Rentrop M, Knapp B, Winter H, Schweizer J
J Cell Biol. 1986 Dec;103(6 Pt 2):2583-91. doi: 10.1083/jcb.103.6.2583.
The tongue of the adult mouse is covered by a multilayered squamous epithelium which is continuous on the ventral surface, however interrupted on the dorsal surface by many filiform and few fungiform papillae. The filiform papillae themselves are subdivided into an anterior and posterior unit exhibiting different forms of keratinization. Thus, the entire epithelium shows a pronounced morphological diversity of well recognizable tissue units. We have used a highly sensitive in situ hybridization technique to investigate the differential expression of keratin mRNAs in the tongue epithelium. The hybridization probes used were cDNA restriction fragments complementary to the most specific 3'-regions of any given keratin mRNA. We could show that independent of the morphologically different tongue regions, all basal cells uniformly express the mRNA of a type I 52-kD keratin, typical also for basal cells of the epidermis. Immediately above the homogenous basal layer a vertically oriented specialization of the keratin expression occurs within the morphological tissue units. Thus the dorsal interpapillary and ventral epithelium express the mRNAs of a type II 57-kD and a type I 47-kD keratin pair. In contrast, in the anterior unit of the filiform papillae, only the 47-kD mRNA is present, indicating that this keratin may be coexpressed in tongue epithelium with different type II partners. In suprabasal cells of both, the fungiform papillae and the posterior unit of the filiform papillae, a mRNA of a type I 59-kD keratin could be detected; however, its type II 67-kD epidermal counterpart seems not to be present in these cells. Most surprisingly, in distinct cells of both types of papillae, a type I 50-kD keratin mRNA could be localized which usually is associated with epidermal hyperproliferation. In conclusion, the in situ hybridization technique applied has been proved to be a powerful method for detailed studies of differentiation processes, especially in morphologically complex epithelia.
成年小鼠的舌头表面覆盖着多层鳞状上皮，腹侧表面的上皮是连续的，但背侧表面被许多丝状乳头和少量菌状乳头中断。丝状乳头本身又分为前部和后部，呈现出不同形式的角质化。因此，整个上皮显示出明显的形态多样性，组织单位易于识别。我们使用了一种高度敏感的原位杂交技术来研究角蛋白mRNA在舌上皮中的差异表达。所用的杂交探针是与任何给定角蛋白mRNA最特异的3'区域互补的cDNA限制性片段。我们可以证明，与形态不同的舌区无关，所有基底细胞均一致表达一种I型52-kD角蛋白的mRNA，这也是表皮基底细胞的典型特征。在均匀的基底层上方，形态学组织单位内会出现角蛋白表达的垂直特化。因此，背侧乳头间上皮和腹侧上皮表达II型57-kD和I型47-kD角蛋白对的mRNA。相比之下，在丝状乳头的前部单位中，仅存在47-kD mRNA，这表明该角蛋白可能在舌上皮中与不同的II型伴侣共表达。在菌状乳头和丝状乳头后部单位的基底上层细胞中，均可检测到I型59-kD角蛋白的mRNA；然而，其II型67-kD的表皮对应物似乎在这些细胞中不存在。最令人惊讶的是，在两种乳头的不同细胞中，均可定位到I型50-kD角蛋白mRNA，该角蛋白通常与表皮过度增殖相关。总之，所应用的原位杂交技术已被证明是详细研究分化过程的有力方法，尤其是在形态复杂的上皮组织中。
