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

Title

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

Creator

Rehorek Susan J; Stimmelmayr Raphaela; George John Craig; Suydam Robert; McBurney Denise L; Thewissen J G M

Publisher

Anatomical Record (Hoboken, N.J.: 2007)

Date

2019
2019-12-19

Description

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.

Subject

desmosomes; ear plug; external acoustic meatus

Identifier

PMID: 31854140

Format

Journal Article

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Rights

Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).

ISSN

1932-8494

NEOMED College

NEOMED College of Medicine

NEOMED Department

Department of Anatomy & Neurobiology

Update Year & Number

January 2020 Update

Citation

Rehorek Susan J; Stimmelmayr Raphaela; George John Craig; Suydam Robert; McBurney Denise L; Thewissen J G M, “The role of desmosomes in the ear plug formation in the bowhead whale (Balaena mysticetus),” NEOMED Bibliography Database, accessed December 3, 2021, https://neomed.omeka.net/items/show/10943.

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