Physiological Responses of Yeast Cells to UV of Different Wavelengths

Abstract

Liquid-holding recovery was investigated in diploid yeast after exposure to UV radiation of different wavelengths in the 254–313 nm range. It was found that the kinetics were wavelength dependent. Further experiments using a different technique showed that recovery was absent with 303- and 313-nm radiation, but was mimicked in liquid medium by divisions of surviving cells. This division may be facilitated by materials released from irradiated cells. This process is more pronounced with longer wavelengths. Cell progression was also studied by measuring budding and division delay. While 254-nm radiation induces division delays which are considerably greater than those for budding, suggesting an additional G2 block, this difference was not found with 313-nm radiation. With 303-nm radiation division was even less delayed than budding, suggesting a general distortion in the sequence of cellular events.