Nucleolus is mainly consisted of FC, DFC and GC. It is found in the cells of animal and plant and yeast and there is more than one nucleolus in one nucleus.

• 核仁主要由FC (fibrillar center)和DFC (dense fibrillar component)以及GC (granular component)等超微结构组成,普遍存在于动物细胞,植物细胞和酵母细胞核中。