Polyploidy and Chromosomal Dynamics in Anuran Amphibians

Polyploidy, the condition of possessing more than two complete sets of chromosomes, has played a pivotal role in the diversification of anuran amphibians. Among pipid frogs, African clawed frogs (genus Xenopus) exemplify repeated whole-genome duplications, yielding diploid, tetraploid, octoploid and dodecaploid lineages. Such events generate genomic redundancy that can facilitate novel gene functions, alter developmental pathways and drive reproductive isolation. Chromosomal dynamics following polyploidy involve structural rearrangements—fusions, fissions, inversions—and shifts in the location and copy number of repetitive elements and nucleolus organiser regions. Over evolutionary time many polyploid genomes undergo diploidization, whereby duplicated chromosomes diverge by sequence loss, epigenetic modification or reorganisation, restoring stable bivalent pairing at meiosis. Comparative cytogenetics across diverse anuran clades reveals both conserved karyotype features and lineage-specific rearrangements that underpin speciation and adaptation to a wide range of aquatic and terrestrial habitats. These systems serve as models for understanding genome evolution, with implications for biodiversity conservation, developmental biology and the mechanisms governing chromosomal stability in vertebrates.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Polyploidy and Chromosomal Dynamics in Anuran Amphibians publication trend

The graph below shows the total number of articles in polyploidy and chromosomal dynamics in anuran amphibians across all publications each year (not limited to Nature Index journals).

Technical terms

Polyploidy: Possession of more than two complete chromosome sets in a cell.

Allopolyploidy: Polyploidy arising from hybridisation between distinct species, combining divergent genomes.

Autopolyploidy: Polyploidy arising from duplication within a single species genome without hybridisation.

Fluorescence in situ hybridization (FISH): Cytogenetic technique that uses fluorescent probes to localise specific DNA sequences on chromosomes.

Nucleolus organiser region (NOR): Chromosomal region containing ribosomal RNA gene clusters that form the nucleolus during interphase.

Diploidization: Evolutionary process by which a polyploid genome regains diploid-like behaviour through structural and functional divergence of duplicated chromosomes.

References

1. FISH mapping in Xenopus pygmaeus refines understanding of genomic rearrangements and reveals jumping NORs in African clawed frogs. Heredity (2025).
2. Consequences of polyploidy and divergence as revealed by cytogenetic mapping of tandem repeats in African clawed frogs (Xenopus, Pipidae). European Journal of Wildlife Research (2023).
3. Tetraploidy in the Boettger’s dwarf clawed frog (Pipidae: Hymenochirus boettgeri) from the Congo indicates non-conspecificity with the captive population. Zoological Journal of the Linnean Society (2023).