This study aims to produce transgenic cattle expressing lysine-rich polypeptide in milk by somatic cell nuclear transfer. Lysine is the first limiting amino acid in cereal crops. Lysine deficiency leads to fatigue, nausea and reproductive disorders. In this study, transgenic cells with lysine-rich cDNA (β-casein, αS2-casein and lactotransferrin cDNA) were used as donor cells to produce transgenic cattle by somatic cell nuclear transfer. The transgene integration and expression in transgenic cattle were examined using western blotting, Southern blotting, PCR and RT-PCR. Our results showed that the lysine-rich gene was successfully integrated into the bovine genome and expressed in the mammary gland of transgenic cattle during lactation. The milk lysine concentrations of three transgenic cattle were higher than those of non-transgenic controls. The production of transgenic cattle expressing lysine-rich polypeptides in milk may provide a large-scale and cost-effective resource for lysine-rich products.
Keywords: Lysine-rich polypeptide; Milk; Somatic cell nuclear transfers; Transgenic cattle.