Study on the participation of neoplastic cells in the development of mouse embryos

To test the ability of cloned committed erythroleukemic cells to participate in development we have injected. Friend leukemia cells (FLC) into C57Bl/6 mouse blastocysts together with Friend leukemia virus (FLV) and we have examined the newborn individuals derived from them. Five animals out of 32 born have FLC-derived neoplasia. The incidence of neoplasia is increased as compared with other similar experiments without the virus. In two of the animals with the FLC neoplasia the disease manifestation is an erythroid leukemia similar to the one obtained directly with the virus in normal DBA/2 mice.