Soluble scute proteins of healthy and ill desert tortoises (Gopherus agassizii)

Homer, Bruce L.; Li, C.; Berry, Kristin H.; Denslow, Nancy D.; Jacobson, Elliott R.; Sawyer, Roger H.; Williams, Jeannette E.

doi:10.2460/ajvr.2001.62.104

Cited by 30 publications

(19 citation statements)

References 27 publications

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“…However, normal fibroblasts and striated muscular cells of these turtles showed mild red immunoreactivity using the vimentin and desmin antisera respectively. The major protein components of scales and shell scute of reptiles are β-keratins (Wyld & Brush 1983, Homer et al 2001). The molecular weight of avian and certain reptilian β-keratins ranges from 10 to 30 kDa, whereas the molecular weight of α-keratins of vertebrate epithelia ranges from 40 to 70 kDa (Gregg & Rogers 1986, Marshall et al 1991.…”

Section: Discussionmentioning

confidence: 99%

Metastatic squamous cell carcinoma in two loggerhead sea turtles Caretta caretta

Orós

Tucker²,

Fernández³

et al. 2004

Dis. Aquat. Org.

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We received 2 stranded loggerhead sea turtles (Caretta caretta) with squamous cell carcinomas to necropsy. The dead turtles had been collected in Gran Canaria and Fuerteventura in April 1994 and May 1997, respectively to determine the cause of death. One turtle had 3 ulcerated lesions in the dorsal part of the neck and several irregular masses in the lungs and kidneys. Histologic examination of lesions in the skin, lungs, kidneys, and ventricular myocardium revealed neoplastic proliferation of abnormal keratinocytes. Ultrastructural examination identified the tumoral cells as epithelial cells. The second turtle had 4 lesions in the skin of the head and flippers, and several irregular masses in the lungs, liver, and kidneys. Histological examination revealed a squamous cell carcinoma with metastases to muscle tissue, liver, lungs, and kidneys. Attempts to characterize the tumoral cells by immunohistochemistry using several monoclonal and polyclonal antisera against high and low molecular weight cytokeratins from mammals, as well as vimentin and desmin, failed. Differences between reptilian keratins (mainly β-keratins) and mammalian keratins (mainly α-keratins) could explain this absence of immunoreactivity. This is the first description of squamous cell carcinoma in sea turtles. KEY WORDS: Squamous cell carcinoma · Loggerhead turtle · Caretta caretta · Sea turtle · Reptile · Immunohistochemistry Resale or republication not permitted without written consent of the publisherDis Aquat Org 58: [245][246][247][248][249][250] 2004 of 20 to 30 turtles per year. We report here the histopathological features of 2 cases of metastasizing squamous cell carcinoma in the loggerhead sea turtle Caretta caretta. MATERIALS AND METHODSWithin a 3 yr period (i.e. in April 1994 and May 1997), 2 stranded loggerhead sea turtles with squamous cell carcinomas were submitted to the Veterinary Faculty, ULPGC. The first was a 6.5 kg juvenile female stranded in Gran Canaria (27°40' N, 15°20' W). The turtle had a curved carapace length and width of 33 and 31 cm respectively, and a straight carapace length and width of 29 and 28 cm respectively. After stranding, the turtle had been housed in an aquarium at the Wildlife Rehabilitation Center of Tafira, Gran Canaria. Physical examination had revealed anorexia and lethargy. Despite forcefeeding and intramuscular administration of antimicrobial enrofloxacin, the turtle died 1 wk after stranding. The second turtle was a 7.2 kg juvenile female found stranded dead in Fuerteventura (28°10' N, 14°20' W). This turtle had a curved carapace length and width of 34 and 33 cm respectively, and a straight carapace length and width of 31 and of 30 cm respectively.The gross postmortem examinations of both turtles were carried out using the protocol developed by Wolke & George (1981). Fecal specimens were processed following techniques described by Boch & Supperer (1982).Macroscopic lesions were recorded and tissue samples from all major organs were fixed in 10% neutral buffered formalin, embedded i...

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Section: Discussionmentioning

confidence: 99%

Metastatic squamous cell carcinoma in two loggerhead sea turtles Caretta caretta

Orós

Tucker²,

Fernández³

et al. 2004

Dis. Aquat. Org.

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“…Previous studies on reptilian β‐keratins have indicated that there are several forms of these small proteins with molecular weight ranging between 10 and 25 kDa (Wyld and Brush,1979, 1983; Thorpe and Giddings,1981; Sawyer et al,2000; Homer et al,2001; Alibardi and Toni,2006). Snake β‐keratins cross‐react with antibodies directed against chick scale β‐keratins suggesting that some amino acid sequences (epitopes) such as those of chick and other reptiles are also present in snake β‐keratins (Alibardi and Sawyer,2002).…”

Section: Introductionmentioning

confidence: 99%

β‐keratins of differentiating epidermis of snake comprise glycine‐proline‐serine‐rich proteins with an avian‐like gene organization

Valle

Nardi

Belvedere

et al. 2007

Developmental Dynamics

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␤-keratins of reptilian scales have been recently cloned and characterized in some lizards. Here we report for the first time the sequence of some ␤-keratins from the snake Elaphe guttata. Five different cDNAs were obtained using 5 -and 3 -RACE analyses. Four sequences differ by only few nucleotides in the coding region, whereas the last cDNA shows, in this region, only 84% of identity. The gene corresponding to one of the cDNA sequences has a single intron present in the 5 -untranslated region. This genomic organization is similar to that of birds' ␤-keratins. Cloning and Southern blotting analysis suggest that snake ␤-keratins belong to a family of high-related genes as for geckos. PCR analysis suggests a head-to-tail orientation of genes in the same chromosome. In situ hybridization detected ␤-keratin transcripts almost exclusively in differentiating oberhautchen and ␤-cells of the snake epidermis in renewal phase. This is confirmed by Northern blotting that showed, in this phase, a high expression of two different transcripts whereas only the longer transcript is expressed at a much lower level in resting skin. The cDNA coding sequences encoded putative glycine-proline-serine rich proteins containing 137-139 amino acids, with apparent isoelectric point at 7.5 and 8.2. A central region, rich in proline, shows over 50% homology with avian scale, claw, and feather keratins. The prediction of secondary structure shows mainly a random coil conformation and few ␤-strand regions in the central region, likely involved in the formation of a fibrous framework of ␤-keratins. This region was possibly present in basic reptiles that originated reptiles and birds.

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“…Beta keratins in reptiles and birds have a molecular weight lower than 40 kDa (10-32 kDa, Wyld and Brush, '79;Gregg and Rogers, '86;Sawyer et al, 2000Sawyer et al, , 2003Holmer et al, 2001), and associate to form 3-4 nm thick filaments. Betakeratin molecules in scales can self-assemble without any matrix protein.…”

Section: Transglutaminase and Beta-keratinizationmentioning

confidence: 99%

Immuno‐Cross reactivity of transglutaminase and cornification marker proteins in the epidermis of vertebrates suggests common processes of soft cornification across species

Alibardi

Toni

2004

J Exp Zool Pt B

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In differentiating mammalian keratinocytes proteins are linked to the plasma membrane by epidermal transglutaminases through N-epsilon-(gamma-glutamyl)-lysine isopeptide bonds to form the cornified cell envelope. The presence of transglutaminases and their protein substrates in the epidermis of nonmammalian vertebrates is not known. The present study analyses the presence and localization of the above proteins in the epidermis using immuno-cross reactivity across different classes of amniotes. After immunoblotting, some protein bands appear labelled for loricrin, sciellin, and transglutaminase in most species. These proteins are scarce to absent in the epidermis of aquatic species (goldfish and newt) where a stratum corneum is absent or very thin. The molecular weight of transglutaminase immunoreactive bands generally varies between 40 to 62 kDa, with the most represented bands at 52-57 kDa in most species. The more intense loricrin- and sciellin-immunoreactive bands are seen at 50-55-62 kDa, but are weak or absent in aquatic vertebrates. Loricrine-like immunoreactivity is present in the epidermis where alpha-(soft)-keratinization occurs. Isopeptide bonds are mainly associated to bands in the range of 50-62 kDa. In vertebrates where hard-keratin is expressed (the beta-keratin corneous layer of sauropsids and in feathers) or in hair cortex of mammals, no loricrin-like, transglutaminase-, and isopeptide-bond-immunoreactivities are seen. Immunoblotting however shows loricrin-, sciellin-, and trasnsglutaminase-positive bands in the corneous layers containing beta-keratin. Histologically, the epidermis of most amniotes shows variable transglutaminase immunoreactivity, but isopeptide-bond and sciellin immunoreactivities are weak or undetactable in most species. The limitations of immunohistochemical methods are discussed and compared with results from immunoblotting. In reptilian epidermis transglutaminase is mainly localized in 0.15-0.3 microm dense granules or diffuse in transitional alpha-keratogenic cells. In beta-keratogenic cells few small dense granules show a weak immunolabeling. Transglutaminase is present in nuclei of terminal differentiating alpha- and beta-keratinocytes, as in those of mature inner and outer root sheath. The present study suggests that keratinization based on loricrin, sciellin and transglutaminase was probably present in the stratum corneoum of basic amniotes in the Carboniferous. These proteins were mainly maintained in alpha-keratogenic layers of amniotes but decreased in beta-keratogenic layers of sauropsids (reptiles and birds). The study suggests that similar proteins for the formation of the cornified cell envelope are present in alpha-keratinocytes across vertebrates but not in beta-keratinocytes.

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Soluble scute proteins of healthy and ill desert tortoises (Gopherus agassizii)

Abstract: The major protein components of shell scute of desert tortoises have amino acid composition and antigenic features of beta keratins. Scute protein composition may be altered in tortoises with certain systemic illnesses.

Cited by 30 publications

References 27 publications

Metastatic squamous cell carcinoma in two loggerhead sea turtles Caretta caretta

Metastatic squamous cell carcinoma in two loggerhead sea turtles Caretta caretta

β‐keratins of differentiating epidermis of snake comprise glycine‐proline‐serine‐rich proteins with an avian‐like gene organization

Immuno‐Cross reactivity of transglutaminase and cornification marker proteins in the epidermis of vertebrates suggests common processes of soft cornification across species

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