DNA was not well-distributed in DFC and the fibres of rDNA were distributed in the form of a wheel spoke next to the edge of the FC.

• DFC中rDNA纤维分布不均匀,成束的rDNA纤维放射状分布于球形体FC周围,核仁次级FC和次级DFC的衍生过程发生在靠近FC和DFC中的DNA组分中,DFC中的rDNA组分随细胞周期的进行不断增多。