Distinct mechanisms of life expectancy reduction in cells and organisms exposed to certain weak external stimuli.

The results of many years of research involving biological objects of various organization levels are summarized in the present review. A distinct species-nonspecific form of negative influence of external signals on the life expectancy of cells associated with programmed damage to cell populations is discussed. The effect was found to follow low-dose irradiation, radiochemical treatment, and thermal treatment; it led to an accelerated extinction of postmitotic populations, which may cause a decrease of life expectancy of multicellular organisms. The possibility of inheritance of the effect upon asexual and sexual reproduction was demonstrated. Epigenetic mechanisms are supposed to underlie the phenomenon. [ABSTRACT FROM AUTHOR]