Cilia containing 9+2 structures grown from immortalized cells

Cilia depend on their highly differentiated structure, a 9 ＋ 2 arrangement, to remove particles from the lung and to transport reproductive cells. Immortalized cells could potentially be of great use in cilia research. Immortalization of cells with cilia structure containing the 9 ＋ 2 arrangement might be able to generate cell lines with such cilia structure. How- ever, whether immortalized cells can retain such a highly differentiated structure remains unclear. Here we demonstrate that （1） using Ela gene transfection, tracheal cells are immortalized; （2） interestingly, in a gel culture the immortalized cells form spherical aggregations within which a lumen is developed; and （3） surprisingly, inside the aggregation, cilia containing a 9 ＋ 2 arrangement grow from the cell＇s apical pole and protrude into the lumen. These results may influence future research in many areas such as understanding the mechanisms of cilia differentiation, cilia generation in other existing cell lines, cilia disorders, generation of other highly differentiated structures besides cilia using the gel culture, immortalization of other ciliated cells with the Ela gene, development of cilia motile function, and establishment of a research model to provide uniform ciliated cells.

史氏鲟精子超微结构

利用扫描和透射电镜观察了史氏鲟精子形态和超微结构。精子具有顶体、头部、中段和单鞭毛等部分。顶体长0.99±0.06μm,宽0.87±0.09μm。细胞核从后往前逐渐变细,前端宽度为0.88±0.04μm,后端宽度为1.26±0.06μm,细胞核长7.29±0.32μm。核内含有3条核管（E）,核管上行至顶体下行至植入窝而止。中段紧接头后部,长为0.51±0.12μm,宽0.91±0.05μm。中段含有线粒体、中心粒复合体和鞭毛的起始部分。线粒体分2~3层排列,线粒体中可见髓样嵴结构。在细胞核与中段接合部细胞核向内凹陷形成植入窝,纤维体位于植入窝内,其后是中心粒复合体。中段后缘延长为袖套,袖套腔中含有线粒体、脂质空泡。鞭毛从袖套中伸出,由轴丝组成,为典型的“9＋2”微管结构。