Intersex Plays a Role in Microbial Homeostasis in the Brown Planthopper

Abstract

Insects harbor a wide variety of symbiotic microorganisms that are capable of regulating host health and promoting host adaptation to their environment and food sources. However, there is little knowledge concerning the mechanisms that maintain the microbial community homeostasis within insects. In this study, we found that the intersex (ix) gene played an essential role in maintaining microbial homeostasis in the brown planthopper (BPH), Nilaparvata lugens. Injection of the double-strand RNA targeting N. lugens ix (Nlix) into the newly emerged females resulted in abnormal expansion of the copulatory bursa of BPH after mating. Further observation by transmission electron microscopy (TEM) revealed that the abnormally enlarged copulatory bursa resulting from dsNlix treatment was full of microorganisms, while in contrast, the copulatory bursa of dsGFP-treated individuals stored a large number of sperm accompanied by a few bacteria. Moreover, RNA-seq analysis showed that the gene responses to bacteria were remarkably enriched in differentially expressed genes (DEGs). In addition, 16s rRNA sequencing indicated that, compared with control samples, changes in the composition of microbes presented in dsNlix-treated copulatory bursa. Together, our results revealed the immune functions of the Nlix gene in maintaining microbial homeostasis and combating infection in BPH.

Intersex is required for female sexual development in Hermetia illucens

“…In the Coleoptera species Cyclommatus metallifer, the silencing of Cmix in females results in a phenotype similar to silencing of Cmdsx (Gotoh et al, 2016). In the Hemiptera species Nilaparvata lugens, disruption of Nlix causes defects in the external genitalia of both sexes and impedes ovarian development (Zhang et al, 2021a, b); Nlix also participates in embryogenesis (Zhang et al, 2021b) and microbial homeostasis (Zhang et al, 2021a). In the Hemiptera species Bemisia tabaci, reduction in Btix expression did not alter the morphology of external genitalia in females but did reduce the expression of the vitellogenin gene and influence the progeny (Liu et al, 2020).…”

“…In the Hemiptera species Nilaparvata lugens , disruption of Nlix causes defects in the external genitalia of both sexes and impedes ovarian development (Zhang et al. , 2021a, b); Nlix also participates in embryogenesis (Zhang et al. , 2021b) and microbial homeostasis (Zhang et al.…”

“…, 2021b) and microbial homeostasis (Zhang et al. , 2021a). In the Hemiptera species Bemisia tabaci , reduction in Btix expression did not alter the morphology of external genitalia in females but did reduce the expression of the vitellogenin gene and influence the progeny (Liu et al.…”