Meena Yadav, Pranav Buch, Isha Desai and Suresh Balakrishnan
A number of growth factors are known to play indispensible roles in the process of tail regeneration in lizard. However, studies on the role of Epidermal Growth Factor (EGF) are few. The current study was aimed at specifically studying the effect of exogenous administration of EGF on the proliferative and synthetic activities of cells in the regenerating tail of adult wall lizard Hemidactylus flaviviridis. The lizard restores an amputated tail through three major stages of growth, viz., Wound Epithelium, Blastema and Growth and Differentiation. These stages, particularly the blastema stage, involve large scale proliferation of cells, which is naturally accompanied by extensive DNA replication and protein synthetic activities. We have used biochemical estimations and histofluorescence analysis to show that externally applied EGF enhances the process of early growth and repair in an amputated tail. The synthesis of nucleic acids and proteins was also found significantly elevated. These results suggest a definite role of EGF as a protagonist of healing and proliferation of an amputated tail in adult wall lizard. Further studies identifying the cellular events which are being regulated by the timed expression of EGF are required to draw a better understanding of the mechanism underlying epimorphic regeneration.
