The organism has a genetic system capable of eliminating the introduced foreign genome at the level of individual. Examples are known with the elimination of a alien genome in the case of hybridogenesis in tailless amphibians (sem, Ranidae). In natural hybrids, originating from two different species of frogs, during the gametogenesis, the genome of one of the original species is eliminated and, as a result, spermatozoa or oocytes containing one of the remaining genomes are produced. Hybridogenesis in frogs was discovered in 1968 (Berger, 1968), however, the molecular mechanisms of recognition of the non-specific genome with its subsequent elimination have not been established. This is the essence of the problem that has not been solved so far. The presented project of the Japanese and Russian research groups consists in a joint search for approaches to understanding the molecular mechanisms of hybridogenesis, where for the first time Russian green frogs Pelophylax ridibundus and P. lessonae and Japanese brown frogs Rana tsushimensis and R. japonica, in which the elimination of the foreign genome in allotriploid forms. The work will combine analysis of the structure of natural populations — determining the species composition and ploidy by studying chromosomes and cell sizes with the technique of studying ovulation and spermatogenesis under artificial conditions. During the implementation of the project, modern molecular genetic technologies will be used: identification of piRNA and target transposed elements and comparative analysis of the RNA sequence of the next generation of germ cells of hybrid and non-hybrid species. By identifying chromosomes and identifying differences in DNA methylation, the exact moment of chromosome elimination will be determined and the dynamics of the process evaluated. It is expected that as a result of the project, not only the molecular mechanisms characteristic of the studied representatives of this family will be revealed. Ranidae, but the hypothesis of the universality of the genome elimination phenomenon associated with the mechanism of reproductive isolation, which is crucial for the conservation and reproduction of species, will also be confirmed.
The presented project is aimed at revealing the general molecular mechanisms characteristic of both related and distant species and confirming that elimination of the genome is not an exceptional but universal phenomenon in organisms. Apparently, genome elimination plays an important role in the mechanisms of reproductive interspecific isolation and evolution.