preliminary studies directed to the application of growth hormone gene therapy to Arapaima gigas

Abstract

The "Pituitary Hormones Research Group" at the Biotechnology Center of IPEN-CNEN / São Paulo has already published several works on techniques of Gene Therapy of growth, which is based on the injection of human (hGH) or mouse growth hormone (mGH) genes in the muscle of dwarf mice, followed by electroporation. In parallel, the same Group dedicated to the cloning, expression and characterization of pituitary hormones of the giant Amazonian fish "Arapaima gigas" (Pirarucu) including the synthesis and phylogenetic analysis of gonadotropins (agFSH and agLH) and now, the cDNA partial cloning of agGH and agTSH. After the same group carried out fieldwork in the "Piscicultura Raça" (Canabrava do Norte, MT), in collaboration also with the "Embrapa Pesca e Aquicultura" (Palmas, TO), it was found that one of the priorities of the Pirarucu´s breeders is the possible treatment with the growth hormone (agGH) itself, in order to improve aspects such as growth, reproduction in captivity and muscle mass increase. It was concluded that our gene therapy technique, already standardized in mice, could be effective for this purpose, considering that, obviously, injectable agGH is not yet available and that repeated injections have already been shown to be extremely stressful in this species, affecting for example food intake. The present work proposes to standardize the technique in juveniles Arapaima gigas of 5 kg (age 180 days), studying the best therapeutic conditions and determining the levels of circulating agGH in 7-day (short term) and 30-day (long term) bioassays. The work will be carried out in collaboration with the mentioned groups of Palmas (TO) and Canabrava do Norte (MT). The positive results acquired in this study should pave the way to future treatment protocols to be performed on this same species of fish. (AU)