Wolbachia affects reproduction in the spider mite Tetranychus truncatus (Acari: Tetranychidae) by regulating chorion protein S38‐like and Rop

Abstract

Wolbachia‐induced reproductive regulation in hosts has been used to control pest populations, but little is known about the molecular mechanism underlying Wolbachia regulation of host genes. Here, reproductive regulation by Wolbachia in the spider mite Tetranychus truncatus was studied at the molecular level. Infection with Wolbachia resulted in decreasing oviposition and cytoplasmic incompatibility in T. truncatus. Further RNA‐seq revealed genes regulated by Wolbachia in T. truncatus. Real‐time quantitative polymerase chain reaction (qPCR) showed that genes, including chorion protein S38‐like and Rop were down‐regulated by Wolbachia. RNA interference (RNAi) of chorion protein S38‐like and Rop in Wolbachia‐uninfected T. truncatus decreased oviposition, which was consistent with Wolbachia‐induced oviposition decrease. Interestingly, suppressing Rop in Wolbachia‐infected T. truncatus led to increased Wolbachia titres in eggs; however, this did not occur after RNAi of chorion protein S38‐like. This is the first study to show that chorion protein S38‐like and Rop facilitate Wolbachia‐mediated changes in T. truncatus fertility. In addition, RNAi of Rop turned the body colour of Wolbachia‐uninfected T. truncatus black, which indicates that the role of Rop is not limited to the reproductive regulation of T. truncatus.

Wolbachia manipulates reproduction of spider mites by influencing herbivore salivary proteins

“…However, expression of SHOT1 genes was not highly induced in WI females of T. truncatus, in which Wolbachia induced decreased oviposition as well. 41 That may be explained by the variations between Wolbachia strains. As Wolbachia in T. urticae and T. truncatus are two different strains (MLST strain type = 292 and 219, respectively).…”

“…The rps18 (ribosomal protein S18, tetur01g03850) gene was the internal control. 41 The relative gene expression levels were quantified as described previously. 42 The primers were selected using PRIMER-BLAST.…”

“…The dsRNA was synthesized using the T7 high yield RNA transcription Kit (Vazyme Biotech) as described previously. 41 The green fluorescent protein (GFP) gene was used as a control. RNAi treatment was performed by soaking mites with dsRNA solution, which has been previously demonstrated to be effective in spider mites.…”

Environmental RNAi-mediated gene silencing in spider mites and its application to pest control

“…他方，近年の技術革新により，dsRNA の合成コストは約 2 USD/g(10 年前の約 5 万分の 1)にまで低下した． 16) この合成 コスト低下と，国や地域によっては GM 作物の推進が困難な イシ イナ ミ ハ ダ ニ(T. truncatus) 63) お よ び ミカ ン ハ ダ ニ (Panonychus citri) [64][65][66][67][68][69][70] において，eRNAi に関する学術論文 が相次いで発表され，その数は筆者が把握している限りで も 40 報以上である(表 1) ．これは，ハダニ類に対する RNA 農薬の研究開発における国際競争が激化していることを示 す．この中には，薬物代謝酵素やその転写因子を標的とした eRNAi によって，化学合成農薬や植物二次代謝産物の殺虫効 果が増強されるといった報告も複数ある． 37,[40][41][42][43][44][45]49,50,52,54,[56][57][58][59][60]65) つまり，eRNAi は，直接的な防除手法としての活用だけでは なく，化学合成農薬や植物防御とも組み合わせた総合的害虫 管理にも資する可能性がある(図 4) ．他方，筆者らのグルー…”

Endosymbionts manipulation of the reproduction and development of spider mites

“…Two copies of the Type V cif wTtru gene were found. The genome also contained a large number of mobile genetic elements which may contribute to sequence variation in cif wTtru (Xia et al 2021(Xia et al , 2022. Partial cytoplasmic incompatibility was induced by cif wTtru in T. truncatus.…”