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Simple Summary: In this study, the effect of the targeted silencing of OnGCY on the reproduction of the pirate bug Orius nagaii was evaluated. OnGCY silencing significantly inhibited ovarian development and egg production and significantly reduced the expression of the gene encoding the vitellogenin (Vg) gene. These data provide insights into the function of OnGCY in insect reproduction, which could guide research for the mass rearing of natural enemies for the biological control of insect pests. This study identified and characterized the gene encoding recep tor-type guanylate cyclase-22-like (GCY-22; OnGCY) from the pirate bug Orius nagaii, an important biological control agent. The full-length cDNA of the GCY of O. nagaii was obtained by rapid amplification of cDNA ends (RACE); it had a total length of 4888 base pairs (bp), of which the open reading frame (ORF) was 3750 bp, encoding a polypeptide of 1249 amino acid residues. The physicochemical properties of OnGCY were predicted and analyzed by using relevant ExPASy software, revealing a molecular formula of C6502H10122N1698O1869S57, molecular weight of ~143,811.57 kDa, isoelectric point of 6.55, and fat index of 90.04. The resulting protein was also shown to have a signal peptide, two transmembrane regions, and a conserved tyrosine kinase (tyrkc). Silencing OnGCY by RNA interference significantly inhibited ovarian development and decreased fertility in female O. nagaii in the treated versus the control group. Additionally, OnGCY silencing significantly decreased the expression levels of other GCY and Vg genes. Thus, these results clarify the structure and biological function of OnGCY, which has an important role in insect fecundity. The results also provide a reference for agricultural pest control and future large-scale breeding of biological control agents. [ABSTRACT FROM AUTHOR]

This study identified and characterized the gene encoding recep tor-type guanylate cyclase-22-like (GCY-22; OnGCY) from the pirate bug Orius nagaii, an important biological control agent. The full-length cDNA of the GCY of O. nagaii was obtained by rapid amplification of cDNA ends (RACE); it had a total length of 4888 base pairs (bp), of which the open reading frame (ORF) was 3750 bp, encoding a polypeptide of 1249 amino acid residues. The physicochemical properties of OnGCY were predicted and analyzed by using relevant ExPASy software, revealing a molecular formula of C6502H10122N1698O1869S57, molecular weight of ~143,811.57 kDa, isoelectric point of 6.55, and fat index of 90.04. The resulting protein was also shown to have a signal peptide, two transmembrane regions, and a conserved tyrosine kinase (tyrkc). Silencing OnGCY by RNA interference significantly inhibited ovarian development and decreased fertility in female O. nagaii in the treated versus the control group. Additionally, OnGCY silencing significantly decreased the expression levels of other GCY and Vg genes. Thus, these results clarify the structure and biological function of OnGCY, which has an important role in insect fecundity. The results also provide a reference for agricultural pest control and future large-scale breeding of biological control agents.

The mirid bug Cyrtorhinus lividipennis (Reuter) is an important predator that consumes eggs and young nymphs of the brown planthopper Nilaparvata lugens as a primary food source and thus becomes an important member of the rice ecosystem. We identified and characterized the ClPSP gene in C. lividipennis encoding the phosphoserine phosphatase enzyme. The ClPSP has an open reading frame (ORF) of 957 bp encoding a protein with a length of 294bp and it possesses a haloacid dehalogenase-like (HAD) hydrolase, phosphoserine phosphatase, eukaryotic-like (HAD_PSP_eu) conserved domain. Furthermore, the in silico analysis of the ClPSP gene unveiled its distinct characteristics and it serves as a key player in the modulation of amino acids. The ClPSP showed expression in all developmental stages, with higher expression observed in the ovary and fat body. Silencing the ClPSP by RNA interference (RNAi) significantly decreased PSP enzyme activity and expression compared to dsGFP at two days after emergence (2DAE). The dsPSP treatment altered free hemolymph amino acid compositions, resulting in a significant reduction of serine (Ser) and Arginine (Arg) proportions and a significant increase of Threonine (Thr), Cystine (Cys), and Tyrosine (Tyr) in the C. lividipennis female at 2 DAE. Additionally, a hindered total protein concentration in the ovary and fat body, and reduced vitellogenin (Vg) expression, body weight, and number of laid eggs, were also observed. The same treatment also prolonged the preoviposition period and hindered ovarian development. Our data, for the first time, demonstrated the influential role of the PSP gene in modulating the fecundity of C. lividipennis and provide a platform for future insect pest control programs using the PSP gene in modulating fecundity. [ABSTRACT FROM AUTHOR]

Bactrocera tau (Walker) is a fly pest species mainly distributed in Southeast Asia and the South Pacific; it causes substantial ecological and economic issues because of its destructiveness and rapid reproduction. Chemical sterilization technology can reduce the use of insecticides and is widely applied for insect pest control. In this study, the sterilization efficacy of varying concentrations of four chemosterilants, namely, hexamethylphosphoramide (HMPA), CSII Aqua, 5-fluorouracil (5-FU), and colchicine, on adult pumpkin flies was investigated. The results indicated that a solution of 0.03% HMPA had the highest sterilization efficacy. When the number of sterile males was equal to or exceeded 20 times that of untreated males, the hatching rate of offspring eggs was less than 10%. Chemosterilant treatment significantly altered the levels of acid phosphatase (ACP), alkaline phosphatase (AKP), and B. tau vitellogenin (BtVg); these substances have an important impact on reproductive development. The treatment also decreased the size of the reproductive organs (i.e., testes and ovaries). Our results suggest that 0.03% HMPA has unique sterilization properties and may represent a new chemical agent for the control of B. tau populations in agricultural settings.

The mirid bug Cyrtorhinus lividipennis (Reuter) is an important predator that consumes eggs and young nymphs of the brown planthopper Nilaparvata lugens as a primary food source and thus becomes an important member of the rice ecosystem. We identified and characterized the ClPSP gene in C. lividipennis encoding the phosphoserine phosphatase enzyme. The ClPSP has an open reading frame (ORF) of 957 bp encoding a protein with a length of 294bp and it possesses a haloacid dehalogenase-like (HAD) hydrolase, phosphoserine phosphatase, eukaryotic-like (HAD_PSP_eu) conserved domain. Furthermore, the in silico analysis of the ClPSP gene unveiled its distinct characteristics and it serves as a key player in the modulation of amino acids. The ClPSP showed expression in all developmental stages, with higher expression observed in the ovary and fat body. Silencing the ClPSP by RNA interference (RNAi) significantly decreased PSP enzyme activity and expression compared to dsGFP at two days after emergence (2DAE). The dsPSP treatment altered free hemolymph amino acid compositions, resulting in a significant reduction of serine (Ser) and Arginine (Arg) proportions and a significant increase of Threonine (Thr), Cystine (Cys), and Tyrosine (Tyr) in the C. lividipennis female at 2 DAE. Additionally, a hindered total protein concentration in the ovary and fat body, and reduced vitellogenin (Vg) expression, body weight, and number of laid eggs, were also observed. The same treatment also prolonged the preoviposition period and hindered ovarian development. Our data, for the first time, demonstrated the influential role of the PSP gene in modulating the fecundity of C. lividipennis and provide a platform for future insect pest control programs using the PSP gene in modulating fecundity.

As a conserved transcription factor, FoxO plays a crucial role in multiple physiological processes in vivo, including stress resistance, longevity, growth and reproduction. Previous studies on FoxO have focused on human, mouse, Drosophila melanogaster and Caenorhabditis elegans, while there are few reports on agricultural pests and little is known about how FoxO modulates insect fecundity. In Asia, the brown planthopper (BPH) Nilaparvata lugens (Stål) is one of the most serious pests in rice production and high fecundity is the basis of the outbreak of BPH. Here, using the genome-wide ChIP-seq of NlFoxO in BPH, we found that NlFoxO binds to the promoters of ribosomal proteinS6 kinase (NlS6K) and serine/threonine-protein kinase mTOR (NlTOR) and increases their expression levels. We also found that NlFoxO directly binds to the exon of vitellogenin (NlVg) and has a specific inhibitory effect on its expression. In addition, the number of eggs laid and their hatching rate decreased significantly after injection of NlFoxO double-stranded RNA into BPH adults. Our findings provide direct evidence that FoxO modulates insect fecundity through binding to the promoters of NlS6K, NlTOR and the exon of NlVg and affecting their gene expression in the Vg network. [ABSTRACT FROM AUTHOR]

BACKGROUND The miridbug, Cyrtorhinus lividipennis, is a significant predacious enemy of rice planthoppers. The effects of sub-lethal concentrations of triazophos, deltamethrin and imidacloprid on fecundity, egg hatchability, expression levels of genes associated with reproduction, and population growth in C. lividipennis were investigated. RESULTS The fecundities for three pair combinations (♀c × ♂t, ♀t × ♂c and ♀t × ♂t) treated with sub-lethal concentrations of the insecticides triazophos, deltamethrin and imidacloprid (LC10 and LC20) showed a significant increase compared to the untreated pairs (♀c × ♂c). However, sub-lethal concentration treatments did not affect the egg hatchability. The ClVg expression levels of female adults exposed to triazophos, deltamethrin and imidacloprid (LC20) increased by 52.6, 48.9 and 91.2%, respectively. The ClSPATA13 expression level of adult males exposed to triazophos, deltamethrim and imidacloprid (LC20) increased by 80.7, 41.3 and 48.3%, respectively. Furthermore, sub-lethal concentrations of insecticides (LC20) caused increased population numbers in C. lividipennis. CONCLUSION Sub-lethal concentrations of triazophos, deltamethrin and imidacloprid stimulated reproduction and enhanced population growth of C. lividipennis. The reproductive stimulation might result from the up-regulation of ClVg or ClSPATA13. These findings may be useful in mediating populations of planthoppers. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Bactrocera tau (Walker) is a fly pest species mainly distributed in Southeast Asia and the South Pacific; it causes substantial ecological and economic issues because of its destructiveness and rapid reproduction. Chemical sterilization technology can reduce the use of insecticides and is widely applied for insect pest control. In this study, the sterilization efficacy of varying concentrations of four chemosterilants, namely, hexamethylphosphoramide (HMPA), CSII Aqua, 5-fluorouracil (5-FU), and colchicine, on adult pumpkin flies was investigated. The results indicated that a solution of 0.03% HMPA had the highest sterilization efficacy. When the number of sterile males was equal to or exceeded 20 times that of untreated males, the hatching rate of offspring eggs was less than 10%. Chemosterilant treatment significantly altered the levels of acid phosphatase (ACP), alkaline phosphatase (AKP), and B. tau vitellogenin (BtVg); these substances have an important impact on reproductive development. The treatment also decreased the size of the reproductive organs (i.e., testes and ovaries). Our results suggest that 0.03% HMPA has unique sterilization properties and may represent a new chemical agent for the control of B. tau populations in agricultural settings. • 0.03% HMPA has the best sterility effect on B. tau. • HMPA affects the development of B. tau reproductive system via several mechanisms. • HMPA is a potential candidate for controlling crop-damaging B. tau populations. [ABSTRACT FROM AUTHOR]

Highlights: [•] Chemiluminescence (CL) detection with magnetic microparticles and nanoparticles. [•] Principles of CL detection assisted by magnetic microparticles and nanoparticles. [•] Improved features of CL detection with magnetic microparticles and nanoparticles. [•] Improved selectivity of CL detection with magnetic microparticles and nanoparticles. [ABSTRACT FROM AUTHOR]

Highlights: [•] We use silkworm to evaluate the reproductive toxicity of 4-nonylphenol. [•] We detect the effect of 4-nonylphenol on reproductive development of silkworm. [•] 4-Nonylphenol exposure cause impaired reproduction in silkworm. [•] Vitellogenin gene expression can monitor reproductive toxicity in silkworm. [Copyright &y& Elsevier]

The classical role of Vitellogenin (Vg) is providing energy reserves for developing embryos, but its roles appear to extend beyond this nutritional function, and its importance in host immune defense is garnering increasing research attention. However, Vg-regulated immunological functions are dependent on three different domains within different species and remain poorly understood. In the present study, we confirmed three conserved VG domains-LPD_N, DUF1943, and VWD-in the Chinese mitten crab (Eriocheir sinensis), highlighting functional similarities of Vg in vertebrates and invertebrates. Of these three domains, DUF1943 and VWD showed definitive bacterial binding activity via interaction with the signature components on microbial surfaces, but this activity was not exhibited by the LPD_N domain. Antibacterial assays indicated that only the VWD domain inhibits bacterial proliferation, and this function may be conserved between different species due to the conserved amino acid residues. To further explore the relationship between Vg and polymeric immunoglobulin receptor (pIgR), we expressed EspIgR and the three E. sinensis Vg (EsVg) domains in HEK293T cells, and coimmunoprecipitation assay demonstrated that only the DUF1943 domain interacts with EspIgR. Subsequent experiments demonstrated that EsVg regulates hemocyte phagocytosis by binding with EspIgR through the DUF1943 domain, thus promoting bacterial clearance and protecting the host from bacterial infection. To the best of our knowledge, our work is the first to report distinct domains in Vg inducing different immunological outcomes in invertebrates, providing new evidence that pIgR acts as a phagocytic receptor for Vg., Competing Interests: Conflict of interest The authors declare that they have no conflicts of interest with the contents of this article., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)