Researchers from the German Primate Center (DPZ), University Medical Center Göttingen, and the Max Planck Institute for Multidisciplinary Sciences have successfully generated the first primate model for a common form of congenital deafness using common marmosets.
The team used CRISPR/Cas9 gene editing to precisely knock out the OTOF gene in fertilized marmoset eggs. This gene is responsible for producing the protein otoferlin, which is essential for transmitting sound signals from the inner ear’s hair cells to the auditory nerve. Defects in OTOF cause hearing loss in humans even when the inner ear structure appears normal.
The resulting genetically modified marmosets developed normally and are healthy, but they are completely deaf from birth — exactly mirroring the condition seen in human patients with OTOF mutations. Deafness was confirmed through electrophysiological hearing tests (similar to EEG) and by the absence of the otoferlin protein in the inner hair cells.
Why It Matters
This is the first non-human primate model that realistically replicates key features of human OTOF-related deafness. It bridges the gap between existing mouse models, cell cultures, and potential human applications. The model will be particularly valuable for testing and optimizing new treatments, such as gene therapies and optogenetic cochlear implants, in a system much closer to human physiology. It also allows researchers to better evaluate the safety, efficacy, and long-term effects of these therapies.
The achievement highlights the power of interdisciplinary collaboration in reproductive biology, genome editing, and neuroscience. Researchers describe it as a major step forward for translational research in hearing disorders.
