Research scientists at Hiroshima University have developed chicken eggs that they claim “may be safe for people with egg white allergies”.

The scientists have produced an egg called the ‘OVM-Knockout’, which they have said does not include ovomucoid, the protein that causes allergies to egg whites. 

According to the university, researchers developed the eggs using genome-editing technology.

“To use OVM-knockout chicken eggs as food, it is important to evaluate its safety as food,” Assistant Prof. Ryo Ezaki from the Graduate School of Integrated Sciences for Life at Hiroshima University in Hiroshima, Japan, said.

“In this study, we examined the presence or absence of mutant protein expression, vector sequence insertion, and off-target effects in chickens knocked out with OVM by platinum transcription activator-like effector nucleases (TALENs).”

To develop the modified eggs, researchers needed to detect and eliminate the ovomucoid protein in the egg whites.

TALENs were utilised to target a piece of RNA called exon 1, which codes for specific proteins.

The eggs produced from this technique were then tested to ensure there were no ovomucoid protein, mutant ovomucoid protein, or other off-target effects.

Allergen-free eggs

“The eggs laid by homozygous OVM-knockout hens showed no evident abnormalities. The albumen contained neither the mature OVM nor the OVM-truncated variant,” Ezaki said.

He also explained that the potential TALEN-induced off-target effects in OVM-knockout chickens were localised in the intergenic and intron regions.

According to researchers, the plasmid vectors used for genome editing were only transiently present and did not integrate into the genome of edited chickens.

Assistant Prof. Ezaki said that these results indicated the importance of safety evaluations and revealed that the eggs laid by this OVM knockout chicken solved the allergy problem in food and vaccines.

Safety profile

Researchers have confirmed that they plan to continue to verify the safety profile of the modified eggs.

They said that this is important as some people are highly allergic to specific protein which means that even small amounts of ovomucoid could cause a reaction.

Currently, researchers have determined that the OVM-knockout eggs are “less allergenic than standard eggs and can be safely used in heat-processed foods that patients with egg allergies can eat”.

Assistant Prof. Ezaki said: “The next phase of research will be to evaluate the physical properties and processing suitability of OVM-knockout eggs, and to confirm their efficacy through clinical trials.

“We will continue to conduct further research toward the practical application of allergy reduced eggs.”