中华大蟾蜍蝌蚪变态过程中脊椎骨化次序

两栖动物在幼体变态即由水栖到陆栖的环境转变中,骨骼系统会发生重塑。本文采用茜素红和阿利新蓝的双染色技术对不同发育阶段中华大蟾蜍(Bufo gargarizans)蝌蚪变态过程中(Gosner 38~46)脊椎骨的发育进程进行了形态学研究。结果显示,在中华大蟾蜍蝌蚪Gosner 39期,椎板中线处发生融合;荐前椎Ⅱ-Ⅷ和荐椎的椎体、椎弓起始骨化发生在Gosner 42期;其次荐前椎Ⅱ-Ⅷ和荐椎的横突、底索和荐后椎Ⅰ开始骨化;荐后椎Ⅱ骨化最晚;在Gosner 46期,尾杆骨最终形成。荐后椎愈合形成尾杆骨反映无尾类幼体由水栖环境转变为陆生环境中骨骼系统的机能适应。

Ossification Sequence of the Vertebrae during Metamorphosis of Bufo gargarizans Tadpoles

Skeletal system remodeling of tadpoles, which occurs during amphibian metamorphosis, adapt to the change from aquatic habitat to land habitat. In this study, the vertebrae skeletons of Bufo gargarizans tadpole during different stages were investigated using double stained. The results regarding B. gargarizans as follows: the centra and neural arch of atlas-postsacrals started to ossify at Gosner stage 42, then the transverse processes of atlas-sacrum, hypochord, Postsacral I and Postsacral II began to ossify; finally the urostyle formed at Gosner stage 46. More postsacral occurred in the larval development of anuran suggested that species is primitive. By contrast, less postsacral suggested that the species is advanced.