The effect of antisense oligonucleotides specific to mRNA of the proapoptotic gene harakiri (Hrk) on the development of mouse SAMP1 (senescence-accelerated mouse prone) and (C57BL/6J x DBA/2J)F1 preimplantation embryos cultured in vitro was investigated. The SAMP1 mice are characterized by genetically determined decrease of fertility along with the highly frequent perturbations of embryonic development. Reproduction indices of the (C57BL/6J x DBA/2J) hybrids lie within the normal range. Because of this, preimplantation abnormalities in this line were induced by the action of proapoptotic agent bleomycine. It was demonstrated that antisense inhibition of the Hrk expression had no effect on the frequency of genetically determined abnormalities of early embryonic development in SAMP1 mice. In case of induced abnormalities, addition of oligonucleotides specific to mRNA of proapoptotic Hrk gene influenced the number of abnormalities, and at the same time, improved the quality of survived embryos via increasing the blastocyst hatching.