ESTROGEN-INDUCIBLE AND LIVER-SPECIFIC EXPRESSION OF THE CHICKEN VERY LOW-DENSITY APOLIPOPROTEIN-II GENE LOCUS IN TRANSGENIC MICE

We have examined the chicken Very Low Density Apolipoprotein II (apoVL DL II) gene locus in transgenic mice. A DNA fragment composed of the t ranscribed region, 16 kb of 5' flanking and 400 bp of 3' flanking sequ ences contained all the information sufficient for estrogen-inducible, liver-specific expression of the apoVLDL II gene. The far-upstream re gion contains a Negative Regulating Element coinciding with a DNasel-h ypersensitive site at -11 kb. In transgenic mice, the NRE at -11 kb is used for downregulating the expression to a lower maximum level. The NRE might be used for modulating apoVLDL II gene expression, and may b e involved in the rapid shut-down of the expression after hormone remo val.