A STUDY OF THE FINE STRUCTURE OF THE EPIDERMIS OF <i>RANA PIPIENS </i>

Parakkal, Paul F.; Matoltsy, A. Gedeon

doi:10.1083/jcb.20.1.85

Cited by 112 publications

(52 citation statements)

References 23 publications

(21 reference statements)

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“…Amphibian epidermis is a stratified epithelium that is continuously replaced by its basal stratum (stratum germinativum). Daughter cells of these columnar basal cells move outward, becoming cuboidal or polyhedral in the intermediate stratum (stratum spinosum) and then gradually flattening in the replacement stratum (stratum granulosum) into a cornified sheet in the corneal stratum (stratum corneum) that is routinely shed (Parakkal & Matoltsy 1964, Farquhar & Palade 1965, Alibardi 2001. Although it seems that all post-metamorphic anurans and urodeles are capable of hosting Bd in the outermost epidermal cell layers, host response (i.e.…”

Section: Introductionmentioning

confidence: 99%

Host invasion by Batrachochytrium dendrobatidis: fungal and epidermal ultrastructure in model anurans

Greenspan¹,

Longcore²,

Calhoun³

2012

Dis. Aquat. Org.

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The chytridiomycete fungus Batrachochytrium dendrobatidis (Bd) colonizes mouthparts of amphibian larvae and superficial epidermis of post-metamorphic amphibians, causing the disease chytridiomycosis. Fungal growth within host cells has been documented by light and transmission electron microscopy; however, entry of the fungus into host cells has not. Our objective was to document how Bd enters host cells in the wood frog Lithobates sylvaticus, a species at high mortality risk for chytridiomycosis, and the bullfrog L. catesbeianus, a species at low mortality risk for chytridiomycosis. We inoculated frogs and documented infection with transmission electron microscopy. Zoospores encysted on the skin surface and produced morphologically similar germination tubes in both host species that penetrated host cell membranes and enabled transfer of zoospore contents into host cells. Documenting fungal and epidermal ultrastructure during host invasion furthers our understanding of Bd development and the pathogenesis of chytridiomycosis. KEY WORDS: Chytridiomycosis · Morphology · Transmission electron microscopy · Lithobates catesbeianus · Lithobates sylvaticus Resale or republication not permitted without written consent of the publisherDis Aquat Org 100: [201][202][203][204][205][206][207][208][209][210] 2012 scopically, excessive skin sloughing, lethargy, anorexia, loss of righting reflex, and abnormal posture may be observed (Nichols et al. 2001, Daszak et al. 2004) but often not until immediately before death (Bradley et al. 2002, Parker et al. 2002. Proximate cause of death is inhibition of electrolyte transport across epidermis and subsequent disruption of cardiac electrical activity (Voyles et al. 2009).The asexual life cycle of Bd consists of a motile zoospore stage and a stationary thallus stage (Berger et al. 2005). Zoospores are flagellated and are not bounded by a cell wall. After a motile period, usually lasting ≤24 h, a zoospore encysts (i.e. attaches to a substrate, retracts the flagellum, and forms a wall of chitin around the spore body). Morphology after encystment depends on substrate type. On nutrient media, an encysted zoospore develops into a single or colonial (internally divided) zoosporangium (endogenous growth); root-like rhizoids originating from 1 or more points on the zoosporangium may be numerous . In an amphibian host, cellular contents of a superficially encysted zoospore leave the cyst and enter a host cell (exogenous growth), inside which a single or colonial zoosporangium develops; rhizoids are usually less abundant than on nutrient media (Berger et al. 2005). The specifics of amphibian host invasion by Bd (i.e. the morphological process by which zoospore contents are transferred from a cyst into a host cell) have not been reported. In other chytrid species with known developmental morphologies (saprophytes and patho gens of plants, algae, protists, and invertebrates), endobiotic (i.e. intracellular) growth of a thallus is initiated when a protrusion of the zoospore cyst wall e...

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Section: Introductionmentioning

confidence: 99%

Host invasion by Batrachochytrium dendrobatidis: fungal and epidermal ultrastructure in model anurans

Greenspan¹,

Longcore²,

Calhoun³

2012

Dis. Aquat. Org.

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“…According to Lillywhite and Licht (1974), grooves can work as water distribution channels by a capillarity mechanism from one integument surface to another. Several authors have proposed that water distribution keeps the integument moist, protecting the animal against desiccation (Parakkal and Matoltsy 1964, Machin 1969, Duellman and Trueb 1994, de Brito-Gitirana and Azevedo 2005.…”

Section: O Albicansmentioning

confidence: 99%

Comparative analysis of the integument of different tree frog species from Ololygon and Scinax genera (Anura: Hylidae)

Silva¹,

Silva-Soares²,

Brito-Gitirana³

2017

Zoologia

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ABSTRACT. The integuments of ten treefrog species of two genera from Scinaxnae -O. angrensis (Lutz, 1973), O. flavoguttata (Lutz & Lutz, 1939), O. humilis (Lutz & Lutz, 1954), O. perpusilla (Lutz & Lutz, 1939), O. v-signata (Lutz, 1968, Scinax hayii (Barbour, 1909), S. similis (Cochran, 1952), O. trapicheroi (Lutz & Lutz, 1954) and S. x-signatus (Spix, 1824) -were investigated using conventional and histochemical techniques of light microscopy, and polarized light microscopy. All integuments showed the basic structure of the anuran integument. Moreover, the secretory portions of exocrine glands, such as serous merocrine and apocrine glands, were found to be restricted to the spongious dermis. Lipid content occurred together with the heterogeneous secretory material of the glands with an apocrine secretion mechanism. In addition, clusters of these apocrine glands were present in the ventrolateral integument of some species. Melanophores were also visualized in all examined hylids. However, the occurrence of iridophores, detected through polarized light microscopy, varied according to the species. The Eberth-Katschenko layer occurred in the dorsal integument from both genera, but it was only present in the ventral integument of O. albicans, O. angrensis, O. flavoguttata, O. perpusilla and O. v-signata. Although the integument of all treefrogs showed the same basic structure, some characteristics were genus-specific; however, these features alone may not be used to distinguish both genera.

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“…In amphibians and reptiles, the epidermal keratinocytes possess numerous mucous secretory granules (Parakkal & Matoltsy 1964;Matoltsy & Huszar 1972;Whitear 1977;Fox 1986;Alibardi 2001). The latter are generally not formed in keratinocytes of birds and mammals (Matoltsy 1986;Menon & Menon 2000).…”

Section: Discussionmentioning

confidence: 99%

“…However, the large mucous granules detected in the outer cornified cells of AO seem to play a role in this process. In the epidermis of teleost, amphibia and reptilia, these granules are believed to be involved in matrix densification and clumping of the tonofilaments together in cells undergoing keratinisation (Parakkal & Matoltsy 1964;Budtz & Larsen 1975;Fox 1986;Whitear 1986). In birds and mammals, keratohyalin granules play a role in filament aggregation during keratinisation of the epidermal cells.…”

Section: Discussionmentioning

confidence: 99%

“…The substances that glue the tonofilaments together are at present unknown, but mucous granules have been implicated in this process (see Alibardi 2001). Of the two types of mucous granules described for the teleost epidermis, the large variety found in the outer cells has been supposed to be involved in matrix densification and clumping of the tonofilaments together (Parakkal & Matoltsy 1964;Whitear 1986). On the other hand, in birds and mammals, keratohyalin granules play a role in filament aggregation during keratinisation of the epidermal cells.…”

Section: Introductionmentioning

confidence: 99%

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Morphology of adhesive organ of the snow troutSchizothorax richardsonii(Gray, 1832)

Das¹,

Nag²

2008

Italian Journal of Zoology

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This paper describes the morphology and fine structure of adhesive organ (AO) of the snow trout Schizothorax richardsonii (Gray, 1832). The species lives in the sub-Himalayan streams and rivers, where they adhere to submerged rocks and stones with its AO located beneath the mouth opening. The AO consists of a crescent callus part and a modified labial fold, bearing numerous tubercles. In both parts, the epidermis is exceptionally thick (150-170 mm) and contains keratinocytes rich in bundles of tonofilaments; elsewhere, the epidermis contains single, disperse filaments, mucous cells and other usual cells seen in teleosts. Unlike epidermis elsewhere, the outer 4-5 row cells of the AO epidermis undergo keratinisation and are cytokeratin positive. The individual keratinised cell layers, which are degenerated electron-dense sheets, lack nuclei and cytoplasmic organelles, but possess filaments embedded in a dense cytoplasmic matrix and few, large mucous-like granules. Beneath the keratinised layers, keratinocytes are compactly aligned into 20-25 rows. They possess abundant thick bundles of clumped tonofilaments over the entire cytoplasm and peripherally, small mucous granules. Towards the basal epidermis, the cells are elongated and show major cytoplasmic organelles, few tonofilament bundles, but no mucous granules. It is evident that the keratinocytes of the mid-epidermis are differentiated for the production of tonofilaments. The outer keratinised part of the AO epidermis provides structural support and protection (from damage) during adhesion. It appears that the callus part acts by creating vacuum first, while the tuberculated part of the AO epidermis assists in adhesion to the rocky substratum.

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A STUDY OF THE FINE STRUCTURE OF THE EPIDERMIS OF RANA PIPIENS

Cited by 112 publications

References 23 publications

Host invasion by Batrachochytrium dendrobatidis: fungal and epidermal ultrastructure in model anurans

Host invasion by Batrachochytrium dendrobatidis: fungal and epidermal ultrastructure in model anurans

Comparative analysis of the integument of different tree frog species from Ololygon and Scinax genera (Anura: Hylidae)

Morphology of adhesive organ of the snow troutSchizothorax richardsonii(Gray, 1832)

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