The analysis of the survivorship curves in Drosophila melanogaster with D-GADD45 overexpression

It is well known that GADD45 overexpression in the nervous system leads to the increased longevity in Drosophila. In this study, we performed an approximation of survivorship curves in Drosophila with GADD45 overexpression using the Gompertz distribution. We showed that the life span prolongation is caused by the alteration of R parameter, reflecting the mortality rate at the beginning of adult life, and not by the alteration of another Gompertz distribution parameter, α, reflecting the exponentially growing mortality rate. In addition, we analyzed the survivorship curves in the case of radiation hormesis (the phenomenon of life span extension under the exposure to low doses of radiation) and confirmed the regularity stated above. On the basis of this regularity, we concluded it promising to search for geroprotectors among the substances decreasing the R parameter, which is easier to assess than the full survivorship curve.