Double-stranded DNA viruses may serve as vectors for horizontal transfer of intron-generating transposons

Specialized transposable elements capable of generating introns, termed introners, are one of the major drivers of intron gain in eukaryotes. Horizontal gene transfer (HGT) is thought to play an important role in shaping introner distributions. Viruses could function as vehicles of introner HGT since they often integrate into host genomes and have been implicated in widespread HGT in eukaryotes. We annotated integrated viral elements in diverse dinoflagellate genomes with active introners and queried viral elements for introner sequences. We find that 25% of viral elements contain introners. The vast majority of viral elements represent maverick-polinton-like double-stranded DNA (dsDNA) viruses as well as giant dsDNA viruses. By querying a previously annotated set of maverick-polinton-like proviruses, we show that introners populate full-length elements with machinery required for transposition as well as viral infection. Introners in the vast majority of viral elements are younger than or similar in age to others in their host genome, suggesting that most viral elements acquired introners after integration. However, a subset of viral elements show the opposite pattern wherein viral introners are significantly older than other introners, possibly consistent with virus-to-host horizontal transfer. Together, our results suggest that dsDNA viruses may serve as vectors for HGT of introners between individuals and species, resulting in the introduction of intron-generating transposons to new lineages. ### Competing Interest Statement R.C.-D. was supported by R35GM128932.

Double trouble: two retrotransposons triggered a cascade of invasions in Drosophila species within the last 50 years - Nature Communications

Horizontal transfer of genetic material in eukaryotes has rarely been documented over short evolutionary timescales. Here, the authors show that two transposable elements, Shellder and Spoink, invaded the genomes of multiple Drosophila species within the last 50 years.

Comprehensive analysis reveals hidden genomic evolution of brown algae

Covering over 70% of Earth's surface, the oceans are home to countless life forms that maintain ecological balance and support human well-being. Among these, brown algae (Phaeophyceae) play a crucial role in sustaining coastal habitats, supporting marine biodiversity, and combating climate change through carbon capture. While they have long captured the interest of the scientific world, the genomic and evolutionary history of these organisms has remained largely unexplored.

Small animals acquire genes from bacteria that can produce antibiotics

A group of small, freshwater animals (bdelloid rotifers) protect themselves from infections using antibiotic recipes “stolen” from bacteria, according to new research by a team from the University of Oxford, the University of Stirling and the Marine Biological Laboratory, Woods Hole. This raises the potential that rotifers are producing novel antimicrobials that may be less toxic to animals, including humans, than those we develop from bacteria and fungi.

BugBitten Horizontal gene transfer explains the origin of parasite molecules that manipulate host behaviour.

Philippines research offers hope for conserving enigmatic Rafflesia plants

Found only in Southeast Asian rainforests, the Rafflesia genus produces the world’s largest flowers. Their prodigious size is no small feat, considering that Rafflesia possess neither roots, leaves nor stems. They are also incapable of photosynthesis, relying entirely on their hosts (certain species of Tetrastigma vines) for nourishment. These parasitic plants remain one of botany’s […]

Superbug: An Epidemic Begins

As antibiotic resistance spreads, scientists and doctors race time.

Evidence found of possible interdomain horizontal gene transfer leading to development of the eye in vertebrates

A group of molecular and chemical biologists at the University of California, San Diego, has found possible evidence of interdomain horizontal gene transfer leading to the development of the eye in vertebrates. In their study, reported in Proceedings of the National Academy of Sciences, Chinmay Kalluraya, Alexander Weitzel, Brian Tsu and Matthew Daugherty used the IQ-TREE software program to trace the evolutionary history of genes associated with vision.

Genes on the move: Mapping the pathways of horizontal gene transfer

In the past few decades, there has been a rise in antibiotic-resistant infections, which are becoming an increasingly urgent public health concern. According to the World Health Organization, at least 700,000 people die each year due to antibiotic-resistant infections, and this number is only expected to increase as more and more bacteria become resistant to commonly used antibiotics.