Premeiotic chromosome doubling after genome elimination during spermatogenesis of the species hybrid Rana esculenta.

Gamete production in the hybridogenetic species hybrid Rana esculenta (Rana ridibunda X Rana lessonae) is preceded by a premeiotic elimination of the R. lessonae genome and subsequent duplication of the remaining R. ridibunda genome, so that only ridibunda chromosomes enter a quasi normal meiosis, and only ridibunda gametes are formed. This is demonstrated by differences in genome specific centromere fluorescence and electrophoretic patterns between somatic and gonadal tissue.