Expression of human α1 antitrypsin in transgenic sheep

We have recently described the production of large amounts (≤W5 grams per litre) of enzymatically active human alpha 1 antitrypsin in the milk of transgenic sheep (Wrightet al., 1991). Here, we describe in more detail the expression of the human protein in the milk of these animals throughout the lactation period. Human alpha 1 antitrypsin is also found at much lower levels in the plasma of transgenic ewes before, during and after lactation. It is also detected in male plasma at very low levels.