中国林蛙变态发育中舌鳃骨的形态变化

Morphological changes of hyobranchial skeleton in the metamorphosis of Rana chensinensis

为揭示中国林蛙(Rana chensinensis)蝌蚪变态发育中舌鳃骨的形态变化,采用改良的Toyal骨骼双染色法对Gosner(G)26~46期中国林蛙蝌蚪舌鳃骨进行染色,并观察、比较和采集图像。结果显示,中国林蛙蝌蚪的舌鳃骨由角舌骨、关联骨、鳃下骨板和鳃篮4部分构成。在变态发育中,舌鳃骨始终以软骨状态存在。G26期蝌蚪的舌鳃骨已具备完整结构,G26~G38期舌鳃骨各部分呈等速率生长,至G38期舌鳃骨达到最大;G39~G41期舌鳃骨开始自行吸收,形态略变小;G42期舌鳃骨形态已有较大变化;G43~G46期舌鳃骨的角舌骨、关联骨和鳃下骨板均发生变形与重塑,鳃篮逐渐消失,舌鳃骨发育为成体舌骨。为了适应生理功能的变化,中国林蛙蝌蚪舌鳃骨的形态结构经历了由小到大、又由大变小、最终在舌鳃骨原来位置重塑出成体舌骨的发育过程。

In order to reveal the morphological changes of hyobranchial skeleton in the metamorphosis of Rana chensinensis tadpoles,modified Toyal bone double staining method was used to stain the hyobranchial skeleton of Rana chensinensis tadpoles from Gosner(G)26 to 46 stages for the observation,comparison and image collection of hyobranchial skeleton.The results showed that the hyobranchial skeleton of Rana chensinensis tadpoles was composed of 4 parts,including ceratohyal,copula,hyobranchial plate and branchial basket,and always existed in the condition of cartilage during metamorphosis.The hyobranchial skeleton of tadpoles had complete structures at G26 stage,then all parts of the hyobranchial skeleton grew at the same rate during G26 and G38 stages,and reached the largest at G38 stage.During G39 and G41 stages,hyobranchial skeleton began to absorb and turn smaller with obvious variation observed at G42 stage.From G43 to G46 stages,the ceratohyal,copula and hyobranchial plate deformed and reshaped,the branchial basket gradually disappeared,and the hyobranchial skeleton developed into adult hyoid bone.To adapt the changes of physiological function,the hyobranchial skeleton of Rana chensinensis tadpoles suffers small-big-small development and finally becomes adult hyoid bone.