EXTRACHROMOSOMAL LOCALIZATION AND HEREDITARY TRANSFER OF A RECOMBINANT PLASMID MICROINJECTED INTO SILKWORM EGGS

The plasmid pl.5LTR, containing DNA copies of long terminal repeats of Rous sarcoma virus, was inserted into early silkworm embryos. Three g enerations of animals containing the introduced plasmid sequences in t heir total DNA were obtained. We demonstrated that exogenous DNA is re presented in the form of extrachromosomal molecules, whose molecular w eight exceeds the molecular weight of the original plasmid. In insects of the F0 generation, the structure of extrachromosomal DNA differs f rom that of the injected plasmid. Further rearrangement of the transge nes occurred during the hereditary transmission.