FISH mapping in Xenopus pygmaeus refines understanding of genomic rearrangements and reveals jumping NORs in African clawed frogs

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00023272%3A_____%2F25%3A10136934" target="_blank" >RIV/00023272:_____/25:10136934 - isvavai.cz</a>

Alternative codes found

RIV/68081766:_____/25:00618045 RIV/00216208:11310/25:10505934

Result on the web

<a href="https://www.nature.com/articles/s41437-025-00749-x" target="_blank" >https://www.nature.com/articles/s41437-025-00749-x</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1038/s41437-025-00749-x" target="_blank" >10.1038/s41437-025-00749-x</a>

Result language

angličtina

Original language name

FISH mapping in Xenopus pygmaeus refines understanding of genomic rearrangements and reveals jumping NORs in African clawed frogs

Original language description

Chromosomal rearrangements are fundamental evolutionary drivers leading to genomic diversification. African clawed frogs (genus Xenopus, subgenera Silurana and Xenopus) represent an allopolyploid model system with conserved chromosome numbers in species with the same ploidy within each subgenus. Two significant interchromosomal rearrangements have been identified: a translocation between chromosomes 9 and 2, found in subgenus Silurana, and a fusion between chromosomes 9 and 10, probably widespread in subgenus Xenopus. Here, we study the allotetraploid Xenopus pygmaeus (subgenus Xenopus) based on in-depth karyotype analysis using chromosome measurements and fluorescent in situ hybridization (FISH). We designed FISH probes for genes associated with translocation and fusion to test for the presence of the two main types of rearrangements. We also examined the locations of 5S and 28S ribosomal tandem repeats, with the former often associated with telomeric regions and the latter with nucleolus organizer regions (NORs). The translocation-associated gene mapping did not detect the translocation in X. pygmaeus, supporting the hypothesis that the translocation is restricted to Silurana, but instead identified a pericentromeric inversion on chromosome 2S. The fusion-associated gene mapping confirmed the fusion of chromosomes 9 and 10, supporting this fusion as an ancestral state in subgenus Xenopus. As expected, the 5S repeats were found predominantly in telomere regions on almost all chromosomes. The nucleolar 28S repeats were localized on chromosome 6S, a position previously found only in the closely related species X. parafraseri, whereas other, phylogenetically more distant species have NORs located on different chromosomes. We therefore hypothesize that a jumping mechanism could explain the relatively frequent changes in the location of NORs during Xenopus evolution.

Czech name

—

Czech description

—

Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10613 - Zoology

Project

<a href="/en/project/EH22_010%2F0002902" target="_blank" >EH22_010/0002902: MSCA Fellowships CZ - Charles University</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2025

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Heredity

ISSN

0018-067X

e-ISSN

—

Volume of the periodical

134

Issue of the periodical within the volume

3-4

Country of publishing house

GB - UNITED KINGDOM

Number of pages

12

Pages from-to

209-220

UT code for WoS article

001435426800001

EID of the result in the Scopus database

999