Background: The ability to eliminate a parental genome from a eukaryotic germ cell
is a phenomenon observed mostly in hybrid organisms displaying an alternative propagation
to sexual reproduction. For most taxa, the underlying cellular pathways and timing
of the elimination process is only poorly understood. In the water frog hybrid Pelophylax
esculentus (parental taxa are P. ridibundus and P. lessonae) the only described mechanism
assumes that one parental genome is excluded from the germline during metamorphosis
and prior to meiosis, while only second genome enters meiosis after endoreduplication.
Our study of hybrids from a P. ridibundus-P. esculentus-male populations known for
its production of more types of gametes shows that hybridogenetic mechanism of genome
elimination is not uniform.