimethylsulfoxide--(DMSO, 33%) provides highly reliable incorporation of plasmid 14C-DNA into sperm heads. The sperm cells with foreign DNA incorporated by means of Ca++ and DMSO treatment still remain alive and mobile. The possibilities of mature sperms loaded with foreign DNA for the creation of transgenic mammals are discussed.