Ultrastructural Localization of Hair Keratin Homologs in the Claw of the Lizard Anolis carolinensis
Ultrastructural Localization of Hair Keratin Homologs in the Claw of the Lizard Anolis carolinensis
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DOI：
10.1002/jmor.10920
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发表时间：
2011-03-01
影响因子：
1.5
通讯作者：
Eckhart, Leopold
中科院分区：
文献类型：
--
作者：
Alibardi, Lorenzo;Jaeger, Karin;Eckhart, Leopold
蜥蜴的爪子主要由β-角蛋白组成，也称为角蛋白相关β-蛋白。最近，我们报道了蜥蜴Anolis carolinensis的基因组含有与哺乳动物的毛发和爪典型的毛发角蛋白同源的α角蛋白基因。分子生物学和免疫组织化学研究表明，两种毛发角蛋白同源物，即硬酸性角蛋白1（HA 1）和硬碱性角蛋白1（HB 1），在形成A. carolinensis。在这里，我们扩展了免疫细胞化学定位的新型爬行动物角蛋白的超微结构水平。切片后，使用针对HA1、HB1的抗体和用于比较的β-角蛋白对爪进行免疫金标记。电子显微镜显示，在基底和基底上角质形成细胞的张力细丝的随机组织的网络变得有组织的长和平行束的角蛋白在前角质层，类似皮质细胞的头发。进入爪子的角质化部分，细长的角质细胞融合并积累角质物质。HA1和HB1在爪的基底层和下棘肌层中不存在，并且在上和前角质层中表达，包括伸长的角质细胞。α-角蛋白的标记与形成爪的纤维框架的细丝结构松散相关。硬α-角蛋白的超微结构分布模式类似于β-角蛋白，这与爪形态发生过程中相互作用的假设是一致的。毛角蛋白同系物的超微结构定位的数据有利于蜥蜴爪和哺乳动物的硬表皮附属物含有毛角蛋白的比较。J. Morphol. 272：363 - 370，2011。(C)2010 Wiley-Liss，Inc.
The claw of lizards is largely composed of beta-keratins, also referred to as keratin-associated beta-proteins. Recently, we have reported that the genome of the lizard Anolis carolinensis contains alpha keratin genes homologous to hair keratins typical of hairs and claws of mammals. Molecular and immunohistochemical studies demonstrated that two hair keratin homologs named hard acid keratin 1 (HA1) and hard basic keratin 1 (HB1) are expressed in keratinocytes forming the claws of A. carolinensis. Here, we extended the immunocytochemical localization of the novel reptilian keratins to the ultrastructural level. After sectioning, claws were subjected to immunogold labeling using antibodies against HA1, HB1, and, for comparison, beta-keratins. Electron microscopy showed that the randomly organized network of tonofilaments in basal and suprabasal keratinocytes becomes organized in long and parallel bundles of keratin in precorneous layers, resembling cortical cells of hairs. Entering the cornified part of the claw, the elongated corneous cells fuse and accumulate corneous material. HA1 and HB1 are absent in the basal layer and lower spinosus layers of the claw and are expressed in the upper and precorneous layers, including the elongating corneocytes. The labeling for alpha-keratin was loosely associated with filament structures forming the fibrous framework of the claws. The ultrastructural distribution pattern of hard alpha-keratins resembled that of beta-keratins, which is compatible with the hypothesis of an interaction during claw morphogenesis. The data on the ultrastructural localization of hair keratin homologs facilitate a comparison of lizard claws and mammalian hard epidermal appendages containing hair keratins. J. Morphol. 272: 363-370, 2011. (C) 2010 Wiley-Liss, Inc.