Preprint: removing the germline reprogrammes somatic DNA repair towards higher fidelity in zebrafish

A preprint posted to bioRxiv by researchers using zebrafish (Danio rerio) reports that eliminating the germline — by CRISPR/Cas9-mediated knockout of the germline determinant gene dnd-1 — reshapes DNA repair and genotoxic stress-response programmes across multiple somatic organs.

Using multi-organ transcriptomics, the authors compared germline-free (GLF) males and germline-carrying (GLC) siblings across five somatic tissues at baseline and after sub-lethal gamma-irradiation. GLF animals showed upregulation of high-fidelity DNA repair pathways and a shift towards more energy-efficient repair strategies relative to GLC controls, suggesting that the soma actively reconfigures its genome-maintenance priorities in the absence of a germline.

The findings contribute to a longstanding conceptual question in evolutionary biology: whether the soma is, in effect, disposable relative to the germline, and whether germ cells exert systemic signalling influence on somatic genome integrity. This work provides transcriptomic evidence that such cross-tissue communication exists at the level of DNA repair gene regulation in a vertebrate model.

The preprint has not yet been peer-reviewed. It is primarily of interest to researchers working in genome stability, ageing biology, reproductive genetics, and evolutionary biology, as well as educators and students engaged with the soma-germline distinction.