扬子鳄胚胎舌表面的扫描电镜观察

SCANNING ELECTRON MICROSCOPIC OBSERVATIONS ON THE SURFACE OF EMBRYONIC TONGUE OF ALLIGATOR SINENSIS

在扫描电镜下观察了孵化第３６ｄ至第６２ｄ孵出的扬子鳄（Ａｌｌｉｇａｔｏｒｓｉｎｅｎｓｉｓ）胚胎舌表面的形态变化过程。舌表面于孵化第３８ｄ形成少数大的隆起与凹陷，第４刚开始出现舌乳头。舌上皮细胞的表面在第３６～４２ｄ为圆形，表面光滑，中央凹陷，以后逐渐变成扁平细胞，第５２ｄ细胞呈规则的多边形，表面微绒毛清晰，细胞中央有一向外隆起的圆形或卵圆形核区，第５６ｄ后老化的舌上皮出现脱落现象。孵化第４２ｄ舌后部及中部的上皮内陷形成较大的舌腺腺孔。第４８～５６ｄ中，较小的舌腺孔显著增多，而大舌腺孔数目无明显增加。第６２ｄ多数大舌腺孔内可见有粘液样分泌物。舌表面味蕾的形成很迟，第５６ｄ才出现Ⅰ、Ⅱ、Ⅲ型发育中的味蕾，第６２ｄ形成部分成熟的味蕾。本文对扬子鳄舌腺及味蕾的形态发生特点作了讨论。

The morphogenesis of the tongue surface of Alligator sinensis embryos from 36th to 62nd day of incubation was investigated by means of scanning electron microscopy.A few of large swellings and invaginations formed in the tongue surface at 38th day of incubation,and the lingual papillae appeared at 48th day of incubation.The surface of lingual epithelial cells was smooth and rounded with a central pit during 36-42nd days of incubation,and became flattened afterwards.At 52nd day of incubation,the surface of lingual epithelial cells appeared as polygon-shaped with evident microvilli and a round orovoid nucleus swelling at the central.After 56th day of incubation,the degeneration of old lingual epithelium was observed.At 4 2 nd day of incubation, the epithelium at the posterior and central part of the tongue invaginated to form large holes of glandula lingualis.During 4 8-56th days of incubation,small holes of glandula lingualis increased continuously but large holes kept nearly unchanged.Mucuslike substance was found in many large glandular holes at 62nd day of incubation. The taste bud formation on the tongue surface was very late. The developing taste buds of type l,2,3 appeared at 56th day of incubation ,and some mature taste buds formed at 62nd day of incubation. This paper discussed the morphogenetic characteristics of glandula lingualis and taste bud of Alligator sinensis.