An expression profile of human alpha-lactalbumin in the milk of transgenic mouse.

Five female transgenic mice were produced by microinjection using a construct made up of a 7.3-kb-5' flanking region and a 2.0-kb coding region of human alpha-lactalbumin, as well as a 227-bp 3'-flanking region from bovine growth hormone gene. A founder female expressed human alpha-lactalbumin as much as 0.3 g per liter of its milk, approximately a 3-fold increase in the total alpha-lactalbumin concentration of the transgenic mouse milk. Compared with the normal mice, the expression profile of the halpha-Lac transgene in the transgenics is different during the lactation, showing low level in the first 3 days and becoming increased from day 4, then gradually reaching and stabilizing at the highest level from day 13. In addition, the milk yielding volume in the transgenics tended to be higher than in normal mice, suggesting higher concentrations of alpha-lactalbumin might boost more milk output.