[New approaches in developmental genetics and gene therapy: xenotransplantation of Drosophila embryonic nerve cells into the brain of vertebrate animals].

The author's studies dealing with xenotransplantations of the embryonic nervous tissue into the brain of amphibian and mammals are reviewed. Drosophila nerve cells have been shown to survive inside the brain, differentiate, form ganglion-resembling structure, and come into synaptic contact with the host tissue. The embryonic nerve cells of transgenic Delta mutants of Drosophila melanogaster carrying a gene of bacterial galactosidase (lacZ) were also transplanted into the brain of adult rats and then identified histologically by X-gal staining of brain sections for the lacZ-gene product. The xenografts were shown to survive in the host brain for at least 2-3 weeks, after which they were attacked by macrophages. No glial scar tissue formed around the site of the xenograft. Cotransplantation of Drosophila embryonic nerve cells and the homologous embryonic nerve tissue was favorable for homograft survival and development, because formation of the glial scar was blocked, whereas homograft vascularization and differentiation of its nerve cells were stimulated. The results obtained are of interest with regard to neurosurgery, because they may be used to prevent formation of glial scar, an important factor in successful neurotransplantation.