Alibardi L, Edward D P, Patil L, Bouhenni R, Dhinojwala A, Niewiarowski P H
Department of Biology, University of Bologna, Italy.
J Morphol. 2011 Jun;272(6):758-68. doi: 10.1002/jmor.10948. Epub 2011 Apr 6.
We studied the distribution of lipid material and organelles in the epidermal layers of toe pads from two species of lizards representing the two main lizard families in which adhesive scansors are found (gekkonids and polychrotids), the dull day gecko, Phelsuma dubia and the green anole, Anolis carolinensis. Although lipids are a conspicuous component of the mesos layer of squamate reptiles and function in reducing cutaneous water loss, their distribution has not been specifically studied in the highly elaborated epidermal surface of adhesive toe pads. We found that, in addition to the typical cutaneous water loss-resistant mesos and alpha-layer lipids, the Oberhutchen (including the setae) on the most exterior layers of the epidermis in P. dubia and A. carolinensis also contain lipid material. We also present detailed histochemical and ultrastructural analyses of the toe pads of P. dubia, which indicate that lipid material is closely associated spatially with maturing setae as they branch during the renewal phase of epidermal regeneration. This lipid material appears associated with the packing of keratin within setae, possibly affecting permeability to water loss in the pad lamella, where the surface area is from 4–60-fold greater compared with normal scales.
我们研究了两种蜥蜴趾垫表皮层中脂质物质和细胞器的分布情况，这两种蜥蜴分别代表了发现有粘附扫描器的两个主要蜥蜴科（壁虎科和变色蜥科），即钝尾日行壁虎（Phelsuma dubia）和绿安乐蜥（Anolis carolinensis）。尽管脂质是有鳞目爬行动物中层的显著组成部分，且具有减少皮肤水分流失的功能，但其在高度特化的粘附趾垫表皮表面的分布尚未得到专门研究。我们发现，除了典型的具有抗皮肤水分流失功能的中层和α层脂质外，钝尾日行壁虎和绿安乐蜥表皮最外层的 Oberhutchen（包括刚毛）也含有脂质物质。我们还对钝尾日行壁虎的趾垫进行了详细的组织化学和超微结构分析，结果表明，在表皮再生更新阶段，脂质物质在空间上与成熟的刚毛密切相关，此时刚毛会分枝。这种脂质物质似乎与刚毛内角蛋白的堆积有关，可能会影响趾垫薄片的水分流失渗透性，其表面积比正常鳞片大4至60倍。
