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Updated: Dec 6, 2025
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Isolation of Giant Lampbrush Chromosomes from Living Oocytes of Frogs and Salamanders
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Phylotranscriptomic evidence for pervasive ancient hybridization among Old World salamanders
Loïs Rancilhac1, Iker Irisarri2, Claudio Angelini3
1Zoological Institute, Technische Universität Braunschweig, Mendelssohnstr. 4, 38106 Braunschweig, Germany.
Molecular Phylogenetics and Evolution
|October 8, 2020
Summary
Hybridization events in salamanders have shaped their evolution, causing discordance between mitochondrial and nuclear DNA trees. This study reveals introgression within newt lineages, suggesting complex evolutionary histories beyond simple branching.
Area of Science:
- Evolutionary Biology
- Genomics
- Phylogenetics
Background:
- Hybridization leaves genetic traces that can complicate evolutionary tree reconstructions.
- Previous studies on Salamandridae (salamanders) show conflicting phylogenetic relationships between mitochondrial and nuclear DNA.
- Understanding these discordances is crucial for accurate evolutionary history of the family.
Purpose of the Study:
- To resolve the phylogeny of the Salamandridae family using a phylotranscriptomic approach.
- To investigate and identify instances of inter-lineage introgression within the family.
- To understand the causes of mito-nuclear phylogenetic discordance.
Main Methods:
- Generated new transcriptomic (RNAseq) data for 20 salamandrids.
- Combined new data with published mitochondrial genomes (28) and transcriptomic data.
- Utilized concatenation and species-tree phylogenetic methods, alongside introgression tests and phylogenetic networks.
Main Results:
- Established a robust phylogeny for Salamandridae, resolving relationships among genera.
- Identified evidence of gene flow (introgression) within 'Modern Asian Newts' and 'Modern European Newts' clades.
- Observed significant mito-nuclear phylogenetic discordances, suggesting hybridization and mitochondrial capture events.
Conclusions:
- Hypothesize specific scenarios of hybridization and mitochondrial capture involving Lissotriton, Ichthyosaura, Triturus, and Calotriton.
- Suggest that introgression events, including nuclear gene flow, occurred within the Cynops lineages.
- Emphasize the need for more comprehensive genomic data to fully elucidate complex hybridization histories in newts.
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