GROWTH HO OR PROMOTER pBR Figure 10.15 (a) These two mice are genetically the same strain, except that the one on the right has been transfected with the human growth hormone gene(shown in its circular plasma vector). The new gene spurr ed an Increase in this mouse's growth rate until it dwarfed its normal-sized companion. (b) Comparison of the meat from a pig into which bovine growth hormone genes were introduced (left) and a normal pig (right). A section taken at the same rib area of the two pigs indicates significantly reduced fat content in the transgenic pig. Both animals weighed approximately the same. (o Goat as drug factory. This normal-looking goat carries a human gene for synthesizing the cystic fibrosis transmembrane regulator (CFTR) protein. If tests go as planned, the CFTR will be marketed as a replacement factor for children with cystic fibrosis