Sire J Y
Laboratoire d'Anatomie comparée, Université Paris 7, CNRS, URA 1137, France.
Anat Rec. 1994 Oct;240(2):189-207. doi: 10.1002/ar.1092400206.
The structure of nonregenerated and experimentally regenerated scales of the holostean fish Lepisosteus oculatus and the events taking place before and during ganoine deposition on the scale surface were studied. The aim of this study was to answer the question of the origin of the ganoine in lepisosteids, the scales of which are devoid of dentine, and to compare them to ganoine formation in polypterid scales and to enamel formation in teeth.
Two adult specimens were used and the scale structure was studied using light and transmission electron microscopy. Regeneration was used as an alternative to the lack of developmental stages and to induce ganoine deposition on the scale surface.
Nonregenerated scales are composed of a thick, avascular bony plate capped by ganoine that is covered either by the epidermis or by dermal elements. The ganoine surface is separated from the covering soft tissues by an unmineralized layer, the ganoine membrane. During the first 2 months of regeneration, the bony plate forms. It differs from the bony plate of nonregenerated scales only by its large, woven-fibered central region and by the presence of numerous vascular canals. Shortly before ganoine deposition, the osteoblasts cease their activity and an epithelial sheet comes to contact them and spreads on the bony surface. This epithelial sheet is connected to the epidermis by a short epithelial bridge only and is composed of two layers: the inner ganoine epithelium (IGE), in contact with the bone surface and composed of juxtaposed columnar cells that synthesize the ganoine matrix, preganoine; the outer ganoine epithelium (OGE), composed of elongated cells, the surface of which is separated from the overlying dermal space by a basal lamina. Isolated patches of preganoine are deposited by the IGE cells in the upper part of the osteoid matrix of the scale. The interpenetrated preganoine and osteoid matrices constitute an anchorage zone between ganoine and bone. Preganoine patches fuse and a continuous layer of preganoine is progressively synthesized by the IGE cells. Preganoine progressively mineralizes to become ganoine.
The processes of ganoine formation are similar to those known for the ganoine in the polypterid scales and to those described for enamel deposition in teeth. Ganoine is enamel.
对全骨鱼类眼斑雀鳝未再生及实验再生鳞片的结构，以及鳞片表面硬鳞质沉积之前和期间发生的事件进行了研究。本研究的目的是回答雀鳝类硬鳞质的起源问题，其鳞片不含牙本质，并将它们与多鳍鱼鳞片中的硬鳞质形成以及牙齿中的釉质形成进行比较。
使用了两个成年标本，并通过光学显微镜和透射电子显微镜研究鳞片结构。利用再生来替代缺乏发育阶段的情况，并诱导硬鳞质在鳞片表面沉积。
未再生的鳞片由一层厚厚的无血管骨板组成，上面覆盖着硬鳞质，硬鳞质要么被表皮覆盖，要么被真皮成分覆盖。硬鳞质表面通过未矿化的硬鳞质膜与覆盖的软组织分隔开。在再生的前两个月，骨板形成。它与未再生鳞片的骨板的不同之处仅在于其大的、编织纤维状的中央区域以及存在许多血管管道。在硬鳞质沉积前不久，成骨细胞停止活动，一层上皮细胞与它们接触并在骨表面扩散。这层上皮细胞仅通过一个短的上皮桥与表皮相连，由两层组成：内层硬鳞质上皮（IGE），与骨表面接触，由并列的柱状细胞组成，这些细胞合成硬鳞质基质，即前硬鳞质；外层硬鳞质上皮（OGE），由细长细胞组成，其表面通过基膜与上方的真皮空间分隔开。前硬鳞质的孤立斑块由IGE细胞沉积在鳞片类骨质基质的上部。相互穿插的前硬鳞质和类骨质基质构成了硬鳞质与骨之间的锚固区。前硬鳞质斑块融合，IGE细胞逐渐合成一层连续的前硬鳞质。前硬鳞质逐渐矿化成为硬鳞质。
硬鳞质的形成过程与多鳍鱼鳞片中硬鳞质的已知过程以及牙齿中釉质沉积的描述过程相似。硬鳞质就是釉质。
