Park, S.C.*; Cho, S.J.; Lee, M.S.; Cho, P.Y.; Koh, K. S.: Developmental Changes of Blastema and Proteinase Activities during Earthworm Tail Regeneration

Developmental Changes of Blastema and Proteinase Activities during Earthworm Tail Regeneration Sung Jin Cho, Myung Sik Lee, Pyo Hyun Cho and Soon Cheol Park Department of Life Science, Chung-Ang University, Seoul 156-756, Korea Although the earthworm is an important animal species capable of regenerating missing body part, earthworm regeneration is not well understood at the tissue, cell and molecular levels. In order to understand the developmental changes of blastema and the significance of proteinase activity during earthworm tail regeneration, the formation and development of blastema and the characteristics of proteinases induced during regeneration were investigated by histological and zymographic analysis. By histological observation, we have identified that a major origin of earthworm blastemal cells is the longitudinal muscle layer of body wall. Blastema formed beneath wound dermis was segmented and then redifferentiated. Zymographic analysis of proteinase revealed that at least four types of proteinases were induced during tail regeneration, which had molecular weight of 25, 28, 38, and 44 kDa, respectively. Proteinase activities were begun to increase within 24 hrs after amputation. All types of proteinase activities induced during tail regeneration were strongly inhibited by treatment of PMSF and aprotinin but not by pepstatin A, E-64, iodoacetamide and metal ion free-medium, indicating that they are serine proteinases. By fibrin autography, we have detected an elevation of plasminogen activator (PA) just prior to serine proteinase peaks, suggesting that these serine proteinases would be a member of plasmin.