Abstract |
A recombinant plasmid (C357;3.5 Mdal) containing heterologous DNA(pBR322(2.6 Mdal) with cDNA for an egg yolk protein from Drosophila grimshawi) in Escherichia coli strain HB 101 survived in and was recovered on selective media from sterile and nonsterile soil during 27 days at frequencies similar to those of the E. coli(pBR322) system. In sterile saline, the numbers of all cells decreased during 34 days, but the numbers of the plasmidless host declined less. There was no selective loss of the heterologous DNA in either soil or saline, as determined by colony hybridization with a 32P-labeled DNA probe for the cDNA, but the HB101(C357) appeared to be less able than HB101(pBR322) to cope with conditions of starvation. These results suggested that nonessential eucaryotic DNA inserted into plasmid DNA has little effect on the survival in soil or saline of the bacterial host and the maintenance of the vector. (Copyright (c) 1986, Springer-Verlag New York, Inc.) |