Amelogenin domain‐containing NlChP38 is necessary for normal ovulation in the brown planthopper

Abstract

The brown planthopper (BPH), Nilaparvata lugens, is a major threat to rice production. The eggshell plays an important role in insect reproduction. The constituents and formation process of BPH eggshells remains largely unknown. Here, we report a novel eggshell‐associated protein, NlChP38, containing an amelogenin domain, that is essential for normal ovulation in the BPH. NlChP38 is specifically expressed in the follicular cells from egg chambers at both RNA and protein levels. RNA interference of NlChP38 resulted in oocytes with loose and thin eggshell structure and caused ovulation difficulties. Immunofluorescence localization showed NlChP38 is deposited between follicular cells and oocytes during late choriogenesis. These results indicate that NlChP38 plays an important role in eggshell formation and could be a potential target for RNA interference control of the BPH.

Proteolytic activity of the proteasome is required for female insect reproduction

“…In Hemipteran insects, such as Cixius nervosus (Cixiidae) and Javesella pellucida , Conomelus anceps , N. lugens (Delphacidae), the developing oocytes are surrounded by a single layer of follicular cells. At the start of vitellogenesis, each follicular cell generates two nuclei, with the two nuclei positioned one on top of the other in the long axis of each cell [16,51]. Knockdown of NlRpn s disrupted the arrangement of follicular cells surrounding the oocytes.…”

“…4.9. Functional analysis of NlRpn and NlRac genes during ovulation and egg hatching Ovulation and egg hatching experiments were conducted according to Lou et al [16]. Briefly, newly emerged females were microinjected with each dsNlRpn or dsNlRac and royalsocietypublishing.org/journal/rsob Open Biol.…”

“…The DICER1 gene, which is mostly responsible for microRNA precursor processing, was demonstrated to be important for oocyte maturation in the telotrophic ovary [13], while the female-specific gene for bicaudal-C was essential for oogenesis [14]. The Krüppel homologue 1 and Broad-Complex genes regulate ovarian development and jointly determine the number of ovarioles [15], while the mucin - like gene and eggshell-associated NlChP38 genes are specifically expressed in the follicular cells and are vital for ovulation [16,17]. We previously demonstrated the need for the pancreatic lipase-related protein 2 gene in oocyte maturation and development [18].…”

A genome‐wide identification and analysis of the homeobox genes in the brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae)

“…Recently, the molecular basis underlying BPH reproduction has attracted great interest. Facilitated by the assembled genome of the BPH and RNA interference (RNAi)‐mediated gene function assay (Xu et al, 2013; J. Xue et al, 2014), a battery of genes were identified to be involved in the reproduction through affecting a series of reproduction‐associated events including oogenesis (Lu et al, 2018; N. Xu et al, 2019; Zhang et al, 2018), egg hatchability (Cheng et al, 2020; Shen et al, 2019), ovulation (Wu et al, 2017; Lou, Lu et al, 2019), egg transportation (Lou, Shen et al, 2019; Shen et al, 2021), and ovipositor development (K. L. Li et al, 2018; Mao et al, 2019; Zhang et al, 2018). These findings shed important insights into our understanding of BPH reproduction at the molecular level.…”

NADPH Oxidase 5 Is Essential for Molting and Oviposition in a Rice Planthopper Nilaparvata lugens

“…In N. lugens , some progress has been made in understanding its reproductive regulation mechanisms. A mucin-like gene and an eggshell-associated NlChP38 gene, specifically expressed in the follicular cells, are essential for N. lugens oviposition [ 5 , 6 ]. We speculate that there are functional candidate genes contributing to oviposition success, but which remain unexplored.…”