Diversity Of Wolbachia Symbiotic Bacteria And WO Phage In Papilio

Wolbachia is a class of intracellular symbiotic bacteria inherited by the host cytoplasmic matrix.It is widely distributed in arthropods and nematodes,and it is estimated that more than 65%of insects are infected.Wolbachia can produce individuals that are conducive to Wolbachia transmission by participating in a variety of mechanisms that regulate host reproductive activities.Wolbachia is the most common endosymbiont in butterflies.It mainly regulates host reproduction by inducing cytoplasmic incompatibility,male-killing and feminization.In this study,we analyzed the diversity of Wolbachia and its WO phages in 57 species from five families of Wolbachia and its WO phages in nine cities of three provinces in China by amplification of wsp gene,MLST(Multilocus sequence typing)gene and orf7 gene.The main results are as follows.1.Using specific primers of wsp gene,PCR detection for Wolbachia infection was performed on 156 butterfly samples from five families.20 species were confirmed to be infected with Wolbachia,with a species infection rate of 35.1%.Among them,13 species from four families were found to be infected with Wolbachia for the first time.2.Based on sequence analysis of five housekeeper genes(gatB,coxA,hcpA,ftsZ and fbpA),a phylogenetic tree was constructed based on multilocus sequence types(MLST)analysis of 20 butterfly species infected-with Wolbachia.It was found that two species infected with Wolbachia belonged to supergroup A,but the other 15 species belonged to supergroup B.Although MLST analysis for 13 butterfly species infected with Wolbachia was performed for the first time,only Polygonia c-aureum infected with Wolbachia was a new ST sequence type.3.WO phage infection was detected in 20 butterfly species infected with Wolbachia using specific primers of orf7 gene.The results showed that all Wolbachia of 20 species of butterfly were infected with WO phage.The orf7 gene sequencing and cloning results showed that all the other 18 species were multiple infections,except two species of Wolbachia which were WO phage infected single strains.Phylogenetic analysis showed that the WO phage strains were aggregated into seven large branches,and the same Wolbachia strain could infect different strains of phages.The same WO phage strain can infect different Wolbachia strains of different species,indicating the horizontal transmission of WO phage between different Wolbachia strains and even between different host species.