家蚕微孢子虫(Nosema bombycis)侵染草地贪夜蛾卵巢细胞(Sf21)体系的建立

Establishing of the Infected System of Nosema bombycis in Sf21 Cell Line

家蚕微孢子虫(Nosemabombycis,简称N.b)经KOH处理后,接种于草地贪夜蛾卵巢细胞(Sf21),建立家蚕微孢子感染增殖体系,同时,对孢子与宿主细胞在感染增殖过程中的形态变化进行了跟踪观察。KOH处理的孢子发芽率约为67%,Sf21细胞的初期感染率约为4.3%,接种24h内,细胞感染率变化不明显,但随后逐渐增加,到接种后的第7天达76.9%。接种后第12天起,细胞内充满不同发育阶段的孢子,并可见大量的胞外游动孢子。随后,大量细胞破裂,孢子逸出后,破裂的细胞内出现大量囊泡,且有合胞体(巨型多核融合细胞)出现。另外,将感染孢子的家蚕中肠组织和丝腺组织用胰蛋白酶处理后直接接种Sf21细胞,不经发芽处理,细胞也能感染。

Spores of Nosema bombycis were treated with 0.2 mol/L KOH solution and then inoculated in Sf21 cell line, the infected system of Nosema bombycis in Sf21 Cell line was established.Propagation of Nosema bombycis was observed in Sf21 cell line. The percentage of hatched spores was 67%.The infection rate in Sf21 cell line was within 12 hr 4 3%,then increased gradually, and reached 76 9% on the seventh day. On twelfth day, a lot of mature spores of N.b were found outside the infected cells. At the same time, a mass of cells broke, and the phenomenon of saccate vacuoles and cells-fusion were present. In addition, the midgut and silk gland collected from infected silkworms and treated by 0.25% trypsin were directly inoculated in Sf21 cell line,infection was observed.