Ultrastructural patterns of secretory activity in serous cutaneous glands of the Pacific tree-frog Hyla regilla (Anura, Hylidae)

Biosynthesis and maturation processes are described in Hyla regilla serous cutaneous glands, which produce secretory granules provided with a recurrent substructure, consisting of thick aggregations of globular and rod-shaped subunits. Patterns observed fit those detected in the congeneric Italian tree frog H. intermedia and resemble secretory features in larval Scinax nasica and Physalaemus biligonigerus. These findings suggest that serous glands in species of the same genus may produce granules with identical features through identical secretory steps. In addition, genera of the same family or related families, may share early steps of serous biosynthesis.