Phylogenetic relatedness rather than aquatic habitat fosters horizontal transfer of transposable elements in animals
Year: 2025
Type: preprint
Abstract: Horizontal transfer of transposable elements (HTT) is an important driver of genome evolution, yet the factors conditioning this phenomenon remain poorly characterized. Here, we screened 247 animal genomes from four phyla (annelids, arthropods, mollusks, chordates), spanning 19 independent transitions between aquatic and terrestrial lifestyles, to evaluate the suspected positive effects of aquatic habitat and of phylogenetic relatedness on HTT. Among the 5,952 independent HTT events recovered, the vast majority (>85%) involve DNA transposons, of which Mariner-like and hAT-like elements have the highest rates of horizontal transfer, and of intra-genomic amplification. Using a novel approach that circumvents putative biases linked to phylogenetic inertia and taxon sampling, we found that HTT rates positively correlate with similarity in habitat type but were not significantly higher in aquatic than in terrestrial animals. However, modelling the number of HTT events as a function of divergence time in a Bayesian framework revealed a clear positive effect of phylogenetic relatedness on HTT rates in most of the animal species studied (162 out of 247). The effect is very pronounced: a typical species is expected to show 10 times more transfers with a species it diverged from 125 million years (My) ago than with a species it diverged from 375 My ago. Overall, our study underscores the pervasiveness of HTT throughout animals and the impact of evolutionary relatedness on its dynamics. Significance statement Genetic material can be transmitted between organisms through other means than reproduction, in a process called horizontal transfer. The mechanisms and factors underlying this phenomenon in animals remain unclear, although it often involves transposable elements (TEs). TEs are DNA segments capable of jumping within genomes, but also occasionally between individuals. Here, we show evidence for nearly 6,000 transfers of TEs among animals, based on genomic comparisons among 247 species of annelids, arthropods, chordates and mollusks. Contrarily to expectations, we found no excess in the rates of transfers in aquatic versus terrestrial animals. By contrast, most analyzed species appeared engaged in many more horizontal transfers with close than with distant relatives, highlighting the strong impact of phylogenetic relatedness on horizontal transfers of TEs.
Source: Genome Research
Institutions: Centre National de la Recherche Scientifique, State University of New York, Université Paris-Saclay, University at Albany, State University of New York, Évolution, Génomes, Comportement, Écologie, Institut de Recherche pour le Développement, Université de Poitiers, Écologie et Biologie des Interactions, Lyon 1 Université, Université de Lyon, Laboratoire de Biométrie et Biologie Evolutive, Processus Infectieux en Milieu Insulaire Tropical
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: green
Awards: Assessing the contribution of viruses to horizontal DNA transfer, Horizontal transfers of transposable elements: What makes genome invasions successful?, Mutualised Digital Spaces for FAIR data in Life and Health Science, Institut français de bioinformatique, Patterns and processes of horizontal DNA transfer: an in-depth exploration of the host-parasitoid route
OpenAlex ID: W4413055278