Abstract: The present invention provides nucleic acid sequences coding Cyn d I, or at least one fragment thereof or the functional equivalent of such nucleic acid sequences. The present invention also provides expression vectors comprising such nucleic acid sequences and host cells transformed therewith. The present invention further provides isolated Bermuda grass pollen protein allergen Cyn d I or fragments thereof. Isolated Bermuda grass pollen protein allergens or antigenic or allergenic fragments thereof are useful for diagnosing and treating sensitivity in an individual to Bermuda grass pollen allergens.