Search Results (102)

Extreme weather events such as heavy rainfall significantly reduce surface salinity in coastal waters, presenting considerable challenges to the aquaculture of Japanese scallops (Mizuhopecten yessoensis) in shallow cage systems. This study investigated the effects of chronic low-salinity stress on the growth performance, antioxidant capacity, and gene expression profile of M. yessoensis using a 60-day salinity gradient experiment. S33 represents the control treatment with normal seawater salinity (33‰), while S30, S28, and S26 represent experimental groups with progressively lower salinities of 30‰, 28‰, and 26‰, respectively. A decline in salinity was accompanied by an increase in oxygen consumption. The S26 group exhibited a higher ammonia excretion rate (2.73 μg/g·h) than other groups, indicating intensified nitrogen metabolism. Growth was inhibited under low-salinity conditions. The S33 group exhibited greater weight gain (16.7%) and shell growth (8.4%) compared to the S26 group (11.6% and 6%), which also showed a substantially higher mortality rate (46%) compared to the control (13%). At 28‰, antioxidant enzyme activities (T-AOC, SOD, CAT, POD) were elevated, indicating a moderate level of stress. However, at the lowest salinity (26‰), these indicators decreased, reflecting the exhaustion of the antioxidant systems and indicating that the mollusks’ adaptive capacity had been exceeded, leading to a state of stress fatigue. NAD-MDH activity was elevated in the S26 group, reflecting enhanced aerobic metabolism under stress. Transcriptome analysis revealed 564 differentially expressed genes (DEGs) between the S33 and S26 groups. Functional enrichment analysis indicated that these DEGs were mainly associated with immune and stress response pathways, including NF-κB, TNF, apoptosis, and Toll/Imd signaling. These genes are involved in key metabolic processes, such as alanine, aspartate, and glutamate metabolism. Genes such as GADD45, ATF4, TRAF3, and XBP1 were upregulated, contributing to stress repair and antioxidant responses. Conversely, the expressions of CASP3, IKBKA, BIRC2/3, and LBP were downregulated, potentially mitigating apoptosis and inflammatory responses. These findings suggest that M. yessoensis adapts to chronic low-salinity stress through the activation of antioxidant systems, modulation of immune responses, and suppression of excessive apoptosis. This study provides new insights into the molecular mechanisms underlying salinity adaptation in bivalves and offers valuable references for scallop aquaculture and selective breeding programs. Full article

Melanin is an important component of the body color of honeybees, and its formation changes with the age of a capped brood of bees. However, up to now, the regulatory mechanism of melanin formation in honeybees remains unclear. To analyze the differential expression profile of microRNAs (miRNAs) in worker bees of Apis mellifera and to reveal the regulatory roles of differentially expressed miRNAs (DEmiRNAs) and mRNAs in the formation process of melanin during the capped brood stage, we used sRNA-seq technology and related software to analyze samples from four key developmental stages during the capped brood stage, when body color develops in Apis mellifera, namely, mature larvae (L0), pre-pupae (PP3), early pupae (P6) and mid-pupae (P9). A total of 1291 miRNAs were identified by bioinformatics. Three comparison groups were analyzed: L0 vs. PP3, PP3 vs. P6, and P6 vs. P9. A total of 171, 94, and 19 DEmiRNAs were identified in these groups, respectively, which regulate 1481, 690, and 182 differentially expressed target mRNAs (target DEmRNAs). The functional analysis of target DEmRNAs indicated that DEmiRNAs might regulate the formation of capped brood melanin in honeybees by activating expression changes in key genes in signaling pathways, such as the Wnt signaling pathway, melanogenesis, and the Toll and Imd signaling pathway, through activating miR-315-x, miR-8, ple, yellow family genes, wnt1, etc. Our research provides a theoretical basis for future analysis of the regulatory role of miRNAs in the formation of melanin in honeybees. Full article

Background/Objectives: Inherited metabolic disorders (IMDs) are a group of genetic conditions affecting metabolic pathways. The treatment of some IMDs requires the dietary restriction of specific amino acids. IMDs may also necessitate the supplementation of one or more amino acids due to factors such as reduced dietary intake, impaired synthesis, defective transport or absorption, or increased utilization. This literature review aims to evaluate the most recent evidence regarding amino acid supplementation in IMDs, considering not only the prevention of amino acid deficiency and toxic accumulation but also the competition with other toxic metabolites. Methods: A systematic search strategy was developed and applied to PubMed/Medline and Scopus databases to identify relevant studies. Amino acids were categorized into six groups: branched-chain amino acids, aromatic amino acids, sulfur amino acids, urea cycle amino acids, other essential amino acids, and other non-essential amino acids. Results: A total of 24 rare IMDs were evaluated. A final number of 99 selected articles were assessed based on the Oxford Centre for Evidence-Based Medicine 2011 Levels of Evidence. Although this work represents a preliminary non-systematic review, it highlights the need for further studies and data collection. Conclusions: Future research must establish the plasma amino acid levels that indicate the need for supplementation, specify the appropriate dosages (g/day or mg/kg/day), determine the optimal treatment duration, and, crucially, define the target plasma ranges to be maintained for effective management of IMDs. Full article

This study explores the dual effects of selenium (Se) supplementation on silkworm development by analyzing miRNA expression profiles of fat bodies in silkworms under different Se concentrations (50 µM and 200 µM). Compared to the control, 84 miRNAs displayed different expression levels in the F_50 µM group, with 72 miRNAs up-regulated and 12 down-regulated; 152 miRNAs were differentially expressed in the F_200 µM group, with 124 up-regulated and 28 down-regulated. In the F_50 µM group, the target genes of differentially expressed miRNAs were mainly enriched in Toll and Imd signaling pathways, oxidative phosphorylation, and ribosome biogenesis in eukaryotes; however, mainly oxidative phosphorylation, ribosome biogenesis in eukaryotes, and the spliceosome were enriched in the F_200 µM group. Based on the results of the protein–protein interaction network and miRNA-target network, bmo-miR-2a-1-5p and bmo-miR-317-3p_L-2R+2 were screened as key miRNAs in the F_50 µM group and the F_200 µM group, respectively. The bmo-miR-2a-1-5p mainly targeted 10014128 (DREDD), 100862750 (ATF2), and 101744000 (Tak1) genes, which were enriched in Toll and Imd signaling pathways. The bmo-miR-317-3p_L-2R+2 primarily regulated 101738508 (SF3b) and 101746688 (Prp19) genes, which were in the spliceosome pathway. Thus, our results demonstrated that Se supplementation improved the silkworm development via bmo-miR-2a-1-5p miRNA regulation of the Toll and Imd signaling pathways and inhibited it via bmo-miR-317-3p_L-2R+2 miRNA targeting the spliceosome pathway. Our data revealed that 50 µM Se supplementation could improve silkworm productivity; meanwhile, a 200 µM Se treatment displayed toxic effects, leading to impaired development. Full article

Honeybees are of economic importance not only for honey production, but also for crop pollination, which amounts to USD 20 billion per year in the United States. However, the number of honeybee colonies has declined more than 40% during the last few decades. Although this decline is attributed to a combination of factors (parasites, diseases, pesticides, and nutrition), unlike other factors, the effect of nutrition on honeybee health is not well documented. In this study, we assessed the differential expression of seven genes linked to honeybee health under three different diets. These included immune function genes [Cactus, immune deficiency (IMD), Spaetzle)], genes involved in nutrition, cellular defense, longevity, and behavior (Vitellogenin, Malvolio), a gene involved in energy metabolism (Maltase), and a gene associated with locomotory behavior (Single-minded). The diets included (a) commercial pollen patties and sugar syrup, (b) monofloral (anise hyssop), and (c) polyfloral (marigold, anise hyssop, sweet alyssum, and basil). Over the 2.7-month experimental periods, adult bees in controls fed pollen patties and sugar syrup showed upregulated Cactus (involved in Toll pathway) and IMD (signaling pathway controls antibacterial defense) expression, while their counterparts fed monofloral and polyfloral diets downregulated the expression of these genes. Unlike Cactus and IMD, the gene expression profile of Spaetzle (involved in Toll pathway) did not differ across treatments during the experimental period except that it was significantly downregulated on day 63 and day 84 in bees fed polyfloral diets. The Vitellogenin gene indicated that monofloral and polyfloral diets significantly upregulated this gene and enhanced lifespan, foraging behavior, and immunity in adult bees fed with monofloral diets. The expression of Malvolio (involved in sucrose responsiveness and foraging behavior) was upregulated when food reserves (pollen and nectar) were limited in adult bees fed polyfloral diets. Adult bees fed with monofloral diets significantly upregulated the expression of Maltase (involved in energy metabolisms) compared to their counterparts in control diets to the end of the experimental period. Single-Minded Homolog 2 (involved in locomotory behavior) was also upregulated in adult bees fed pollen patties and sugar syrup compared to their counterparts fed monofloral and polyfloral diets. Thus, the food source significantly affected honeybee health and triggered an up- and downregulation of these genes, which correlated with the health and activities of the honeybee colonies. Overall, we found that the companion crops (monofloral and polyfloral) provided higher nutritional benefits to enhance honeybee health than the pollen patty and sugar syrup used currently by beekeepers. Furthermore, while it has been reported that bees require pollen from diverse sources to maintain a healthy physiology and hive, our data on nuclear colonies indicated that a single-species diet (such as anise hyssop) is nutritionally adequate and better or comparable to polyfloral diets. To the best of our knowledge, this is the first report indicating better nutritional benefits from monofloral diets (anise hyssop) over polyfloral diets for honeybee colonies (nucs) in semi-large-scale experimental runs. Thus, we recommend that the landscape of any apiary include highly nutritious food sources, such as anise hyssop, throughout the season to enhance honeybee health. Full article

Oropouche orthobunyavirus (OROV) is an emerging public health concern due to its expanding geographic range and increasing case numbers. In Brazil, 13,785 cases were confirmed in 2024, with an additional 3680 reported by January 2025, according to the Ministry of Health. Initially restricted to the Amazon region, OROV has recently been detected in new areas, highlighting the need for enhanced surveillance and vector control strategies. While Culicoides paraensis is the primary vector, the potential role of other species in transmitting the currently circulating OROV strain in Brazil remains unclear. Here, we experimentally assessed the infectivity and dissemination of a recently isolated Oropouche orthobunyavirus (OROV) strain in two widespread mosquito species, Aedes aegypti and Culex quinquefasciatus, collected from diverse regions of Brazil. Our results demonstrated that both mosquito species were refractory to oral infection, suggesting that natural transmission through these vectors is unlikely. However, in artificial systemic infection, Ae. aegypti showed viral replication and immune system activation, indicating its potential to support OROV replication under specific conditions. Additionally, to assess the potential impact of coinfection, we investigated whether Chikungunya virus (CHIKV), an arbovirus that naturally infects Ae. aegypti, could facilitate OROV infection dynamics in this mosquito species. Our results suggest that coinfection does not promote OROV oral infection. Furthermore, we examined whether OROV systemic infection induced an immune response in Ae aegypti. We analyzed the major immune response pathways—RNAi, Toll, IMD, and JAK-STAT—and observed that the RNAi pathway was the most strongly activated in response to OROV infection in Ae. aegypti. These findings highlight the importance of ongoing surveillance and further studies on OROV evolution, vector adaptation, and transmission dynamics, particularly in urban settings where vector populations and viral interactions may facilitate new epidemiological scenarios. Full article

Despite its ecological and economic importance, many aspects of Varroa destructor’s biology remain poorly understood, particularly its defense mechanisms against pathogens. The limited knowledge of Varroa’s immunity has hindered the development of RNA interference (RNAi)-based strategies targeting immune-related genes. In this study, we investigated the immune gene repertoire of V. destructor by querying its NCBI nr protein database and comparing it to model species of ticks (Ixodes scapularis) and mites (Galendromus occidentalis and Tetranychus urticae). Transcription of candidate immune genes was confirmed by analyzing a de novo assembled transcriptome of V. destructor. Our findings reveal that V. destructor shares key immunological traits with ticks, including lysozymes, chitinases, and thioester-containing proteins (TEPs), but also shares the absence of transmembrane peptidoglycan recognition proteins (PGRPs), Gram-negative binding proteins, and several lectin families involved in pathogen recognition. Additionally, Varroa mites, like ticks, lack homologs of crucial immune signaling components, such as the unpaired ligand (JAK/STAT), Eiger (JNK), and multiple elements of the IMD pathway. They also do not encode canonical antimicrobial peptides (AMPs) like defensins but possess putative homologs of ctenidins, AMPs previously identified in spiders and ticks, which may be adopted as a novel genetic readout for immune response in mites. Our findings lay the groundwork for future functional studies on mite immunity and open new avenues for RNAi-based biocontrol strategies targeting immune pathways to enhance Varroa management. Full article

Cullin 2 (Cul2), a core component of the Cullin-RING E3 ubiquitin ligase complex, is integral to regulating distinct biological processes. However, its role in innate immune defenses remains poorly understood. In this study, we investigated the functional significance of Cul2 in the immune deficiency (IMD) signaling-mediated antimicrobial immune reactions in Drosophila melanogaster (fruit fly). We demonstrated that loss-of-function of Cul2 led to a marked reduction in antimicrobial peptide induction following bacterial infection, which was associated with increased fly mortality and bacterial load. The proteomic analysis further revealed that loss-of-function of Cul2 reduced the expression of Effete (Eff), a key E2 ubiquitin-conjugating enzyme during IMD signaling. Intriguingly, ectopic expression of eff effectively rescued the immune defects caused by loss of Cul2. Taken together, the results of our study underscore the critical role of Cul2 in ensuring robust IMD signaling activation, highlighting its importance in the innate immune defense against microbial infection in Drosophila. Full article

The changes in frequency and intensity of rainfall, variation in temperature, increasing extreme weather events, and rising greenhouse gas emissions can together have a varying impact on food grain production, which then leads to significant impacts on food security in the future. The purpose of this study is to quantify how maize productivity might be affected due to climate change in Southern India. The present study examines how the projected changes to the northeast monsoon will affect maize yield in Tamil Nadu during the rabi season, which spans from September to December, by using a three-step methodology. Firstly, global climate models that accurately represent the large-scale features of the mean monsoon were chosen. Secondly, baseline and future climate data were extracted from the selected global models and the baseline data were compared with observations. Thirdly, the panel data regression model was fitted with the India Meteorological Department’s (IMD) observed climate data to generate the baseline coefficients and projected the maize production using future climate data generated from the global climate model. The Representative Concentration Pathways (RCPs) of RCP4.5 and RCP8.5 were used from two global climate model outputs, namely GFDL_CM3 and HadGEM2_CC, to predict the climate change variability on maize yields during the middle (2021–2050) and the end (2071–2100) of this century. The maize yield is predicted to increase by 3 to 5.47 per cent during the mid-century period and it varies from 7.25 to 14.53 per cent during the end of the century for the medium- (RCP4.5) and high-emission (RCP8.5) climate change scenarios. The maize grain yield increasing during the future periods indicated that the increase in rainfall and temperature during winter in Southern India reduced the possibility of a negative impact of temperature on the maize yield. Full article

Five major antimicrobial peptides (AMPs) in Drosophila are induced in multiple sex combs (mxc) mutant larvae harboring lymph gland (LG) tumors, and they exhibit anti-tumor effects. The effects of other well-known AMPs, Cecropin A and Drosocin, remain unexplored. We investigated the tumor-elimination mechanism of these AMPs. A half-dose reduction in either the Toll or Imd gene reduced the induction of these AMPs and enhanced tumor growth in mxc^mbn1 mutant larvae, indicating that their anti-tumor effects depend on the innate immune pathway. Overexpression of these AMPs in the fat body suppressed tumor growth without affecting cell proliferation. Apoptosis was promoted in the mutant but not in normal LGs. Conversely, knockdown of them inhibited apoptosis and enhanced tumor growth; therefore, they inhibit LG tumor growth by inducing apoptosis. The AMPs from the fat body were incorporated into the hemocytes of mutant but not normal larvae. Another AMP, Drosomycin, was taken up via phagocytosis factors. Enhanced phosphatidylserine signals were observed on the tumor surface. Inhibition of the signals exposed on the cell surface enhanced tumor growth. AMPs may target phosphatidylserine in tumors to induce apoptosis and execute their tumor-specific effects. AMPs could be beneficial anti-cancer drugs with minimal side effects for clinical development. Full article

Spodoptera frugiperda is a major migratory agricultural pest that poses a significant threat to global crop safety. Metarhizium rileyi has emerged as an effective biocontrol agent against lepidopteran pests. In this study, we examined the immune responses of third-instar S. frugiperda larvae at various stages of an M. rileyi infection. Using RNA-seq and microscopic observation, we identified the immune-related pathways enriched at different infection stages, which were further validated by a qRT-PCR. Our findings revealed the following immune responses during infection: During the stage when M. rileyi penetrated the host cuticle (0–48 h), the genes related to energy metabolism, detoxification, and melanization were upregulated. Meanwhile, the TOLL and IMD signaling pathways were activated to counter the infection. During the stage of M. rileyi’s internal infection (48–96 h), which was the peak expression period of the immune-related genes, cellular immunity predominated. Hemocytes encapsulated and phagocytosed the hyphal bodies. Phagocytosis was enhanced through the upregulation of the genes related to ROS and the melanization-related genes, as well as the genes involved in insect hormone biosynthesis. During the stage when M. rileyi grew from the inside to the outside of the host (96–120 h), immune system paralysis resulted in host mortality. These findings deepen our understanding of the immune interactions between M. rileyi and S. frugiperda, support the potential of M. rileyi as an effective biocontrol agent, and provide a theoretical foundation for the development of targeted biopesticides for pests using biotechnological approaches. Full article

The substitution of fishmeal with high-level soybean meal in the diet of crustaceans usually induces lipid accumulation and oxidative stress in the hepatopancreas. Therefore, it is essential to alleviate these adverse effects. In the present study, SBPs were used to alleviate the negative effects of a fishmeal decrease on the growth performance, lipid metabolism, antioxidant capacity, and gut microbiota of oriental river prawn (Macrobrachium nipponense) in an 8-week feeding trial. Three isonitrogenic and isolipidic diets were prepared as follows: R (reference diet with 32% fishmeal), CT (control diet with 22% fishmeal), and SBP (22% fishmeal with 1.25 g/kg soybean bioactive peptides). The prawns (initial biomass per tank 17 g) were randomly divided into three groups with four replicates. The results showed that the low-fishmeal diet induced the following: (1) the inhibition of growth performance and survival of prawns; (2) an increase in triglyceride content in the hepatopancreas and hemolymph and downregulation of carnitine palmitoyl transferase 1 (cpt1) gene expression; (3) a reduction in antioxidant enzymes’ activities and their genes expression levels and an increase malondialdehyde (MDA) content; and (4) an increase in the abundance of the conditional pathogen Pseudomonas in the gut. SBPs supplementation in the CT diet effectively alleviated most of the above adverse effects. SBPs enhanced inducible nitric oxide synthase (iNOS) activity to synthesize nitric oxide (NO) by activating the imd-relish pathway. Most importantly, SBPs increased the potential probiotic Rikenellaceae_RC9_gut_group abundance and decreased the abundance of the conditional pathogen Pseudomonas in the gut. In conclusion, SBPs supplementation can improve low-fishmeal-diet-induced growth inhibition by regulating the gut microbiota composition to ameliorate lipid deposition and oxidative stress and strengthen immune status in oriental river prawn. Full article

Most cases of invasive meningococcal disease (IMD) in Europe are caused by isolates of the Neisseria meningitidis serogroups B, C, W, and Y. We aimed to explore cases caused by other unusual serogroups. We retrospectively screened IMD cases in the databases of the National Reference Center for Meningococci and Haemophilus influnezae in France between 2014 and 2023. Age, sex, serogroups, and genetic lineage distributions were analyzed. We also measured complement deposition on the bacterial surface and tested coverage by vaccines against serogroup B. Cases due to isolates of serogroups other than B, C, W, and Y represented 1.6% of all 3610 IMD cases during the study period with 59 cases and a median age of 21.5 years of age. The corresponding isolates were non-groupable (26 cases), serogroup X (21 cases), serogroup E (11 cases), and one isolate belonged to serogroup Z. Only a low proportion (7.4%) belonged to the hyperinvasive genetic lineages. Isolates of serogroup E bound a significantly higher amount of complement on their surface and were mainly detected in patients with terminal complement pathway deficiencies. Isolates of these unusual serogroups were shown to be covered by vaccines licensed against meningococci B. Surveillance of these isolates needs to be enhanced. Full article

Background: General control nonderepressible 5 (Gcn5) is a lysine acetyltransferase (KAT) that is evolutionarily conserved across eukaryotes, with two homologs (Kat2a and Kat2b) identified in humans and one (Gcn5) in Drosophila. Gcn5 contains a P300/CBP-associated factor (PCAF) domain, a Gcn5-N-acetyltransferase (GNAT) domain, and a Bromodomain, allowing it to regulate gene expression through the acetylation of both histone and non-histone proteins. In Drosophila, Gcn5 is crucial for embryonic development, with maternal Gcn5 supporting early development. However, the functional mechanisms of Gcn5 after the depletion of maternal deposits remain unclear. Methods: Our study employed the Gal4/UAS-RNAi system to achieve whole-body or heart-specific Gcn5 knockdown in Drosophila and selected 96-hour-old surviving larvae for transcriptomic and metabolomic analyses. Results: Omics results revealed that Gcn5 knockdown significantly impacts various metabolic pathways, as well as lysosomes, non-homologous end-joining, Toll and Imd signaling pathways, and circadian rhythms, among others. Furthermore, defects in chitin synthesis may be associated with impaired pupation. Additionally, heart-specific Gcn5 knockdown affected cardiac physiology but appeared to have a potential protective effect against age-related cardiac decline. Conclusions: These findings deepen our understanding of Gcn5’s roles in Drosophila development and provide valuable insights for developing Gcn5-targeted therapies, particularly considering its involvement in various human diseases. Full article

Safe antibiotic substitutes are needed given the rise in antimicrobial resistance, environmental contamination, and stringent antibiotic regulations. Insect-derived antimicrobial peptides (AMPs) are promising candidates due to their antimicrobial activity, stability, and safety. This study investigates the antimicrobial mechanism of crude AMP extracts and their physicochemical characteristics in black soldier fly larvae (BSFL). The results indicated that BSFL reared on a wheat bran diet exhibited significantly improved growth performance and AMP production when compared to the other three diets. AMP extracts showed enhanced antimicrobial activity and physicochemical stability, including temperatures and metal ions except Cu⁺. Moreover, AMP extracts disrupted the cell membrane and inhibited the cell cycle of Staphylococcus aureus (S. aureus), thus exhibiting antimicrobial activity. Furthermore, transcriptomic and KEGG enrichment analyses identified 509 differentially expressed genes (DEGs) related to the Toll and IMD signaling pathways. STRING and GeneMANIA analyses confirmed the association of these pathways with immune response and AMP secretion. qRT-PCR results showed elevated expression of immune genes (GNBP3, NFKBIA, GADD45, and Spz) in BSFL following S. aureus immunization, consistent with RNA-seq findings. These findings offer a valuable reference for using AMPs as antibiotic substitutes in animal feeds and highlight the need for further research on AMP purification and the synergistic regulation of protein synthesis and AMP production in BSFL. Full article