Bonfitto A, Randi R, Ciubotaru M, Alibardi L
Department of Biological, Geological and Environmental Sciences (BiGeA), University of Bologna, Via Selmi 3, 40126, Bologna, Italy.
, Trequanda, Siena, Italy.
Protoplasma. 2025 Jul;262(4):935-955. doi: 10.1007/s00709-025-02040-6. Epub 2025 Feb 10.
The present study conducted using immunofluorescence, scanning electron microscopy, and transmission electron microscopy aims to determine the origin of the lamellated pattern and of the micro-ornamentation formed in tail scales of the lacertid lizard Podarcis muralis. Regenerating scales shows the typical formation of all the epidermal layers of lizard epidermis, including clear and Oberhautchen layers. The latter initiates the accumulation of hard corneous material containing corneous beta proteins (CBPs) that determine a tension with the overlaying softer clear layer containing mainly intermediate filaments of keratins (IFKs). The two layers, initially joined by numerous desmosomes, are later displaced one from the other with the growth of regenerating scales, forming a slanted surface as observed under transmission electron microscopy (TEM). At the beginning of scale regeneration, the slanted tips form an irregular lamellated pattern on the surface of Oberhautchen cells, appearing as crests or waves under scanning electron microscopy (SEM). In the following scale differentiation, growth, and shedding of molt, the irregular crests form a more ordered and parallel microsculptured and micro-ornamentation pattern when Oberhautchen and beta-cells merge one to another and give rise to a mature beta-layer. Hard CBP-based corneous material and electron-dense materials of unknown composition together with IFKs are accumulated in the slanted surface of the differentiating Oberhautchen cells. During scale growth, the Oberhautchen surface matures into a jig-saw outline that gives rise to the lamellated pattern of mature micro-ornamentation. The study suggests that complex micro-ornamentation patterns in other lizard species can also vary during scale formation, in development, growth, or regeneration.
本研究采用免疫荧光、扫描电子显微镜和透射电子显微镜,旨在确定蜥蜴Podarcis muralis尾鳞中形成的层状图案和微纹饰的起源。再生鳞片显示出蜥蜴表皮所有表皮层的典型形成过程,包括透明层和上表皮层。后者引发了含有角质β蛋白(CBPs)的硬角质物质的积累,这些物质与覆盖其上的主要含有角蛋白中间丝(IFKs)的较软透明层产生张力。这两层最初通过大量桥粒连接,随后随着再生鳞片的生长而相互移位,如在透射电子显微镜(TEM)下观察到的那样形成一个倾斜表面。在鳞片再生开始时,倾斜的尖端在Oberhautchen细胞表面形成不规则的层状图案,在扫描电子显微镜(SEM)下呈现为嵴或波浪状。在随后的鳞片分化、生长和蜕皮脱落过程中,当Oberhautchen细胞和β细胞相互融合并形成成熟的β层时,不规则的嵴形成了更有序和平行的微雕刻和微纹饰图案。基于硬CBP的角质物质和成分未知的电子致密物质以及IFKs在分化的Oberhautchen细胞的倾斜表面积累。在鳞片生长过程中,Oberhautchen表面成熟为拼图轮廓,从而产生成熟微纹饰的层状图案。该研究表明,其他蜥蜴物种的复杂微纹饰图案在鳞片形成、发育、生长或再生过程中也可能有所不同。