Slow growth phenotype - A possible approach to improved plasmid maintenance in Saccharomyces cerevisiae

Abstract

Transformation-induced slow growth phenotype (SGP) in yeast is repressed in the presence of 21.tm plasmids. A full 2~m-sequence-based recombinant plasmid (pJB502) was found to be more stable in a 21.tm-free-[cir °] strain of Saccharomyces cerevisiae than in a cir + strain. This could not be attributed to differences in growth rate calculated from kinetic analysis of plasmid loss, but transformed [cir °] isolates, which had lost the recombinant plasmid, exhibited varying degrees of SGP in batch culture. One of these isolates was outcompeted in chemostat culture by the recombinant-plasmid-containing strain, suggesting that improved plasmid maintenance can result from SGP in cir ° hosts.

A Study of Long-Term Effects on Plasmid-Containing Escherichia coli in Carbon-Limited Chemostat Using 2D-Fluorescence Spectrofluorimetry

“…Already in the early 1980s Imanaka and Aiba (1981) (1) addressed this problem and presented a plasmid stability model, which has been widely used and improved by different groups (2–6). Other groups have studied the mechanisms behind plasmid instability (7–10), and the effects of growth conditions such as medium composition and growth rate on plasmid stability have also been investigated (11, 12). In their pioneering work, Imanaka and Aiba (1981) proposed different options to ensure the stability of the recombinant organism, and the problem has been addressed by several groups also mere recently (e.g., 13–15).…”