Figure 4.

Advancement of female puberty by the intrahypothalamic transplantation of cells genetically engineered to overexpress the TGFα gene. (Upper) Effect on puberty of the continuous production of TGFα after transplantation of cells bearing a recombinant PGKIRES-hTGFα retroviral construct in which expression of the TGFα gene is driven by a constitutively expressed promoter. (Lower) Transplantation of cells in which TGFα expression is under the control of an inducible promoter advances sexual maturation when the cells are implanted in the ME region of the hypothalamus, and expression of the TGFα gene is induced by daily injections of zinc chloride. O-POA, outside the POA; DAHA, region dorsal to the anterior hypothalamic area; O-ME, outside the ME. Numbers on top of bars are number of animals per group. Vertical lines are SEM. The O-POA and O-ME groups of PGKIRES-hTGFα-implanted rats each include two animals in which the implants could not be localized (see text).