Transglutaminase Activity Is Conserved in Stratified Epithelia and Skin Appendages of Mammals and Birds

This study reveals that transglutaminase (TGM) activity is conserved across various stratified epithelia and skin appendages in mammals and birds, playing a crucial role in the cornification process. TGM activity was detected in human tissues such as the epidermis, gingiva, nail matrix, and sweat gland ducts, as well as in the claw matrix and feather structures of chickens. The findings suggest that TGM-mediated protein cross-linking is essential for the structural integrity and mechanical stability of these tissues, highlighting its evolutionary significance in the formation of hard skin appendages like nails and feathers.