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Ultrastructure of poison glands of South American frogs: A comparison between Physalaemus albonotatus and Leptodactylus chaquensis (Anura: Leptodactylidae)
Author(s) -
Alvarez Blanca Beatriz,
Delfino Giovanni,
Nosi Daniele,
Terreni Alessandro
Publication year - 2005
Publication title -
journal of morphology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 74
eISSN - 1097-4687
pISSN - 0362-2525
DOI - 10.1002/jmor.10301
Subject(s) - ultrastructure , biology , myoepithelial cell , leptodactylidae , anatomy , endoplasmic reticulum , serous fluid , golgi apparatus , microbiology and biotechnology , zoology , immunohistochemistry , biochemistry , immunology
Serous (poison) cutaneous glands of the leptodactylid species Physalaemus albonotatus and Leptodactylus chaquensis were compared using light and transmission electron microscopy. Glands in the two species share structural traits common in anurans, including the peripheral contractile sheath (myoepithelium) and the syncytial secretory unit that produces, stores, and modifies the poison. At the ultrastructural level, early steps of poison production are also similar and fit the usual path of proteosynthesis, involving rough endoplasmic reticulum (RER) and Golgi stacks (dictyosomes) in the peripheral syncytial cytoplasm. However, several differences are obvious during the maturational processes that lead post‐Golgian products to their ultimate ultrastructural traits. In P. albonotatus , the dense product released from the dictyosomes acquires a thick repeating substructure, which, however, becomes looser in the inner portion of the syncytium. In L. chaquensis , serous maturation involves gradual condensation, and opaque, somewhat “vacuolized” granules are formed. These different maturational paths expressed during poison manufacturing in the two species agree with the polyphyletic origin of the family Leptodactylidae. On the other hand, data collected for P. albonotatus fit previous findings from P. biligonigerus and stress the view that poisons produced by congeneric species share similar (or identical) ultrastructural features. © 2004 Wiley‐Liss, Inc.