advanced bell stage的用法和样例：
- At the bell stage, immunoreactive bFGF was localized to the preameloblasts.
- Objective: To study expression of whether Shh and its receptor Ptc during late bell stage in mouse tooth germ.
目的 :判断sonichedgehog(Shh)基因及其受体patched(Ptc)是否在小鼠牙胚钟状晚期有表达。 方法 :用RT PCR法研究Shh及其受体Ptc在小鼠牙胚钟状晚期的表达。
- Shh and its receptor are expressed during the late bell stage of mouse tooth germ.
- Results: The expression was significant in the proliferating growth center of the bud ,the cap and earlier bell stage of tooth development.