Development of serous cutaneous glands in Scinax nasica (Anura, Hylidae): patterns of poison biosynthesis and maturation in comparison with larval glands in specimens of other families

Ultrastructure of poison glands of South American frogs: A comparison betweenPhysalaemus albonotatus andLeptodactylus chaquensis (Anura: Leptodactylidae)

“…The remarkable differences between cutaneous poisons in the two genera under comparison agree with the possible non-monophyletic status of the family Leptodactylidae (Ford and Cannatella, 1993). At the generic level, it appears that poison biosynthesis in Physalaemus albonotatus closely resembles that of P. biligonigerus (Delfino et al 1999b(Delfino et al , 2001aTerreni et al, 2003), which, in turn, support the data listed in Table 1. Results obtained from Physalaemus in the present study are even more relevant because we have described identical features in species pertaining to different groups of this genus: the smaller biligonigerus tribe and the larger cuvieri tribe including albonotatus (Cei, 1980).…”

Life history linked to immune investment in developing amphibians

“…Granular glands of amphibian skin may not be able to discharge their AMP products fully onto the skin surface by a holocrine process until after development of the neuromuscular secretory apparatus and gland ducts in the epidermis (Delfino, 1980; Faszewski and Kaltenbach, 1995; Delfino et al ., 1998, 2006; Lacombe et al ., 2000). However, mature gland products may also be secreted by a merocrine process (either constitutive or induced exocytosis) and flow between epidermal cell layers and through epidermal interstices onto the skin surface before complete gland duct development (Delfino et al ., 1998; Terreni et al ., 2003; Quagliata et al ., 2006). Some studies used transmission electron microscopy to examine discharge of granular glands (Delfino et al ., 2006).…”

Serous cutaneous glands in the South American horned frog Ceratophrys ornata (Leptodactylformes, Chthonobatrachia, Ceratophrydae): Ultrastructural expression of poison biosynthesis and maturation

“…On the other hand, serous secretions of some anuran species from different families are similar or identical in structure (Delfino et al, 2001a,b;Terreni et al, 2002Terreni et al, , 2003, reflecting either phylogenetic relationships or convergence. Ultrastructural features of cutaneous poisons are expressed by distinctive biosynthesis as well as maturational programs and may represent genus-specific character systems, informative on the phylogenetic relationships among anurans.…”

“…Serous glands in adult anurans only provide scanty ultrastructural data for our knowledge of Delfino, 1991;Delfino et al, 1992;Terreni et al, 2003 Bracketed numbers (*) identify families as branches of the phylogenetic tree of Frost et al (2006).…”

“…In mature serous glands of dendrobatids, smooth surfaced tubules may form thick aggregations, in the fashion of para-crystalline structures (Neuwirth et al, 1979). In anuran glands producing dense granules (Delfino, 1977;Delfino et al, 1988Delfino et al, , 1993, and granules with repeating substructures (Delfino et al, 1994;Terreni et al, 2003), the developmental change in the biosynthetic apparatus involves variation in the width and orientation of rough endoplasmic reticulum cisterns. Apart from antimicrobial/hemolytic peptides and proteins (Barberio et al, 1987;Zasloff, 1987;Zasloff et al, 1988), resembling perforins in their effects on target plasma membranes (Barra and Simmaco, 1995), literature on anuran poison biochemistry mostly deals with small molecules: oligopeptides, alkaloids, biogenic amines and their derivatives (Daly et al, 1987), such as leptodactyline, a fenylalkylamine found in C. ornata (Cei et al, 1967).…”