Abstract
Organ regeneration (epimorphosis) differs from development in that morphogenesis occurs in a restricted region neighboring normal tissues. However, the molecular mechanisms specific to epimorphosis are unknown. Previously, we reported that regenectin, a humoral lectin from the American cockroach Periplaneta americana, appears transiently during leg regeneration and is localized around regenerating muscle cells [Kubo, T. et al. (1991) Int. J. Dev. Biol. 35, 83-90]. We recently isolated a cDNA for regenectin and examined the expression of the gene. We found that the gene was activated in the epidermis of the regenerating leg but not during the normal developmental stages. These results suggest that regenectin is specifically synthesized and secreted by the regenerating epidermis and that it plays a role in the formation of muscle in a paracrine manner.
Analysis of the primary structure of regenectin revealed that regenectin belongs to the same family as LPS-binding protein, which was purified previously from Periplaneta hemolymph and which participates in the defense system. This implies that epimorphosis and the defense system share some common molecular aspects. In this minireview, we describe recent research on cockroach humoral lectins and discuss molecular mechanisms specific to epimorphosis.
