Muscle regeneration in frog tadpoles

Abstract

Muscle regeneration after tail amputation in old and young tadpoles of frogs is studied histologically. The former age group of animals included 6-months old, 70 to 90 mm long tadpoles of Rana clamitans and 6- week old, 23 to 33 mm long, larvae of Rana sylvatica. The young animals included 3-day old, 9 to 15 mm long tadpoles of the latter species. In the young tadpoles, morphologically undifferentiated cells, situated between the muscles and the epidermis in the stump, constitute the major of cells for regeneration of muscles. In the old tapoles of both species, the cellular material for muscle regeneration is derived in the form of free, mononucleate, myoblasts from partial or complete dedifferentiation of the remnants of inured muscle fibres. The histogenesis of muscles in the regenerating tails of all tadpoles irrespective of their age and the level of amputation proceeds through the same stages as in ontogeny.