菜蛾盘绒茧蜂多分DNA病毒对寄主小菜蛾幼虫体内部分组织的影响

Effects of Cotesia plutellae Polydnaviruses on Partial Tissues of Host Plutella xylostella Larva

利用显微注射方法,观察了菜蛾盘绒茧蜂多分DNA病毒(CpBV)对其寄主小菜蛾幼虫部分组织的影响。结果表明,CpBV进入寄主体内后能够影响其精巢、前胸腺和中肠等的变化。当被注射CpBV后,寄主精巢体积的增长受到抑制,并且有被分解的现象;颜色也随之逐渐变淡,直至呈现透明。前胸腺大小在感染CpBV12h时就已经变小。中肠发育受阻,被分解,分布的气管出现萎缩现象,颜色由正常发育时的绿色变为黄色,个别会呈现红色,约20%中肠出现红色斑点。凝胶电泳分析表明,小菜蛾幼虫注射过CpBV后,其精巢、中肠和前胸腺中蛋白种类均减少,特别是精巢,仅有一条蛋白条带(78·8kD)较为清晰,蛋白条带明显变淡,说明蛋白含量明显下降;但前胸腺81·2kD的蛋白条带在感染CpBV后要比对照更为清晰。中肠酯酶活性测定表明,感染CpBV后中肠酯酶的活力受到抑制,酯酶活性减弱。

The effects of Cotesia plutellae polydnaviruses （CpBV） on larval tissues of host Plutella xylostella were evaluated. Microinjection and microscopy examination revealed that CpBVs affected the development of larval tissues, such as spermary, prothoracic gland and mid-gut. After infected by CpBVs, the spermary was suppressed in volume and eventually partially decomposed, its color became light gradually until transparent at the final stage; the prothoracic gland shrank after infected by CpBVs in 12 h; the midgut was also stunted, decomposed, its color was changed from green （normal） to yellow, some red spots appeared on midgut of partial individuals, and trachea on midgut shrank at the same time. SDS-PAGE analyses showed that there were a number of proteins in normal spermary, pmthoracic gland and mid-gut： nearly 20 protein bands from spermary with the 78.8 kD band most clear and 66.2, 43.4, 34.83, 30.0 and 28.58 kD protein bands relatively clear; more than 10 protein bands from midgut with 63.7 kD band most clear and 79.39, 54.7, 41. 1, 30.7 and 28.9 kD protein bands relatively clear; also more than 10 protein bands from prothoracic gland with 81.2 and 55.76 kD protein bands relatively clear. After infected by CpBVs, the numbers of proteins in above tree tissues decreased significantly, especially for spermary, only one band was visible; and all bands became paler, suggesting that the concentration of proteins decreased after infected by CpBVs. But one band （81.2 kD） from prothoracic gland was more clear than that from normal one, suggesting that its concentration increased after CpBV infection. The bioassay indicated that the esterase activity in midgut declined after infected by CpBV.