The role of desmosomes in the ear plug formation in the bowhead whale (Balaena mysticetus).

Autor: Rehorek SJ; Department of Biology, Slippery Rock University, Slippery Rock, Pennsylvania., Stimmelmayr R; Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska.; Department of Wildlife Management, North Slope Borough, Alaska., George JC; Department of Wildlife Management, North Slope Borough, Alaska., Suydam R; Department of Wildlife Management, North Slope Borough, Alaska., McBurney DL; Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio., Thewissen JGM; Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio.
Jazyk: angličtina
Zdroj: Anatomical record (Hoboken, N.J. : 2007) [Anat Rec (Hoboken)] 2020 Dec; Vol. 303 (12), pp. 3035-3043. Date of Electronic Publication: 2019 Dec 28.
DOI: 10.1002/ar.24338
Abstrakt: The external acoustic meatus (EAM) of most baleen whales accumulates cellular debris annually in the lumen as whales age, forming a lamellated ear plug. The bowhead whale ear plug is formed from annually molting lining of the EAM as the entire epithelium releases at the level of the stratum basale during the spring migration. Epithelial regeneration is mostly completed by the fall migration, remaining intact for 6-7 months before being torn off the following spring. Desmosomes are integral to cell-cell adhesion with connecting desmosomal cadherins desmoglein (dsg) and desmocollin (dsc). Paraffin sections of the oral cavity and EAM lining of spring and fall adult bowhead whales, as well as the EAM of spring-caught juvenile, were immunohistochemically examined for the presence of these cadherins. In all fall specimens, both cadherins occurred in all layers except the superficial keratinous layer of the oral cavity. In spring, three different conditions existed: (a) oral cavity of spring-caught adults had reduced cadherins, with superficial fissuring in its keratinized layer and vacuolation in the upper stratum spinosum; (b) EAM of juvenile spring-caught whales displayed fissuring with accompanying reduction of both cadherins in its superficial lining; and (c) EAM lining of spring-caught adults displayed deep fissures, reduced cadherins, and absence of dsc1 in the fissuring zone. These results suggest that shedding of skin layers in mammals, whether normal molting, pathological, or the result of injury and wound repair all revolve around desmosome function. The specific role, structure, and location of these two cadherins need to be further addressed.
(© 2019 American Association for Anatomy.)
Databáze: MEDLINE
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