Uroporphyrinogen III Cosynthetase Activity in the Fox Squirrel (Sciurus niger)

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Science  01 Oct 1971:
Vol. 174, Issue 4004, pp. 59-60
DOI: 10.1126/science.174.4004.59


The activity of uroporphyrinogen III cosynthetase in hemolyzates and tissue extracts from fox squirrels is much less than in similar preparations from gray squirrels. Low activity of this enzyme explains the production of large amounts of uroporphyrin I by the fox squirrel. Members of this species thus provide a small-animal model for studies of congenital erythropoietic porphyria, a hereditary disease of man and cattle which is associated with a similar partial deficiency of uroporphyrinogen III cosynthetase.