Hominoid-specific retrotransposons fuel regulatory novelty in early brain development.

Transposable elements can drive genetic innovation. In this issue of Cell Genomics, Adami et al.1 investigate the impact of hominoid-specific L1 retrotransposons on early embryonic and brain development. Using induced pluripotent stem cells and cerebral organoid models, multi-omics, and CRISPRi-mediated silencing, they uncover a cis-regulatory role for these young retrotransposons in early human brain development.