Wolbachia为节肢动物等的细胞质共生细菌,能对宿主的繁殖模式进行调控,包括诱导胞质不亲和、孤雌生殖、雌性化及雄性致死。本文采集了分布于美国的4种瘿蜂,利用Wolbachia的wsp基因特异性引物,对其Wolbachia的感染进行了PCR检测,证实了栎结瘤瘿蜂Callirhytis punctata Bassett和摇鼓栎瘿蜂Dryocosmus palustris Osten Sacken体内具Wolbachia共生,感染率分别为60%和36%。栎结瘤瘿蜂和摇鼓栎瘿蜂Wolbachia的wsp基因序列长度分别为564 bp和561 bp。 栎结瘤瘿蜂与摇鼓栎瘿蜂Wolbachia的wsp基因序列的一致性为94%。栎结瘤瘿蜂与同为栎瘿蜂族的Andricus solitarius (strain 1)和Neuroterus macropterus,及客瘿蜂族的Synergus crassicorni的Wolbachia的wsp基因序列完全一致,与其他瘿蜂Wolbachia的wsp基因的序列一致性介于79 -99%之间。在NJ系统发育树中,栎结瘤瘿蜂与栎瘿蜂族的A. solitaries (strain 1),N. macropterus和B. pallida,以及客瘿蜂族的S. crassicornis的Wolbachia同属一分支,而摇鼓栎瘿蜂与栎瘿蜂族的麦氏安瘿蜂的Wolbachia聚集在同一分支。除客瘿蜂族的Ceroptres cerri感染的Wolbachia属于B群之外,其他瘿蜂感染的Wolbachia均属于A群。此外,本文采集的栎结瘤瘿蜂和摇鼓栎瘿蜂营有性生殖,说明Wolbachia的共生并不诱导其营产雌孤雌生殖。
Wolbachia is a cytoplasmically inherited bacterium which occurs widely in the reproductive tissues of arthropods. It causes a wide range of alterations to host reproduction, including induction of cytoplasmic incompatibility (CI), parthenogenesis induction (PI), genetic male feminization and male mortality. We examined the presence of Wolbachia in four American gall wasps, Callirhytis punctate Bassett, Dryocosmus palustris Osten Sacken, Antistrophus silphii Gillette and Antistrophus sp. , using polymerase chain reaction and sequence determination of the Wolbachia wsp gene. Wolbachia infection rates were found to be 60% and 36% , in C. punctate and D. palustris, respectively, but no infection was detected in the two Antistrophus species. The two wsp sequences of C. punctata and D. palustris have lengths of 564 bp and 561 bp, respectively, and were 94% similar. Further comparison with known wsp gene sequences in other cynipid wasps revealed a 100% similarity with those in C. punctata and Andricus solitarius ( strain 1 ), Neuroterus macropterus and Synergus crassicornis and a similarity ranging between 79% - 99% in the remaining species. Phylogenic reconstruction of the relationships of Wolbachia strains in Cynipidae with known wsp sequences indicated that the Wolbachia strain of Callirhytis punctata is closely related to that of A. solitaritts ( strain 1 ), N. macropterus, Biorhiza pallida, and S. crassicornis, whereas the Wolbachia strain of D. palustris is closely related to that of A. mairei. Addition of the new wsp sequences did not change Wolbachia' s established pattern of association in cynipid wasps, i. e. , the Wolbachia strain of Ceroptres cerri belongs to the B group whereas that of all other species belong to the A group. Additionally, we used the sexually reproductive generation to examine the presence of Wolbachia both in C. punctate and D. palustris. The results indicate that Wolbachia does not induce parthenogenesis in these species.