摘　要：由于环境污染以及人工捕杀等因素，野生黑斑蛙（Rana nigromaculata）的数量已远不能满足人们的需求，因此，人工驯食蛙养殖逐渐兴起。但是，要保证驯食蛙的产量，第一步就是解决食物的摄取问题。而舌头是一个重要的摄食和味觉器官，直接影响了其对食物的摄取与否。因此，本研究采用光学显微技术、扫描电子显微技术及透射电镜超微技术对野生黑斑蛙和驯食黑斑蛙的舌背表面及内部超微结构进行了研究。石蜡切片研究表明，野生黑斑蛙与驯食黑斑蛙二者都有角质化的丝状乳头和菌状乳头。丝状乳头分布在整个舌背表面，并由主乳头和次级乳头构成。菌状乳头呈圆形，位于舌尖和舌缘；去除上皮后，菌状乳头的上皮细胞呈火山状，顶部有一个味蕾腔。但二者在舌组织学结构上也存在一定的差异：野生黑斑蛙舌表面的丝状乳头相对更加发达，且角质化程度比驯食黑斑蛙更明显。通过扫描电镜超微结构的比较发现，在野生和驯食黑斑蛙中都可以观察到位于背表面尾部区域舌侧的大尺寸轮廓乳头，以及由上皮褶皱组成的叶状乳头，并由平行的凹槽分隔开。二者的舌组织扫描亚显微结构也存在一定的差异：野生黑斑蛙舌表面的丝状乳头更加发达，其角质化程度比驯食黑斑蛙更大，这与石蜡切片研究结果一致。通过透射电镜超微结构的比较观察发现，野生和驯食黑斑蛙的舌心由骨骼肌纤维、结缔组织和舌腺组成。肌纤维在三个平面上交叉，固有层和黏膜下层包含有血管和神经纤维, 周围环绕着薄的结缔组织纤维。唾液腺局限于舌的后部，由许多浆液细胞和黏液细胞组成。因此，可推测黑斑蛙舌组织结构与其摄食食物是密切相关的。本研究结果既丰富了黑斑蛙乃至两栖类动物舌组织学结构的研究，也为野生黑斑蛙种质资源保护、驯食黑斑蛙饲料配方的改良及其产业发展提供了试验依据。
关键词：野生黑斑蛙；驯食黑斑蛙；舌乳头；组织学；水产养殖
中图分类号：S966.3+2                         文献标志码：A                    DOI：10.3969/j.issn.1007-7146.2022.06.010

Abstract:  Due to environmental pollution and artificial hunting and other factors, the number of wild Rana nigromaculata has been far from meeting the needs of people, hence the artificial training of domesticated Rana nigromaculata is gradually emerging. Nevertheless, to ensure the production of domesticated Rana nigromaculata, the first step is to solve the food intake related problems. The tongue is an important feeding and taste organ, which directly affects its food intake function. In this study, optical microscopy, scanning electron microscopy and transmission electron microscopy were used to study the ultrastructure of the dorsal surface and interior of the tongue of wild and domesticated Rana nigromaculata. The paraffin section study showed that both wild and domesticated Rana nigromaculata had keratinized filamentous papillae and bacteriform papillae. Filamentous papillae were distributed throughout the dorsal surface of the tongue and were composed of primary and secondary papillae. The bacteriform papillae were round, located at the tip of tongue and tongue margin. When the epithelium was removed, the epithelium of the bacteriform papilla was volcanically shaped with a taste bud cavity at the top. However, there were some differences in the histological structure of the tongue: the filamentous papillae on the tongue surface of wild Rana nigromaculata are more developed, and the degree of keratinization was more obvious than that of domesticated Rana nigromaculata. By comparing the ultrastructure of scanning electron microscopy, it was found that both wild and domesticated Rana nigromaculata could be observeed that there were large size circumvallate papilla on the lingual side of the dorsal surface caudal region, and foliated papilla composed of epithelial folds separated by parallel grooves. There were some differences in the scanning submicrostructure of tongue tissue between the two species. The filamentous papillae on the tongue surface of wild Rana nigromaculata were more developed and the degree of keratinization was greater than that of domesticated Rana nigromaculata. This was consistemt with the results of paraffin section study. The comparative observation of ultrastructure by transmission electron microscopy showed that the tongue heart of wild and domesticated Rana nigromaculata was composed of skeletal muscle fibers, connective tissue and tongue glands. The muscle fibers crossed over in three planes. The lamina propria and submucosa contain blood vessels and nerve fibers and were surrounded by thin connective tissue fibers. The salivary glands were confined to the back of the tongue and consist of many serous and mucous cells. Therefore, it can be inferred that the tongue structure is closely related to its food intake. The results of this study not only can enrich the study of tongue histological structure of Rana nigromaculata and amphibians, but also provide experimental basis for the conservation of wild germplasm resources of Rana nigromaculata, the improvement of diet formula of domesticated Rana nigromaculata and the development of industrial production.
Key words: wild Rana nigromaculata; domesticated Rana nigromaculata; lingual papilla; histology; aquaculture
（Acta Laser Biology Sinica, 2022, 31(6): 550-558）