EXPRESSION AND REGULATION OF HFIX MINIGENE AND CDNA DRIVEN BY BETA-CASEIN GENE IN MOUSE MAMMARY-GLAND

Mammary gland specific expression vectors for human clotting factor IX (hFIX) and LacZ reporter gene driven by bovine p-casein gene were con structed. Vectors were packaged by stearylamine (SA) liposome and were transferred to lactating mice via tail vein. Both hFIX and LacZ gene could be expressed in the mammary gland of the treated mice. The highe st production of hFIX protein was 80.28 ng per mt milk, and more than 85 % of hFIX protein appeared to be gamma-carboxylation and biological ly active. The results suggested that the 2.0 kb sequence of p-casein gene including promoter, exon 1 was effective to drive hFIX gene expre ssion in mammary gland and intron 1 of p-casein gene had an effect on the tissue specific expression. The expression level in mouse milk inj ected with hFIX minigene vector containing hFIX endogenous intron 1 wa s increased by above 3 times of that injected with hFIX cDNA vector.