INTRODUCTION OF FOREIGN DNA INTO THE SPERMATOZOA OF FARM-ANIMALS

Mature sperm cells from eight animal species were incubated with cloned DNA to analyze their ability to associate DNA molecules. The spermatozoa from all the tested species were able to associate cloned DNA with biphasic kinetics. Bull, pig, buffalo, ram, goat, rooster and mouse sperm cells rapidly associated a portion of the foreign DNA during the first 15 to 30 min, while the carp spermatozoa required only 30 sec. The percentage of associated DNA molecules with respect to the total amount of DNA varied among the species: 2 to 10% (mouse), 7.6 to 10% (carp), 7.2 to 25% (rooster), 1.5 to 3% (bull), 0.07 to 0.1% (buffalo), 0.26 to 0.3% (pig), and 6.4 to 10% for ram and goat semen. The DNase I digestion assay was performed after the incubation of semen with the cloned DNA. Sixteen to twenty-two percent of labeled DNA remained associated with murine spermatozoa, while for carp spermatozoa, it ranged from 50 to 69%. The ability of mature sperm cells to associate DNA molecules is a peculiarity of living spermatozoa, and it is affected by the sperm motility and the DNA/sperm ratio. © 1990.