CELL-PROLIFERATION IN RETINAL TRANSPLANTS

The MIB-1 antibody against a nuclear protein Ki-67 was used to study t he proliferation of cells in the rabbit retinal transplants, Fragmente d pieces of embryonic day 15 rabbit retinas were transplanted into the subretinal space of adult rabbits and allowed to survive for differen t times, Fragmented donor tissue starts organizing in rosettes 1 day a fter transplantation. The transplanted cells continue to proliferate i n the host eye and their pattern of proliferation resembles that of no rmal developing retina, suggesting that the factors responsible for th e proliferation pattern are preserved after transplantation. The divid ing cells in metaphase line up in the luminal layers of the rosettes, Certain cells become postmitotic in the regions corresponding to the i nner retina first, followed by the cells in the luminal layers of rose ttes, Cells in the regions between the rosettes, corresponding to the inner nuclear layer, presumably the Muller cells, proliferate signific antly for the equivalent age of postnatal day 2, Few cells in these re gions proliferate for at least the equivalent age of postnatal day 11 in transplants. There is a layer of nonproliferating, degenerating cel ls in the transplant situated close to the host retina, However, some cells in this layer, situated at the host-graft interface, proliferate . These cells proliferate for a long time possibly indicating gliosis. (C) 1997 Elsevier Science Inc.