Bobber: a cervical ataxic mutant in the domestic turkey responsive to sunlight.
Bobber is a genetic disorder in the domestic turkey that is usually expressed between two and four weeks of age. The condition is permanent and is characterized by ventrocaudad bending of the neck accompanied by a lateral pendulumlike motion of the head between the legs. Expressivity of the defect is variable and may be exhibited in some turkeys as a stargazing posture or a rapid clockwise twirling motion. When suspended by the legs in a head-down orientation, afflicted turkeys exhibit an inward turning of the neck and head toward the breast as opposed to an outward turning in normal turkeys. The disorder is inherited as a sex-linked recessive trait. The symbol bo is used for the gene. The defect can be corrected by exposure to intense light in the visible spectrum.