Meeting Abstract

P2.60  Wednesday, Jan. 5  Nitric oxide is involved in metamorphic process in anuran tadpoles, Xenopus laevis JOHNSON, JENNIFER; GARDNER, EILEEN; MENON, JAISHRI*; William Paterson University, New Jersey; William Paterson University, New Jersey; William Paterson University, New Jersey menonj@wpunj.edu

In order to adapt to a different habitat, amphibian skin undergoes morphological, biochemical and physiological changes and the tail completely regresses during metamorphosis. Body epidermis remains non-keratinized throughout the larval life and consists of apical cells, skein cells, and basal cells which are the stem cells. Larval cells disappear by apoptosis; the adult stem cells differentiate into adult cornified epidermis. Signaling mediated by nitric oxide (NO) can contribute to stress-related responses where these molecules can act as regulators of metamorphic transitions. NO also has profound effect on the mitochondrial function and recently it has been also reported that mitochondria possess their own nitric oxide synthase (NOS) enzyme. We have carried out double immunostaining with NO-sensitive fluorescent dye DAF-2 and rhodamine 123 to localize mitochondria, alongwith immunohistochemistry for NOS isoforms in skin and tail during metamorphosis of these tadpoles. Our results show co-localization for NO and mitochondria in both the organs. However, in body epidermis only neuronal NOS (NOS I) is present in skein and basal cells, whereas apical cells are devoid of any enzyme activity. In tail, both NOS I and II are found to be present before the beginning of tail regression. These findings are discussed in terms of putative functional importance of mitochondrial derived NO and differential isoform expression in body skin morphogenesis and apoptosis in tail tissue.