DENERVATION AND CONCOMITANT AMPUTATION OF ADVANCED FORELIMB REGENERATIVE OUTGROWTHS IN ADULT XENOPUS-LAEVIS

The current investigation was undertaken to determine whether year-old regenerative outgrowths of adult Xenopus laevis respond to forelimb d enervation and concomitant amputation through the distal one-third of the regenerate in the same manner as younger regenerates of postmetamo rphic X. laevis froglets. Following limb amputation, our innervated an d sham-denervated adult frogs regenerated typical spike-like outgrowth s by 63 weeks. However, denervation of 60-week-old regenerates and den ervation concomitant with amputation through the regenerative outgrowt hs of the mature frogs in series III and VI, respectively, resulted in no significant regression (resorption) or further growth of the regen erates 3 weeks later. Therefore, 60-week-old experimental regenerates can be considered mature appendages, as they maintained morphological stability for an additional 3 weeks in the absence of innervation. Our results are in contrast with the regression of regenerate tissues pre viously reported in delayed-denervated younger forelimb regenerates, a s well as concomitantly denervated and amputated regenerates of X. lae vis froglets.