The Mineralization of Crystalline Inorganic Components in Japanese Serow Horn

Hashiguchi, Kunio; Hashimoto, Kenji

doi:10.2535/ofaj1936.72.5_235

Cited by 8 publications

(4 citation statements)

References 18 publications

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“…Keratinization and cornification of epidermal cells in hardcornified skin modifications may be accompanied by calcification (Toto et al 1967). For example, keratin filaments of the hard-cornified horn of the Japanese serow (Capricornis crispus) contain crystalline inorganic components, including tricalcium phosphate and hydroxyapatite (Hashiguchi & Hashimoto, 1995). In the Saiga antelope (Saiga tatarica), the hard-keratinized Stratum corneum is mineralized with deposits of octacalcium phosphate (Hashiguchi et al 2001).…”

Section: Calcification Of Keratins In Hard-cornified Skin Modificationsmentioning

confidence: 99%

Structure and functions of keratin proteins in simple, stratified, keratinized and cornified epithelia

Bragulla¹,

2009

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Historically, the term 'keratin' stood for all of the proteins extracted from skin modifications, such as horns, claws and hooves. Subsequently, it was realized that this keratin is actually a mixture of keratins, keratin filament-associated proteins and other proteins, such as enzymes. Keratins were then defined as certain filament-forming proteins with specific physicochemical properties and extracted from the cornified layer of the epidermis, whereas those filamentforming proteins that were extracted from the living layers of the epidermis were grouped as 'prekeratins' or 'cytokeratins'. Currently, the term 'keratin' covers all intermediate filament-forming proteins with specific physicochemical properties and produced in any vertebrate epithelia. Similarly, the nomenclature of epithelia as cornified, keratinized or non-keratinized is based historically on the notion that only the epidermis of skin modifications such as horns, claws and hooves is cornified, that the non-modified epidermis is a keratinized stratified epithelium, and that all other stratified and non-stratified epithelia are non-keratinized epithelia. At this point in time, the concepts of keratins and of keratinized or cornified epithelia need clarification and revision concerning the structure and function of keratin and keratin filaments in various epithelia of different species, as well as of keratin genes and their modifications, in view of recent research, such as the sequencing of keratin proteins and their genes, cell culture, transfection of epithelial cells, immunohistochemistry and immunoblotting. Recently, new functions of keratins and keratin filaments in cell signaling and intracellular vesicle transport have been discovered. It is currently understood that all stratified epithelia are keratinized and that some of these keratinized stratified epithelia cornify by forming a Stratum corneum . The processes of keratinization and cornification in skin modifications are different especially with respect to the keratins that are produced. Future research in keratins will provide a better understanding of the processes of keratinization and cornification of stratified epithelia, including those of skin modifications, of the adaptability of epithelia in general, of skin diseases, and of the changes in structure and function of epithelia in the course of evolution. This review focuses on keratins and keratin filaments in mammalian tissue but keratins in the tissues of some other vertebrates are also considered.

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Section: Calcification Of Keratins In Hard-cornified Skin Modificationsmentioning

confidence: 99%

Structure and functions of keratin proteins in simple, stratified, keratinized and cornified epithelia

Bragulla¹,

2009

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“…Cooccurrence of melanin and calcium (as octocalcium phosphate) has been noted in the horns of saiga (Saiga tatarica) (Hashiguchi et al, 2001). The presence of higher concentrations of calcium can be interpreted as a primary mechanism and not a pathological finding, as several other forms of horny tissue aside from rhino and saiga horn also contain appreciable portions of hydroxyapatite or octocalcium phosphate (Arnott and Pautard, 1968;Pautard, 1970;Hashiguchi et al, 1995).…”

Section: Co-occurrence Of Radiodense Features and Dark Periodic Bandsmentioning

confidence: 99%

Structure of white rhinoceros (Ceratotherium simum) horn investigated by X-ray computed tomography and histology with implications for growth and external form

2006

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The nasal and frontal horns of two individuals of Ceratotherium simum were examined by x-ray computed tomography (CT scanning), gross observation of sectioned horn, and light microscopy of histological sections of the horn tissue. CT scans of both sets of horns reveal a periodic banding pattern that is evident upon gross observation of sections as darker bands of tissue. The overlap of these bands in both histological and CT slices suggests the presence of both a photoabsorbent component (melanin) and a radiodense component (calcium phosphate salts, most likely hydroxyapatite or octocalcium phosphate). The distribution of these two components in the horns is hypothesized to contribute to the differential wear patterns that produce the characteristic sweeping conical shape of rhinoceros horn from what otherwise (in the absence of wear and UV exposure) would be cylindrical blocks of constantly growing cornified papillary epidermis. Although extant rhinocerotids are unique in possessing a massive entirely keratinous horn that approximates the functions of keratin-and-bone horns such as those of bovid artiodactyls, the tissue structures that make up the horn are strikingly convergent with other examples of papillary cornified epidermis found in horses, artiodactyls, cetaceans, and birds.

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“…In previous report (Hashiguchi K et al, 1995), the mineral phases in the presence of Mg contained in Japanese serow horn has been studied using TEM, ICP and X-ray diffraction method. After heating at 800 °C, the main component of the remaining ash was HA.…”

Section: Discussionmentioning

confidence: 99%

Morphological Character of Crystalline Components Present in Saiga Horn

Hashiguchi

Hashimoto

Akao

2001

Okajimas Folia Anatomica Japonica

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Summary: The purpose of this study was to investigate the ultrastructure of saiga-antelope (Saiga tatarica) horn for proposing the mechanism of the initial mineralization. Horn is derived from horny tooth of Cyclostomata. The minerals in saiga horn were identified crystallographically using electron microscopy and X-ray diffraction techniques. Soft X-ray photographs revealed the degree of the mineralization pattern. However, the number of rings did not indicate the age of saiga.Mineral deposites were observed among well banded keratin fibers and composed of powder like crystals. This deposited crystals were found by the X-ray diffraction method to be octacalcium phospate (OCP) by comparing these periodic lattice fringes to JCPDS card data The chemical formula of OCP is Ca8H2(PO4)6 5H2O. Evidences for the presence of OCP in mature hard tissues have never been obtained. This phenomenon described here may be characteristic of saiga horn because we have found no reports on this type of OCP mineralization in any other animal species. It is possible that OCP is the precursor in the initial mineralization step, indicating in a nucleation of mineral on the keratin fibers.

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The Mineralization of Crystalline Inorganic Components in Japanese Serow Horn

Cited by 8 publications

References 18 publications

Structure and functions of keratin proteins in simple, stratified, keratinized and cornified epithelia

Structure and functions of keratin proteins in simple, stratified, keratinized and cornified epithelia

Structure of white rhinoceros (Ceratotherium simum) horn investigated by X-ray computed tomography and histology with implications for growth and external form

Morphological Character of Crystalline Components Present in Saiga Horn

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