Department of Animal Histology and Embryology, Silesian University, 9 Bankowa Str., 40-007 Katowice, Poland.
Zoology (Jena). 2012 Dec;115(6):389-97. doi: 10.1016/j.zool.2012.07.001. Epub 2012 Oct 3.
The mechanism of follicular lumen differentiation during thyroid gland morphogenesis in vertebrate classes is still unclear and the current knowledge regarding the origin and the mechanism of follicular lumen formation during thyroid differentiation in reptiles is especially poor. The present study reports on an ultrastructural investigation of thyroid follicle formation and follicular lumen differentiation in grass snake (Natrix natrix L.) embryos. The results of this study show that the earliest morphogenesis of the presumptive thyroid follicles in grass snake embryos appears to be similar to that described in embryos of other vertebrate classes; however, differences appeared during the later stages of its differentiation when the follicular lumen was formed. The follicular lumen in grass snake embryos was differentiated by cavitation; during thyroid follicle formation, a population of centrally located cells was cleared through apoptosis to form the lumen. This manner of follicular lumen differentiation indicates that it has an extracellular origin. It cannot be excluded that other types of programmed cell death also occur during follicular lumen formation in this snake species.
在脊椎动物类中，甲状腺形态发生过程中滤泡腔分化的机制仍不清楚，而有关爬行动物中甲状腺分化过程中滤泡腔形成的起源和机制的知识尤其缺乏。本研究报告了对草蛇（Natrix natrix L.）胚胎中甲状腺滤泡形成和滤泡腔分化的超微结构研究。本研究结果表明，草蛇胚胎中假定的甲状腺滤泡的最早形态发生似乎与其他脊椎动物胚胎中描述的相似；然而，在分化后期形成滤泡腔时，出现了差异。草蛇胚胎中的滤泡腔通过空泡化进行分化；在甲状腺滤泡形成过程中，通过细胞凋亡清除中央位置的细胞群以形成腔。这种滤泡腔分化方式表明它具有细胞外起源。不能排除在这种蛇种的滤泡腔形成过程中还发生其他类型的程序性细胞死亡。
