Mezzherin S.V., Pavlenko L.I.

The case of hybridization in spined loach (Osteichthies : Cobitidae : Сobitis) that stimulated genetical instability and expansion

TSitologiia i genetika 2007, v 41, Issue 4, 26-35

Monitoring of hybrid assemblage of spined loach carried out during the six-year period represents description of the unique case of reproductive interaction of the Danube triploid females C. 2 elongatoides – «tanaitica», spontaneously introduced in the Irpen river (Medium Dnieper river basin), with local diploid males C. taenia. As it appears from the obtained results, even during the similar «crosses» the restricted incorporation of С. taenia genetic material into C. 2 elongatoides-«tanaitica» hybrid genome takes place. As a result the descendants undergo modifications of electrophoretic hybrid spectrum of Aat-1 locus that can be interpreted as development of genetic instability. During two years the generically modified brood has not only completely superseded the normal Danube triploid descendants from the Irpen river, but also has sharply increased representation of introgressants in the basin. As a consequence the assemblage of spined loach of this river at the moment by more than one half consists of the Danube modified triploids. During subsequent gynogenetic «crosses» of already modified triploid female C. 2 elongatoides –«tanaitica» with С. taenia males tetraploid recombinants and backcrosses have appeared in the population which have never been observed in the Dnieper spined loach populations. The fact of the directional genome transformations during gynogenetic crosses proves that initialisation of an ovule splitting by spermatozoon is not generically neutral event.

Mezzherin S.V., Pavlenko L.I. The case of hybridization in spined loach (Osteichthies : Cobitidae : Сobitis) that stimulated genetical instability and expansion // Tsitol Genet. – 2007. – 41(4). – P. 26-35.