Acid Phosphatase and Vitamin A Induced Abnormal Tail Regeneration in Frog Tadpoles: an Immunohistochemical Study

Abstract

Application of vitamin A palmitate or retinoic acid causes abnormal tail regeneration and sometimes leads to formation of ectopic hind limbs along with pelvic girdles at the cut end of tail. Such a phenomenon referred to as homeotic transformation, has been reported in different anuran species. Acid phosphatase, a lysosomal marker enzyme is known to be associated with regeneration in amphibians. However, role of this enzyme during homeotic transformation of tail of an anuran tadpole into limbs is not explored. Thus, aim of the present study is immunohistochemical localization of acid phosphatase in non-amputated, normally regenerated and vitamin A treated abnormally regenerated tails (a prerequisite for ectopic organ development) of tadpoles of the Indian tree frog Polypedates maculatus. In the non-amputated and normally regenerated tails, acid phosphatase is majorly restricted to the epidermis and muscle patches although in the normally regenerated tails notochordal sheath and spinal cord also stain for acid phosphatase. In vitamin A treated tails, acid phosphatase is mostly localized in the epidermis, notochord precursor cells and undifferentiated cells of the mesenchyme. Notochordal cells and notochordal sheath also show positive staining. Since, acid phosphatase is majorly expressed by tissue forming precursor cells, this enzyme is suggested to be involved in tissue remodelling processes.