灰飞虱体内WO噬菌体和Wolbachia的侵染关系

Relationship of WO phage and Wolbachia infection in Laodelphax striatellus(Fallén)(Hemiptera:Delphacidae)

WO噬菌体是侵染节肢动物体内感染的Wolbachia的细菌病毒,人们推测WO噬菌体可能参与了寄主遗传变异的过程。我们对采自中国境内4个地理种群（上海闵行、云南普洱、山东济宁和宁夏青铜峡）的灰飞虱Laodelphaxstriatellus1~2龄若虫用抗生素HCl-tetracycline处理过的水稻饲养,每隔20d取样测定并比较其体内Wolbachia和WO噬菌体的感染率,以此来初步研究灰飞虱体内WO噬菌体与Wolbachia的侵染关系,结果表明：WO噬菌体感染率的变化趋势与其宿主Wolbachia的基本一致,都随着时间推移逐步下降。我们进一步对未经HCl-tetracycline处理的灰飞虱,用实时定量PCR的方法对WO噬菌体和Wolbachia在不同日龄灰飞虱雌虫体内的菌量进行测定,结果显示,二者菌量都随着日龄的增长有所变化,在第8天达到最大,二者的变化趋势基本一致。由此我们推断WO噬菌体是侵染胞内共生菌Wolbachia的专性病毒,并且感染Wolbachia的WO噬菌体很可能是溶原性的噬菌体。

WO phage is the bacterial virus infecting Wolbachia in arthropods.It is supposed that WO phage may participate in controlling genetic changes of the hosts.Laodelphax striatellus planthoppers from four geographic populations of China（Minhang,Shanghai;Puer,Yunnan;Jining,Shandong;Qingtongxia,Ningxia）were bred on rice treated with antibiotics.The infection rates of Wolbachia and WO phage were examined every twenty days,and the infection relationships between Wolbachia and WO phage were analyzed based on the data obtained.The results revealed that the infection rate of Wolbachia declined with time,and so was WO phage.By using Real-time quantitative PCR,we found that the copy numbers of Wolbachia and WO phage varied with the developmental stages of adult female,displaying the highest quantity at 8 d post infection,and WO phage density showed the same pattern as that of Wolbachia.From the results,we inferred that WO phage is the obligate virus infecting Wolbachia,and the WO phage infecting Wolbachia in L.striatellus may be lysogenic.