Protein expression control by targeted elimination of ovomucoid in chicken eggs

Ovomucoid is a major allergen in chicken egg whites and is characterized by exceptional structural stability conferred by multiple disulfide bonds and glycosylation, rendering it highly resistant to thermal processing and gastrointestinal digestion. These properties fundamentally limit conventional food-processing-based approaches for allergen reduction. From the perspective of controlling protein expression, eliminating ovomucoids at the biosynthetic level represents a rational alternative strategy. This review has summarized the molecular and structural features of ovomucoid that underlie its allergenicity and resistance to processing, and outlines the limitations of traditional allergen reduction methods. Recent advances in targeted gene knockout approaches that enable the precise elimination of ovomucoid expression in chicken eggs have been described, with particular emphasis on nuclease-based genome editing technologies. Experimental evidence demonstrating the absence of mature ovomucoid protein, the preservation of egg white functional properties, and the maintenance of bacteriostatic activity is discussed. Key considerations for the safety evaluation and practical implementation of ovomucoid-deficient eggs are also addressed, with reference to other genome-edited foods that have reached practical use. These studies have demonstrated that the functional modification of complex food matrices can be achieved by targeting and inhibiting a single protein, and ovomucoid-deficient chicken eggs are noteworthy as a representative example of the control of animal protein expression.