脊椎动物皮肤是支持和保护身体的重要器官。它由两层组成,表皮和下面的真皮。在一些四足动物中,真皮包括被称为骨胚层(OD)的矿化器官。蜥蜴,有7000多个物种,在OD形态和分布上表现出最大的多样性,然而,我们几乎不明白是什么推动了这种多样性。对五种蜥蜴的多尺度分析,他们的血统在100-1.5亿年前分歧,比较微观和宏观结构,材料属性,和ODs的弯曲刚度,并检查了颅骨屋顶和颌骨的下层骨骼(包括可能的牙齿)。毫不奇怪,OD形状,独自一人,影响弯曲刚度,斑马的ODs最灵活,TimonLepidus的ODs最刚性。宏观的变化也反映在微观结构的多样性,组织组成和排列的差异。然而,核心骨组织的特性,在ODS和颅骨中,被发现在不同的类群中相似,虽然艰难,Heloderma和Pseudopus的OD上的盖帽组织具有与牙釉质相似的材料特性。结果为颅骨ODs的功能适应提供了证据,但是关于推动其多样性的因素仍然存在疑问。重要性声明:理解自然一直是物理和生物科学各个领域的重要灵感来源。在这里,我们解开了一个新的生物矿化,即钙化组织,OD,在蜥蜴的皮肤内形成,在整个群体中表现出显著的多样性。使用了一系列技术来深入了解这些异常多样的自然结构,在一个综合的,整个系统的时尚。我们的结果为OD及其层次结构的功能和生物力学适应提供了一些建议。这些知识可以为仿生和生物灵感设计提供潜在的灵感来源,适用于轻质制造,组织工程等领域的损伤耐受性和多功能材料。
Vertebrate skin is a remarkable organ that supports and protects the body. It consists of two layers, the epidermis and the underlying dermis. In some tetrapods, the dermis includes mineralised organs known as osteoderms (OD). Lizards, with over 7,000 species, show the greatest diversity in OD morphology and distribution, yet we barely understand what drives this diversity. This multiscale analysis of five species of lizards, whose lineages diverged ∼100-150 million years ago, compared the micro- and macrostructure, material properties, and bending rigidity of their ODs, and examined the underlying bones of the skull roof and jaw (including teeth when possible). Unsurprisingly, OD shape, taken alone, impacts bending rigidity, with the ODs of Corucia zebrata being most flexible and those of Timon lepidus being most rigid. Macroscopic variation is also reflected in microstructural diversity, with differences in tissue composition and arrangement. However, the properties of the core bony tissues, in both ODs and cranial bones, were found to be similar across taxa, although the hard, capping tissue on the ODs of Heloderma and Pseudopus had material properties similar to those of tooth enamel. The results offer evidence on the functional adaptations of cranial ODs, but questions remain regarding the factors driving their diversity. STATEMENT OF SIGNIFICANCE: Understanding nature has always been a significant source of inspiration for various areas of the physical and biological sciences. Here we unravelled a novel biomineralization, i.e. calcified tissue, OD, forming within the skin of lizards which show significant diversity across the group. A range of techniques were used to provide an insight into these exceptionally diverse natural structures, in an integrated, whole system fashion. Our results offer some suggestions into the functional and biomechanical adaptations of OD and their hierarchical structure. This knowledge can provide a potential source of inspiration for biomimetic and bioinspired designs, applicable to the manufacturing of light-weight, damage-tolerant and multifunctional materials for areas such as tissue engineering.