The aim of this study was to delete two genes from the genome of the fission yeast S. pombe in order to search for their functions in the cell. These genes are SPAC869.02c (MRI) and SPBC21C3.19 (MR2) and previous studies reported their significant induction after gamma irradiation. We carried out the deletions of the two genes and we replaced them with the selection marker ura4. Among the phenotype characteristics we tested the viability, the sexual behaviour and the radiosensitivity to ultraviolet and gamma irradiation. Our results indicate that MR1-deleted strain is sensitive to both UV and gamma irradiation, while the survival of the irradiated MR2-deleted strain doesn't appear to be influenced by the deletion. This suggests an involvement of MR1 gene in the adaptive response triggered by these types of genotoxic aggression. The comparison of MR1-d and MR2-d with the double deleted strains containing the deletion of MR1 or MR2 combined with the deletion of sty1 or rad3 genes led to a surprising result: the double mutants MR1-d sty1-d and MR1-d rad3-d were more resistant to both UV and gamma irradiation than the simple deleted strains sty1-d and rad3-d, respectively. This suggests a possible contribution of MR1 gene to the lethal process taking place in irradiated cells.