Department of Animal Histology and Embryology, Silesian University, 9 Bankowa Str., 40-007 Katowice, Poland.
Zoology (Jena). 2010 Dec;113(6):339-60. doi: 10.1016/j.zool.2010.07.002. Epub 2010 Nov 11.
The changes and biochemical features of the epidermis that accompany the differentiation and embryonic shedding complex formation in grass snake Natrix natrix L. embryos were studied ultrastructurally and immunocytochemically with two panels of antibodies (AE1, AE3, AE1/AE3; anti-cytokeratin, pan mixture, Lu-5 and PCK-26). All observed changes in the ultrastructure of the cells forming the epidermal layers were associated with the physiological changes that occurred in the embryonic epidermis, such as changing of the manner of nutrition and keratinization leading to the embryonic shedding complex formation. The layers that originated first (basal, outer and inner periderm and clear layer) differentiated very early and rapidly. Rapid differentiation was also observed in the layers that are very important for the functioning of the epidermis in Natrix embryos (oberhäutchen and beta-layers). They started to differentiate at developmental stage IX, and then fused and formed the embryonic shedding complex at developmental stage XI. During the embryonic development of the grass snake the smallest changes appeared in the ultrastructure of the cells in the mesos and alpha-layers because they perform supplementary functions in the process of embryonic molting. They were undifferentiated until the end of embryonic development and started to differentiate just before the first adult molting. AE1/AE3, anti-cytokeratin, pan mixture, Lu-5 and PCK-26 antibodies immunolabeled clear layer, oberhäutchen and beta-layers at the latest phase of developmental stage XI. It should be noted that these antibodies did not immunolabel the alpha-layer until hatching. The presence of alpha-keratin immunolabeling in layers that were keratinized, particularly in the oberhäutchen and beta-layers in embryos, indicated that they were not as hard as in fully mature individuals.
草蛇 Natrix natrix L. 胚胎表皮细胞在分化和胚胎蜕皮复合体形成过程中的超微结构和免疫细胞化学变化，使用两组抗体（AE1、AE3、AE1/AE3；抗细胞角蛋白、泛混合物、Lu-5 和 PCK-26）进行了研究。形成表皮层的细胞的所有观察到的超微结构变化都与胚胎表皮发生的生理变化有关，例如改变营养和角化方式，导致胚胎蜕皮复合体形成。首先起源的层（基底、外和内皮层和透明层）分化非常早且迅速。在 Natrix 胚胎表皮中非常重要的层（上皮和β层）也观察到快速分化。它们在发育阶段 IX 开始分化，然后在发育阶段 XI 融合形成胚胎蜕皮复合体。在草蛇胚胎发育过程中，中间层和α层细胞的超微结构变化最小，因为它们在胚胎蜕皮过程中发挥辅助功能。它们直到胚胎发育结束都没有分化，直到第一次成年蜕皮前才开始分化。AE1/AE3、抗细胞角蛋白、泛混合物、Lu-5 和 PCK-26 抗体在发育阶段 XI 的最晚阶段标记透明层、上皮和β层。值得注意的是，这些抗体直到孵化后才标记α层。在已角化的层中存在α-角蛋白免疫标记，特别是在胚胎的上皮和β层中，表明它们不如完全成熟个体坚硬。
