Sexual reproduction as a response to H2O2 damage in Schizosaccharomyces pombe.
Although sexual reproduction is widespread, its adaptive advantage over asexual reproduction is unclear. One major advantage of sex may be its promotion of recombinational repair of DNA damage during meiosis. This idea predicts that treatment of the asexual form of a facultatively sexual-asexual eucaryote with a DNA-damaging agent may cause it to enter the sexual cycle more frequently. Endogenous hydrogen peroxide is a major natural source of DNA damage. Thus, we treated vegetative cells of Schizosaccharomyces pombe with hydrogen peroxide to test if sexual reproduction increases. Among untreated stationary-phase S. pombe populations the sexual spores produced by meiosis represented about 1% of the total cells. However, treatment of late-exponential-phase vegetative cells with hydrogen peroxide increased the percentage of meiotic spores in the stationary phase by 4- to 18-fold. Oxidative damage therefore induces sexual reproduction in a facultatively sexual organism, a result expected by the hypothesis that sex promotes DNA repair.
Bernstein
C
C
Department of Microbiology and Immunology, College of Medicine, University of Arizona, Tucson 85724.
Johns
V
V
D004260:DNA Repair; D004271:DNA, Fungal / Q000187:drug effects / Q000235:genetics; D006861:Hydrogen Peroxide / Q000633:toxicity*; D008540:Meiosis / Q000187:drug effects*; D012098:Reproduction / Q000187:drug effects; D004718:Saccharomycetales / Q000187:drug effects*; D012568:Schizosaccharomyces / Q000187:drug effects*; D013172:Spores, Fungal
D004271:DNA, Fungal; D006861:Hydrogen Peroxide