A combination of functional, biochemical and imaging studies show that LINE-1/L1 proteins and mRNA enter the nucleus through mitotic nuclear membrane breakdown, interact with components of the DNA replication fork and mediate retrotransposition during S phase.

Human LINE-1 retrotransposition is found to critically depend on the rapidly evolving N-terminal sequence of the LINE-1 ORF1 protein and on the metastability of its coiled coil domain, indicating uncharacterized steps in LINE-1 retrotransposition.

The range of molecular forms adopted by L1 retrotransposons reflect a tapestry of lifecycle-permissive and -restrictive host-parasite interactions occurring within cells.

Combining in vitro and in vivo assays demonstrates that the cytidine deaminase APOBEC3A can inhibit LINE-1 retrotransposition by deaminating transiently exposed single-strand DNA that arises during the process of LINE-1 integration.

The LINE-1 retrotransposon protein, ORF1p, forms a condensate on RNA that is essential for retrotransposition, and may explain cis-preference through a co-translational assembly mechanism.

Post-translational regulation of retrotransposons plays a key role in preventing retrotransposon mobilization in the epigenetically dynamic mouse germline.

A new experimental system of horizontal gene transfer demonstrates that host retrotransposons facilitate the transfer of host genes into poxviruses.

DNA hypomethylation in human tumor cells results in the activation of the LINE-1-derived RNA-binding protein L1TD1 and its interactions with LINE-1 transposons.

The expression of human L1 retrotransposons is highly locus-specific and variable between different cell types.

Active selfish genetic elements in infected cells aid virus adaptation by catalyzing the transfer of host genes to virus genomes.