Skin glands of an aquatic salamander vary in size and distribution and release antimicrobial secretions effective against chytrid fungal pathogens

• Published in: Journal of experimental biology Vol. 221; no. 14; p. jeb183707
• Main Authors: Pereira, Kenzie E, Crother, Brian I, Sever, David M, Fontenot, Jr, Clifford L, Pojman, Sr, John A, Wilburn, Damien B, Woodley, Sarah K
• Format: Journal Article
• Language: English
• Published: England The Company of Biologists Ltd 01.07.2018
• Subjects: Amphibians; Amphiuma tridactylum; Antiinfectives and antibacterials; Antimicrobial peptides; Batrachochytrium dendrobatidis; Bioactive compounds; Biological activity; Chytridiomycosis; Courtship; Exocrine glands; Fungi; High-performance liquid chromatography; Immune response; Innate immunity; Liquid chromatography; Pathogens; Peptides; Reptiles & amphibians; Secretions; Skin; Skin diseases; Specialization; Amphiuma; Chytridiomycosis; Batrachochytrium dendrobatidis; Amphibian; Batrachochytrium salamandrivorans; Antimicrobial peptide
• ISSN: 0022-0949; 1477-9145
• DOI: 10.1242/JEB.183707

Amphibian skin is unique among vertebrate classes, containing a large number of multicellular exocrine glands that vary among species and have diverse functions. The secretions of skin glands contain a rich array of bioactive compounds including antimicrobial peptides (AMPs). Such compounds are important for amphibian innate immune responses and may protect some species from chytridiomycosis, a lethal skin disease caused by the fungal pathogens, (Bd) and (Bsal). While the bioactivity of skin secretions against Bd has been assessed for many amphibian taxa, similar studies are lacking for Bsal, a chytrid fungus that is especially pathogenic for salamanders. We studied the skin glands and their potential functions in the aquatic salamander, Three-toed Amphiuma ( ). Skin secretions of captive adult salamanders were analyzed by RP-HPLC and tested against the growth of Bd and Bsal using assays. We found that compounds within collected skin secretions were similar between male and female salamanders and inhibited the growth of Bd and Bsal. Thus, skin secretions that protect against Bd may also provide protection against Bsal. Histological examination of the skin glands of preserved salamanders revealed the presence of enlarged granular glands concentrated within caudal body regions. A site of potential gland specialization was identified at the tail base and may indicate specialized granular glands related to courtship and communication.