文昌鱼精子发生的核孔复合体冷冻蚀刻电镜观察

OBSERVATION OF NUCLEAR PORE COMPLEX ON SPERMATOGENESIS OF AMPHIOXUS(BRANCHIOSTOMA BELCHERI GRAY) WITH FREEZE-ETCHING

1994-1996年每年3月、7月在厦门同安琼头海域采集雄性文昌鱼,采用冷冻蚀刻的常规技术,研究文昌鱼精子发生核孔复合体的变化规律。结果表明,在核孔复合体结构中很可能存在着作为运输物质的中央颗粒。各种生殖细胞中的核孔复合体的大小和密度不同,平均值约为:精原细胞（60±1.20）nm,（2.9±0.04）孔／μm2;初级精母细胞（76±1.80）nm,（4.8±0.05）孔／μm2;次级精母细胞（72±1.30）nm,（4.6±0.03）孔／μm2;精细胞（97±1.40）nm,（5.4±0.06）孔／μm2。这与细胞的生理功能有关。核孔复合体的分布具有明显的极性特点,主要集中在靠初级精母细胞的高尔基区一侧和靠精细胞的前项体一侧的核膜上,表明了细胞核局部的功能差异。

This research work was undertaken from Mar., 1994 to Sep., 1996 in Xiamen with the Branchiostoma belcheri Gray obtained from the sea area of Qongtou, Tongan, Xiamen every Mar.and July. The nuclear pore complex was studed in spermatogenesis of amphioxus (Branchiostoma belcheri Gray) with freeze-etching of electron microscope. The procedures are as follows. The amphioxus was fixed by 2.5%gluaradehyde for 2 hours, washed by buffer, immersed in 30% glucerine physiological saline, stored in refrigerator for 12-24 hours; then the sexual grand was taken out,fast frozen in liquld nitrogen (- 196℃), splited by BAF-400D freezing etcher (-110℃,2.67 × 10-3 Pa), sprayed with platinum and carbon, and observed by TEM. The results show that the cenha granu1es which are probaby associared with the trallsPOrt of marerial may or may not exist in the nuclear pore complex structure. The size and density of the nuclear pore complex in different reproductive cells are different, which is apparently concerned with the physiological fanction of the cells. The average diameter of nuclear pore complex of spermatogonium, primary spermatocyte, secondary spermatocyte and spermatid are (60±1.20)nm, (76±1.80)nm, (72 ±1.30)nm,(97±1.40)nm, respectively. The average density of nuclear pore complex of spermatogonium,primary spermatocyte, secondary spermatocyte, spermatid are (2.9 ±0.04) pore / μm2, (4.8 ±0.05) pore / μm2,(4.6 ±0.03) pore / μm2, (5.4 ±0.06) pore / μm2, respectively. The nuclear pore complex is centralized on one side of the nuclear membrane, close to the Golgi zone of the primary spermatocyte and the front acrosome of the spermatid, appearing in an obvious polar arrangement,this shows the difference in the function of different parts of the nucleus.