Evolutionary conservative chemosignal 2,5-dimethylpyrazin that is pheromone in female mice has been shown to increase frequency of mitotic aberrations analyzed with aid of metaphasic and ana-telophasic analysis in bone marrow cells. Replacement of one of methyl radicals in the pheromone molecule by the carboxyl radical reveals specificity of action of the used derivative: the frequency of disturbances revealed only by the ana-telophasic analysis increases, whereas by the metaphasic analysis, no induction of disturbance is detected. In the sperm head abnormality test there is shown a rise of the anomalies by both compounds. Possible mechanisms of specific action of the tested substances on stability of genetic apparatus of the bone marrow dividing cells in the house mouse are discussed.