Differentiation of the epidermis during scale formation in embryos of lizard
Differentiation of the epidermis during scale formation in embryos of lizard
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DOI：
10.1046/j.1469-7580.1998.19220173.x
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发表时间：
1998-02-01
影响因子：
2.4
通讯作者：
Alibardi, L
中科院分区：
文献类型：
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作者：
Alibardi, L
用电子显微镜研究了蜥蜴Anolis lineatopus和Podarcis muralis鳞片发育过程中第一代表皮的形成，特别是脱落复合体的形成。表皮由原来的线形双层变为对称的乳头状突起，形成不对称的鳞片。外周层比下面的层更电子致密，暂时命名为“内周层”，但可能来自基底层。粗厚的花丝逐渐充满内周膜的细胞质或形成类似于鸟类周膜颗粒的网状体。周皮细胞在卵内轻微脱落。从基底层产生各种基底上上皮层。第一层含有透明角质蛋白样颗粒，被鉴定为透明层。在它的下面是一个刺状（Anolis）或锯齿状（Podarcis）oberhautchen分化。透明层和“oberhautchen”层构成第一个脱落复合体。脱落的第一表皮层由剥落的表皮层或表皮层与透明层组成。中胚层的分化是在孵化前进行的，此时表皮形态类似于成虫脱落周期的第4-5阶段。鳞片内侧的成纤维细胞与基底膜接触较少，其胞质延伸方向多与致密层平行。相反，外鳞片表面（BLOS）的基底层下的成纤维细胞与基底膜进行了大量接触，这表明更多的真皮-表皮相互作用发生在鳞片的这一侧。
The formation of the first epidermal generations and in particular of the shedding complex in the developing scales of the lizards Anolis lineatopus and Podarcis muralis was studied by electron microscopy. The initially linear and bilayered epidermis turned into symmetric papillae, which became asymmetric scales. The outer periderm was more electrondense than the following layer, provisionally named 'inner periderm' but probably derived from the basal layer. Coarse thick filaments progressively filled the cytoplasm of the inner periderm or formed reticulate bodies resembling avian peridermal granules. Peridermal cells cornified slightly and could be shed in ovo. From the basal layer Various suprabasal epithelial layers were produced. The first layer contained keratohyalin-like granules and was identified as a clear layer. Beneath it a spinulated (Anolis) or serrated (Podarcis) oberhautchen differentiated. The clear and 'oberhautchen' layers constitute the first shedding complex. The first epidermal layers that were shed consisted of flaking periderm or periderm together with the clear layer. The differentiation of a mesos layer was under way before hatching, when the epidermal morphology resembled a stage 4-5 of the adult shedding cycle. Fibroblasts under the inner side of the scale made few contacts with the basement membrane and their cytoplasmic elongations were mostly oriented parallel to the dense lamina. Instead, fibroblasts under the basal layer of the outer scale surface (BLOS) made numerous contacts with the basement membrane, suggesting that more dermal-epidermal interactions take place on this side of the scale.