Fertilizing capacity of transgenic and non-transgenic rabbit spermatozoa after heterospermic insemination

The aim of this study was to evaluate fertilizing capacity of transgenic and non-transgenic rabbits from 3 rabbit breeds (NZW, Californian and Marder) after heterospermic insemination using phenotypic (white, black and white, and blue) and genotypic (transgene - hFVIII gene) markers. Semen from males was used to make pools of 3 males (one of each breed) and to perform heterospermic insemination. Insemination was carried out in hormonally treated young females with about 10 million of spermatozoa per insemination dose (1.0 ml). Although each female was inseminated with approximately the same number of spermatozoa, sperm from one transgenic male (NZW) was dominant, significant difference was observed in the offspring among the males with similar semen quality (53% vs. 30-17%, P<0.01-0.001). Based on our results we can conclude that transgenesis had no effect on fertilizing capacity of transgenic spermatozoa during heterospermic insemination.