2025/08/20 by Matthew Beaumont, Divya Selvaraju, Riccardo Pianezza +1 · 1 voice · 1 citation
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · #Advanced biosensing and bioanalysis techniques #Biology #CRISPR and Genetic Engineering #Chromosomal and Genetic Variations #Demography #Drosophila melanogaster #Evolutionary biology #Extinction (optical mineralogy) #Gene #Genetics #Genome #Horizontal gene transfer #Host (biology) #Melanogaster #Paleontology #Piwi-interacting RNA #Population #Transposable element
paper · pdf · doi:10.1371/journal.pgen.1011649
openalex publication_date 2025/08/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Transposable element (TE) invasions pose risks to both the TE and the host. All copies of a TE may be lost via genetic drift, or host populations may suffer fitness declines, potentially leading to extinction. By monitoring invasions of the P-element in experimental D. melanogaster populations for over 100 generations, we uncovered a novel risk for invading TEs. In two replicate populations, the P-element rapidly multiplied until a piRNA-based host defence emerged, leading to the plateauing of TE copy numbers. However, in one population (R2), P-element copy numbers stabilised at a significantly lower level, despite the absence of a piRNA-based host defence. We find that this stabilisation was likely driven by the propagation of non-autonomous insertions, characterised by internal-deletions, which out-competed the autonomous full-length insertions. Such a rapid proliferation of non-autonomous insertions could account for the high prevalence of P-element insertions with internal-deletions observed in natural D. melanogaster populations. Our work reveals that TEs may stochastically sabotage their own spread in populations due to the emergence of non-autonomous elements, rendering the establishment of a host defence unnecessary. The proliferation of non-autonomous elements may also lead into an evolutionary dead end, where affected populations are resistant to re-invasion (e.g. following recurrent horizontal transfer), yet are unable to infect other species due to a lack of autonomous insertions.