BACKGROUND: Fatty alcohols are the precursors of sex pheromone components, wax esters and hydrocarbons in insects. Fatty acyl-CoA reductases (FARs) are important enzymes required for the reduction of fatty alcohol and thereby contribute to the production of cuticular hydrocarbon (CHC).RESULTS: Based on bioinformatics analyses we identified 17 FAR genes in the brown planthopper, Nilaparvata lugens. RNA interference against these genes demonstrated that ten NlFAR genes were essential for the survival of N. lugens. For instance, knockdown of NlFAR5, 6, 11 or 15 was lethal and caused a slender body shape, while the old cuticles of the respective animals remained attached to the abdomen or failed to split open from the nota. Knockdown of NlFAR9 resulted in a phenotype, with a smooth body surface and a decrease in CHC amounts. Similarly, CHC deficiency in N. lugens resulted in increased adhesion of water droplets and secreted honeydew to the insect surface and the inability of N. lugens to survive in paddy fields with varying humidity. Knockdown of NlFAR1,4,5,6,8,9,11 and 13 additionally resulted in female adult infertility.CONCLUSION: The present study illustrates the structural and functional differences of FAR family genes and provides potential targets for RNA interference-based rice planthopper management.

Heat shock 70kDa proteins (HSP70s) and their cochaperones DNAJs are ubiquitous molecular chaperones, which function as the “HSP70/DNAJ machinery” in a myriad of biological processes. At present, a number of HSP70s have been classified in many species, but studies on DNAJs, especially in insects, are lacking. Here, we first systematically identified and characterized the HSP70 and DNAJ family members in the brown planthopper (BPH), Nilaparvata lugens, a destructive rice pest in Asia. A total of nine HSP70 and 31 DNAJ genes were identified in the BPH genome. Sequence and phylogenetic analyses revealed the high diversity of the NlDNAJ family. Additionally, spatio-temporal expression analysis showed that most NlHSP70 and NlDNAJ genes were highly expressed in the adult stage and gonads. Furthermore, RNA interference (RNAi) revealed that seven NlHSP70s and 10 NlDNAJs play indispensable roles in the nymphal development, oogenesis, and female fertility of N. lugens under physiological growth conditions; in addition, one HSP70 (NlHSP68) was found to be important in the thermal tolerance of eggs. Together, our results in this study shed more light on the biological roles of HSP70/DNAJ in regulating life cycle, coping with environmental stresses, and mediating the interactions within, or between, the two gene families in insects.

Hsp90 (heat shock protein 90) chaperone machinery is considered to be a key regulator of proteostasis under both physiological and stress growth conditions in eukaryotic cells. The high conservation of both the sequence and function of Hsp90 allows for the utilization of various species to explore new phenotypes and mechanisms. In this study, three Hsp90 homologs were identified in the brown planthopper (BPH), Nilaparvata lugens: cytosolic NlHsp90, endoplasmic reticulum (ER) NlGRP94 and mitochondrial NlTRAP1. Sequence analysis and phylogenetic construction showed that these proteins belonged to distinct classes consistent with the predicted localization and suggested an evolutionary relationship between NlTRAP1 and bacterial HtpG (high-temperature protein G). Temporospatial expression analyses showed that NlHsp90 was inducible under heat stress throughout the developmental stage, while NlGRP94 was only induced at the egg stage. All three genes had a significantly high transcript level in the ovary. The RNA interference-mediated knockdown of NlHsp90 its essential role in nymph development and oogenesis under physiological conditions. NlGRP94 was also required during the early developmental stage and played a crucial role in oogenesis, fecundity and late embryogenesis. Notably, we first found that NlHsp90 and NlGRP94 were likely involved in the cuticle structure of female BPH. Together, our research revealed multifunctional roles of Hsp90s in the BPH.

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Background: Research on the correlation between circulating tumor cells (CTCs) and gastric cancer (GC) has increased rapidly in recent years. However, whether CTCs are associated with GC patient prognosis is highly controversial. Objective: This study aims to evaluate the value of CTCs to predict the prognosis of GC patients. Design: A meta-analysis. Data Sources and Methods: We searched the PubMed, Embase, and Cochrane Library databases for studies that reported the prognostic value of CTCs in GC patients before October 2022. The association between CTCs and overall survival (OS) and disease-free survival (DFS)/recurrence-free survival (RFS) and progression-free survival (PFS) of GC patients was assessed. Subgroup analyses were stratified by sampling times (pre-treatment and post-treatment), detection targets, detection method, treatment method, tumor stage, region, and HR (Hazard Ratio) extraction methods. Sensitivity analysis was performed by removing individual studies to assess the stability of the results. Publication bias was evaluated using funnel plots, Egger’s test, and Begg’s test. Results: We initially screened 2000 studies, of which 28 were available for further analysis, involving 2383 GC patients. The pooled analysis concluded that the detection of CTCs was associated with poor OS (HR = 1.933, 95% CI 1.657–2.256, p < 0.001), DFS/RFS (HR = 3.228, 95% CI 2.475–4.211, p < 0.001), and PFS (HR = 3.272, 95% CI 1.970–5.435, p < 0.001). Furthermore, the subgroup analysis stratified by tumor stage ( p < 0.01), HR extraction methods ( p < 0.001), detection targets ( p < 0.001), detection method ( p < 0.001), sampling times ( p < 0.001), and treatment method ( p < 0.001) all showed that CTC detection was associated with poor OS and DFS/RFS for GC patients. Furthermore, the study showed that CTCs were associated with the poor DFS/RFS of GC when CTCs were detected for patients from Asian or No-Asian regions ( p < 0.05). In addition, higher CTCs predicted poorer OS for GC patients who are from Asian regions ( p < 0.001), but without statistical difference for GC patients from No-Asian regions ( p = 0.490). Conclusion: CTC detection in peripheral blood was associated with poor OS, DFS/RFS, and PFS in patients with GC.