Familial goiter in bongo antelope (Tragelaphus eurycerus)

Congenital defects in thyroglobulin (T_g) synthesis in animals have proven to be useful models for the study of T_gsynthesis and regulation. Defects in T_gsynthesis have been well described in Afrikander cattle, Australian Merino sheep, and goats in The Netherlands. This report describes a study of goiter in a nondomesticated bovine species, bongo antelope (Tragelaphus eurycerus), an African bovid. Three animals housed at the National Zoological Park, Washington, D.C. were studied; two had visible goiters, and a third bongo had microscopic evidence of goiter. T_gextracted from thyroid glands or thyroid colloid from these animals had a high mol wt component that was greater than 220K daltons and differed in apparent mol wt from 19S T_gfrom domestic cattle. Thyroid extracts also had thyroid albumin; albumin was more than half the total protein in colloid extract. The animals with goiter were euthyroid according to their circulating levels of thyroid hormones.