SEASONAL-VARIATIONS IN INTEGUMENTAL GLYCOCONJUGATES OF RANA-RUGOSA

Background: Although environmental conditions can influence the expres sion of glycoconjugates (GCs) in the epidermis and cutaneous gland of amphibians, seasonal features regarding GCs in frogs have rarely been studied. In the present study, we report the seasonal variations of th e integumental GCs in Rana rugosa. Methods: GCs were investigated at t he light microscopic level using conventional and lectin histochemistr y. Results: During the pre-through posthibernating periods, stronger p eriodic acid-Schiff (PAS)-positive GCs were observed in the stratum co rneum and transitional layer of the epidermis. At the same time, alcia n blue and PAS-positive GCs filled the lumen of the mucous gland. The affinity for PNA in the transitional layer, UEA-1 in stratum germinati vum, and SBA in the mucous glands increased significantly during the s ame periods. In addition, new GCs, which are specific for SEA in the s tratum corneum, BSL-1, RCA-1, sWGA, and LCA in some cells of the trans itional layer, were detected. Conclusions: Elevated GCs and a diversit y of lectin affinities may be a result of seasonal adaptations related to hibernation. An affinity for PNA, UEA-1, and SEA in the frog shin may be useful as a marker of seasonal changes. (C) 1997 Wiley-Liss, In c.