螅状独缩虫表膜下纤毛系及形态发生

INFRACILIATURE AND MORPHOGENESIS OF CARCHESIUM POLYPINUM (CILIOPHORA: PERITRICHIDA)

利用蛋白银技术研究了螅状独缩虫无性生殖周期中的形态发生。结果表明 :(1)在大核形态尚未出现明显变化时 ,生发毛基索 (GK)的前端即出现原基 ,随后原基增生扩大。最早出现的是两条将来分别演化为新仔虫第三咽膜 (P′3)和第二咽膜 (P′2 )的原基带 ,随后出现的是位于外侧的新仔虫的单毛基索 (HK′)。同时 ,新仔虫的第一咽膜 (P′1)也开始由老单毛基索 (HK)复制 ,并在细胞分裂后期与老结构分离 ;(2 )大核在虫体分裂过程中由长带状逐渐缩短变粗至扁圆形 ,于虫体即将分开时迅速拉长 ,然后分裂为二个新大核 ;小核分裂先于大核 ,在两仔虫口纤毛器即将分开时完成 ;(3)原帚胚及柄归属老仔虫 ,新仔虫的帚胚在虫体分裂后逐渐形成 ,柄内肌丝则在柄鞘形成后逐渐长出。

Infraciliature and morphogenesis of Carchesium polypinum during asexual cycle were studied with protargol technique. The results show: (1) Before the obviousty changed to the macronucleus in morphology, the germinal field for new buccal ciliary organelles became being with the kinetosomes in the front of the germinal row proliferating. With the development of the kinetosomes within the field, the peniculus 2 and 3 are formed, later the new haplokinety appeared, while the old haplokinety generated or duplicated the new peniculus 1 Both the new peniculus 1 and the old haplokinety separated at the telophase. The two germinal rows (GK′) for both the daughter cells appeared almost at the same time; (2) The macronucleus became shorter and thicker, finally oblate during the division of the cell. Then the macronucleus restored its original shape, band like form. The micronucleus were divided into two before the macronucleus division; (3) The original scopula and stalk contributed to the old cell. The new cell formed scopula gradually after the cell division. [FQ(2。46,X-W] * This work was supported by the National Natural Sciences Fundation of China (No. 39730070)