Jumping in the human brain: A review on somatic transposition.

As a Nobel Prize-winning discovery, transposable elements, or "jumping genes", have attracted significant interest due to their roles in providing functional coding and regulatory sequences. A longstanding hypothesis suggests that somatic transposition may preferentially occur in the mammalian brain, contributing to neuronal diversity. Here, we aim to provide the latest overview of somatic transposition studies in the human brain. We first introduce the historical context and the limited studies on the functionality of somatic transposition, indicating its pathogenic role. We then highlight the wide variability in somatic transposition rate estimates across studies, discussing the complexities-such as artificial chimeras and the multicopy nature-that contribute to false positive and negative results. We also review the evolving experimental and computational methods designed to mitigate these challenges and briefly cover studies estimating germline transposition rate. Finally, we suggest that advances in single-cell genome amplification methods, coupled with deep learning-based software, could pave the way for more definitive studies on the prevalence and functional role of somatic transposition in the human brain.