title: Repression of nucleolar organizer activity in an interspecific hybrid of the genus Xenopus.
mesh_terms: D000818:Animals; D001001:Anura; D002466:Cell Nucleolus / Q000502:physiology*; D003433:Crosses, Genetic; D004625:Embryo, Nonmammalian / Q000648:ultrastructure; D006824:Hybridization, Genetic; D007814:Larva / Q000648:ultrastructure; D008675:Metamorphosis, Biological; D010641:Phenotype; D014981:Xenopus