Preprint: leech infection leaves DNA methylation signatures in loggerhead sea turtles, potentially across generations

A preprint deposited on bioRxiv by researchers studying loggerhead sea turtles (Caretta caretta) reports that infection with the parasitic leech Ozobranchus margoi — a species known to vector fibropapillomatosis — is associated with detectable variation in DNA methylation across the turtle genome, identified through whole-genome bisulfite sequencing.

The study examined nesting females and assessed whether infection-associated methylation patterns could serve as a molecular biomarker of parasite burden in wild populations, where direct detection of infection is often difficult. The authors also investigated whether these epigenetic signals show evidence of transmission across generations — an observation that, if confirmed, would have implications for understanding how infectious pressure can leave heritable molecular marks in a long-lived, endangered vertebrate.

The loggerhead sea turtle is listed as vulnerable under the IUCN Red List, and fibropapillomatosis driven by chelonid alphaherpesvirus 5 represents a significant conservation concern. Tools to detect cryptic infection non-invasively through epigenomic biomarkers would be of practical interest to conservation genomics programmes.

This work is a preprint and has not yet been peer-reviewed. Findings should be regarded as preliminary.