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アコヤガイの殻皮形成に関する電子顕微鏡的観察
https://fra.repo.nii.ac.jp/records/2009049
https://fra.repo.nii.ac.jp/records/200904977be3fbe-55f6-4d56-8530-4f0d7b964471
| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||
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| 公開日 | 2024-06-27 | |||||
| タイトル | ||||||
| タイトル | アコヤガイの殻皮形成に関する電子顕微鏡的観察 | |||||
| 言語 | ja | |||||
| タイトル | ||||||
| タイトル | Electron microscopic observations of the formation of the periostracum of Pinctada fucata | |||||
| 言語 | en | |||||
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| 言語 | jpn | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
| 資源タイプ | departmental bulletin paper | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
和田, 浩爾
× 和田, 浩爾 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | 1) 外褶内面上皮細胞と中褶外面上皮細胞とが接する位置，すなわち殻皮溝の一番奥に Basal Cell が外套周縁に沿って一列に並列している。 2) Basal Cell は他の外套上皮細胞と著しく異なり，細胞の中央でくびれ上端でふくらんだ洋梨形を示す。細胞の厚さは９～12μ で，その自由表面は中央に凹み（最深部で約４μ），そこに高さ0.5～1.0μ，基部の幅0.5～1.5μ の褶が６～10条ある。この褶は体の背腹軸に平行で外套周縁部に対して直角に走り，上下左右に波状に起伏する。 3) Basal Cell の分泌機能によって一枚の電子密度の高い膜（pellicle）がこの細胞の開口部近くで形成される。 4) pellicle は殻皮溝の奥部で折りたたまれて小褶曲と大褶曲とからなる樹枝状構造を示すが，外口部に近づくに従って褶曲の高さは低くなり，幅は広くなって，遂には波状ないし単純に折れ曲がった一枚の膜となる。 5) 中褶外面上皮―エオシン好性顆粒を含む腺細胞も含む―から放出された分泌物は pellicle の褶曲の間にたまって疎な微粒子層を形成するが，殻皮溝の外口部附近で流失する。 6) 外褶内面上皮から放出された分泌物は pellicle の内面に殻皮として発達しないため，アコヤガイの殻皮溝にみられる殻皮は pellicle の薄い単一膜からなる。 7) pellicle の単一膜は外套外褶の先端をまわって貝殻成長縁に連結し，その内面にメタクロマジアを示さない殻皮が外褶外面上皮によって形成される。 8) 外套外褶外面上皮は稜柱層の内表面をおおって殻皮と全く類似した染色性を示す有機質膜を時々形成する。この有機質膜は稜柱層の成長にともなって稜柱層中に閉じ込められ，水平な層として認められるので内殻皮（interperiostracum）と呼ぶことにする。 |
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| 言語 | ja | |||||
| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | In bivalvia, the site of mineralization is located between the mantle and periostracum, which is the covering of a shell, on the outside of the body. Previous reports have indicated that the periostracum is secreted by the epithelial cells lined on the inner side of the outer mantle fold (Yonge, 1957; Beedham, 1958a; Hillman, 1961), and is characteristic of a quinone-tanned protein (Beedham, 1958b; Hillman, 1961). From the biomineralogical point of view, the periostracum may serve functionally not only to make the appropriate site for formation and mineralization of a permineralized matrix but also as the substratum for mineralized layers (Wada, 1967, 1968b). Recently, several electron microscopic studies were made on the mantle of some bivalvia, and discussed relations between the structure and function of the epithelial cells of the outer and middle mantle folds with reference to the formation of periostracum. Kawaguchi and Ikemoto (1962) described a cell which connects the epithelial cells of both sides of the periostracal groove in the bivalved gastropod, and named it "basal cell". But they did not pay attention to the functional roles of the basal cell in the formation of periostracum. The detailed observation on the mantle edge of Macrocallista maculata by Bevelander and Nakahara (1967) have indicated that the basal cell elaborates "pellicle" which is the most outer layer of the periostracum and shows the periodic structure related with intracellular mechanism of the cell. Futhermore, they pointed out that the inner layers of the periostracum are formed on the inside of the pellicle by the cells located on the lower two-thirds of the outer mantle fold. On the other hand, Kawakami and Yasuzumi (1964) reported that the basement membrane of the outer mantle fold in the basal region of the periostracal groove of Pinctada fucata exhibits a folded or branch-like structure to expand an interior surface for the synthesis of protein. The present study was carried with the mantle edge of one year old Japanese pearl oyster Pinctada fucata collected in Ago Bay, Mie prefecture in Japan on June, 1967. The mantle was fixed according to the triple fixation of Sugihara et al. (1966) for electron microscopy. That is, several small pieces of the mantle edge were fixed in 6.25% solution of glutaraldehyde adjusted in Na-cacodylate buffer at pH 7.4 for 30~60 minutes. The fixed tissues were fixed in 3.3% solution of potassium dichromate buffered in phosphate buffer at pH 7.4 for 30 minutes. They were postfixed in 1 % solution of buffered osmium tetroxide at pH 7.4 for 1~2 hours. After fixation, tissues were dehydrated and embedded in Epon resin. Sections were stained with uranyl acetate saturated in 50% ethanol or Reynold's lead citrate solution. The basal cell. Fig. 2 is an electron micrograph of the basal part of the periostracal groove of Pinctada fucata and shows the presence of a specialized cell, so-called "basal cell", which markedly differs in appearance from other epithelial cells of the mantle. Basal cells form a row along the junction between the epithelial cells of the outer and middle mantle folds and connects them. The cell is about 9 μ~12 μ thick and pear-shaped (Figs. 3 and 4). Microvilli are absent on the free surface which is concave and plicate. The depth of the hollow measures about 4 μ. The cell has 6~10 lines of the plicae which are parallel each other, at right angle to the tangential line of the mantle and parallel to the dorso-ventral axis of the body (Figs. 1, 3, 6 and 7). The height of the plicae is about 0.5μ~1.0μ. The folded and concave free surface is electron-dense and exhibits the presence of secretory substances. The nucleus is located in the basal part near the central region of the cell. Mitochondria are scattered in the cytoplasm and concentrated in the plicae on the side adjacent to the epithelial cell of the outer mantle fold (Fig. 8). The cell contains numerous vesicles, vacuoles, granular endoplasmic reticulum and electron-dense granules (Figs. 3, 4, 5 and 8). The inner surface of the outer mantle fold. One or more epithelial cells of the outer mantle fold adjacent to the basal cell have irregularly arranged microvillus-like projections which bend to the outer region of the periostracal groove (Figs. 2, 7 and 9). Mitochondria are abundant in the distal region of the cell. The free surface of columnar epithelial cells of the outer mantle fold except them is provided with numerous microvilli (Figs. 2, 7, 8 and 9). They have numerous granular endoplasmic reticulum, vesicles and small and large vacuoles. The nucleus is situated in the distal part near the central region of the cell. Mitochondria are scattered and few in number. The Golgi apparatus is found in the cells located in the distal region of the mantle fold. The free surface of the epitherial cells swell up and will come off at the root marked by the arrows, as shown in Fig. 15. The terminal part of microvilli swell and is very often in a toy balloon-like expansion. The outer surface of the middle mantle fold. Some epithelial cells with different appearances are found in the basal region of the middle mantle fold. Several epithelial cells adjacent to the basal cell are more slender and lighter than other cells of the mantle fold (Figs. 2, 5, 7 and 9). The free surfaca is covered with numerous microvilli. Slender nucleus occupies in the distal part near the central ragion of the cell, a few mitochondria are scattered, and electron-densa granules are present in the distal part of the cell. Several epithelial cells located on the outside of the lighter cells are characteristic of the cytoplasm filled with numerous vacuoles, vasicles and endoplasmic reticulum (Figs. 9 and 12). The nuclaus is situated in the basal part of the cell. Epithelium are shorter immediately toward the middle ragion of the mantle fold, Few epithelial cell with unusual features as shown in Fig. 19 may be found between the shorter cells in the basal region of the mantle fold. Large numbers of ciliary epithelial cells with microvilli (Figs. 20, 21 and 23) are arranged zonally or in a cluster along the tangential line over the middle region to the distal region of the mantle fold. Characteristic profiles of the ciliary cells are numerous mitochondria distributed between the rootlets of cilia, as pointed out by Lee et al. (1965) and Kawakami (1966). They have small and large electron-dense granules in the distal part of the cell and the nucleus is situated in the basal part. The mucous cell. Secretory substance contained in mucous cells which lie between and under the epithelial cells of the mantle shows a typical metachromasia with 0.01 % toluidine blue solution of pH 3.4 and 7.0. Under an electron microscope, the secretory substance reveals a large granular appearance consisting of loose aggregation of fibers (Fig. 24). The large secretory granules are in the range of diameter of 0.7 μ to 3.8 μ, appear to be extruded into the periostracal groove by the macroapocrine mechanism classified by Kurozumi (1965) and then break up. The unicellular glandular cell with large eosinophilic granules. The glandular cells are concentrated under the epithelial cells which are located over the basal region in the middle region of the middle mantle fold of Pinctada fucata. These are filled with small and large granules in the range of diameter of 0.5μ to 4.5μ (Figs. 19, 20 and 24). The granules are electron-dense in the glandular cells under epithelial cells but sometimes reveal a loose aggregation of fine granules in the cells between epithelial cells (Fig. 24). Tsujii (1960) stated that the glandular cells distributed in the middle mantle fold are involved in the formation of the periostracum. The periostracum. A layer of electron-dense pellicle which is termed by Bevelander and Nakahara (1966) appears to originate in secretory substance extruded by the basal cell, but it can not be found as a layer or membrane in the folded and concave surface of the basal cell (Figs. 3 and 4). A dense pellicle is revealed in a narrow periostracal groove between the first epithelial cells of the outer and middle mantle folds neighboring on the basal cell and starts from the outlet of the hollow of the basal cell. The thickness of the pellicle is in the range of 60 mμ to 100 mμ over the whole region of the periostracal groove, but its appearance changes in different regions (Figs. 12, 13, 16 and 17). The membrane of the pellicle begins to be folded from the inner surface of the outer mantle fold toward the outer surface of the middle mantle fold, This occurs at the portion which the periostracal groove enlarges in the basal region of the mantle folds (Figs. 10 and 11) and thereafter is folded many times over. Consequently, the pellicle exhibits a complex, folded or branch-like appearance in the basal region of the groove in a longitudinal section of the mantle (Fig. 12). The width of folds of the pellicle increases in the middle region of the groove (Fig. 16) and at last it shows a simple wavy layer in the outer region (Fig. 17). Secretory substances (Figs. 10, 11, 16, 17 and 25) are present between the pellicle and the inner surface of the outer mantle fold, however this substances never develop in periostracum. The fine granular secretory substance (Figs. 13 and 25) embedded between the pellicle and the outer surface of the middle mantle fold disappears in the outer region of the groove. On the other hand, eosinophilic matrix which corresponds to periostracum is formed on the inner surface of the pellicle and prismatic layer through the outer epithelial cells located in the distal region of the outer mantle fold. The periostracum appears, therefore, to be added from the outer epithelial cells, and that enclosed in the prismatic layer may be called a "interperiostracum". The facts suggest that secretory substances extruded by the unicellular glandular cell with large eosinophilic granules, the outer epithelial cells of the middle mantle fold and the inner epithelial cells of the outer mantle fold appear not to transform into the constituent parts of the periostracum in Pinctada fucata. | |||||
| 言語 | en | |||||
| 書誌情報 |
ja : 国立真珠研究所報告 en : Bulletin of the National Pearl Research Laboratory 巻 13, p. 1540-1560, ページ数 21, 発行日 1968-07-05 |
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| 出版者 | ||||||
| 出版者 | 国立真珠研究所 | |||||
| 言語 | ja | |||||
| 出版者 | ||||||
| 出版者 | National Pearl Research Laboratory | |||||
| 言語 | en | |||||
| 書誌レコードID | ||||||
| 収録物識別子タイプ | NCID | |||||
| 収録物識別子 | AN00091717 | |||||
| 情報源 | ||||||
| 識別子タイプ | Local | |||||
| 関連識別子 | pearl_k_1540 | |||||
| 関連サイト | ||||||
| 識別子タイプ | URI | |||||
| 関連識別子 | https://jp-pearl.com/wp-content/uploads/2018/06/houkoku013.pdf#002 | |||||
| 言語 | ja | |||||
| 関連名称 | 日本真珠振興会Archive | |||||
