Effects on eye color mediated by DNA injection into Drosophila embryos

Fate of DNA injected into early Drosophila embryos

Plasmid DNA injected into early Drosophila embryos becomes enclosed in nuclei or nucleus-like structures where it remains at least throughout embryonic development. The fraction remaining in the cytoplasm is gradually degraded. The nuclear fraction is converted to a high-molecular-weight form consisting largely but not exclusively of tandem oligomers. Some of it, however, can occasionally become integrated in the genome. Extensive DNA replication takes place but few, if any, molecules are able to initiate a second round of replication.

Alteration of the gene for xanthine dehydrogenase in Drosophila following treatment with wildtype DNA

Microinjection of whole genome DNA into Drosophila embryos can result in a variety of changes to the host genome. In the experiments reported here, wildtype DNA is injected into mutant animals lacking xanthine dehydrogenase activity by virtue of a mutation in the structural gene for the enzyme, the rosy gene. Animals with wildtype eye pigmentation and normal levels of xanthine dehydrogenase result from the treatment. Analysis of the electrophoretic mobility of the enzyme in the altered stocks indicates, in four of five cases, that the restoration of activity coincides with changes in electrophoretic mobility. The changes which occur are consistent with acquisition of sequence from the donor DNA and, in two cases, provide evidence for recombination between homologous sequences.