HORMONAL REPLACEMENT THERAPY IN FISH - HUMAN GROWTH-HORMONE GENE-FUNCTION IN HYPOPHYSECTOMIZED CARP

Transgenic common carp, Cyprinus carpio, produced by the microinjectio n of fertilized eggs with a linearized chimeric plasmid pMThGH, a huma n growth hormone (hGH) gene with a mouse metallothionein-I (MT) gene p romoter in pBR322, were used to produce F1 and F2 transgenics. Followi ng hypophysectomy of the transgenic F2 common carp, non-transgenic com mon carp and non-transgenic crucian carp, growth was monitored for up to 110 days. In addition, recombinant hGH was injected subcutaenously into a group of the non-transgenic crucian carp. Growth rate analyses indicated that (1) hypophysectomy of non-transgenic common carp and cr ucian carp results in the cessation of growth, (2) hGH administration can stimulate the growth of hypophysectomized crucian carp and (3) hyp ophysectomized hGH-transgenic common carp continue to grow in the abse nce of their own growth hormone, suggesting that the hGH-transgene is being expressed in tissues other than the pituitary.