Entries on Genetic Engineering
Tails of three groups of the Gekkonid lizard, Hemidactylus flavivirdis, were amputated (group I) orautotomized (groups II and III). The animals were exposed to 12 hours of ight and 12 hours of darkness. Ingroup I experiment, previously regenerated tails were amputated (repeated autotomyRA) with a pair of sharp scissors, after anesthetizing the animals with ice cubes, at point equivalent to three autotomy segments. The orginal planes of autotomy have been replaced by ependymal tubes and there were noblood exudates,. In group II the spinal cord at thelocal site of autotomy was carefuly removed (spinal cord removed, SCR), with dissecting instruments, for a length equal to one autotomy segment Lizards in group III served as controls (NormalLizard NL). The results show that the initiation o regeneration, the growth rate, the total length of new growth (regenerate) produced, and the total percentage replacement of the lost (amputated/autotomized) tails 30 days after excision were all signiicantly less in lizards of group II (p < 001) and insignifcantly less in group I lzards, when compared with the controls (group III). The results show that for complete regeneration of the lizard tai neural tissue must be present.