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PloS One 2024Medaka fish (Oryzias latipes) is a powerful model to study genetics underlying the developmental and functional traits of the vertebrate visual system. We established a...
Medaka fish (Oryzias latipes) is a powerful model to study genetics underlying the developmental and functional traits of the vertebrate visual system. We established a simple and high-throughput optomotor response (OMR) assay utilizing medaka larvae to study visual functions including visual acuity and contrast sensitivity. Our assay presents multiple adjustable stripes in motion to individual fish in a linear arena. For that the OMR assay employs a tablet display and the Fish Stripes software to adjust speed, width, color, and contrast of the stripes. Our results demonstrated that optomotor responses were robustly induced by black and white stripes presented from below in the linear-pool-arena. We detected robust strain specific differences in the OMR when comparing long established medaka inbred strains. We observed an interesting training effect upon the initial exposure of larvae to thick stripes, which allowed them to better respond to narrower stripes. The OMR setup and protocol presented here provide an efficient tool for quantitative phenotype mapping, addressing visual acuity, trainability of cortical neurons, color sensitivity, locomotor response, retinal regeneration and others. Our open-source setup presented here provides a crucial prerequisite for ultimately addressing the genetic basis of those processes.
Topics: Animals; Oryzias; Larva; Visual Acuity; Photic Stimulation; Contrast Sensitivity; Vision, Ocular; High-Throughput Screening Assays
PubMed: 38941325
DOI: 10.1371/journal.pone.0302092 -
Frontiers in Bioscience (Elite Edition) May 2024Fall armyworm () is a highly destructive maize pest that significantly threatens agricultural productivity. Existing control methods, such as chemical insecticides and...
BACKGROUND
Fall armyworm () is a highly destructive maize pest that significantly threatens agricultural productivity. Existing control methods, such as chemical insecticides and entomopathogens, lack effectiveness, necessitating alternative approaches.
METHODS
Gut-associated bacteria were isolated from the gut samples of fall armyworm and screened based on their chitinase and protease-producing ability before characterization through 16S rRNA gene sequence analysis. The efficient chitinase-producing FGE4 and FGE18 were chosen to test the biocontrol efficacy. As their respective cell suspensions and extracted crude chitinase enzyme, these two isolates were applied topically on the larvae, supplemented with their feed, and analyzed for their quantitative food use efficiency and survivability.
RESULTS
Twenty-one high chitinase and protease-producing bacterial isolates were chosen. Five genera were identified by 16S rRNA gene sequencing: , , , , and . In the biocontrol efficacy test, the consumption index and relative growth rate were lowered in larvae treated with FGE18 by topical application and feed supplementation. Similarly, topical treatment of FGE4 to larvae decreased consumption index, relative growth rate, conversion efficiency of ingested food, and digested food values.
CONCLUSION
The presence of gut bacteria with high chitinase activity negatively affects insect health. Utilizing gut-derived bacterial isolates with specific insecticidal traits offers a promising avenue to control fall armyworms. This research suggests a potential strategy for future pest management.
Topics: Animals; Spodoptera; Chitinases; RNA, Ribosomal, 16S; Bacteria; Bacillus licheniformis; Enterobacter cloacae; Larva; Pest Control, Biological; Gastrointestinal Tract
PubMed: 38939914
DOI: 10.31083/j.fbe1602015 -
Frontiers in Cellular and Infection... 2024The Asian citrus psyllid (ACP) Kuwayama is the leading vector of Liberibacter asiaticus (Las), the causative agent of citrus Huanglongbing (HLB) disease. The...
The Asian citrus psyllid (ACP) Kuwayama is the leading vector of Liberibacter asiaticus (Las), the causative agent of citrus Huanglongbing (HLB) disease. The distribution and dynamics of Las within ACP are critical to understanding how the transmission, spread and infection of Las occurs within its host vector in nature. In this study, the distribution and titer changes of Las in various tissues of ACP 5 instar nymphs and adults were examined by (FISH) and real-time quantitative PCR (qPCR) techniques. Results demonstrated that 100% of ACP 5 instar nymphs and adults were infected with Las following feeding on infected plants, and that Las had widespread distribution in most of the tissues of ACP. The titers of Las within the midgut, salivary glands and hemolymph tissues were the highest in both 5 instar nymphs and adults. When compared with adults, the titers of Las in these three tissues of 5 instar nymphs were significantly higher, while in the mycetome, ovary and testes they were significantly lower than those of adults. FISH visualization further confirmed these findings. Dynamic analysis of Las demonstrated that it was present across all the developmental ages of ACP adults. There was a discernible upward trend in the presence of Las with advancing age in most tissues of ACP adults, including the midgut, hemolymph, salivary glands, foot, head, cuticula and muscle. Our findings have significant implications for the comprehensive understanding of the transmission, dissemination and infestation of Las, which is of much importance for developing novel strategies to halt the spread of Las, and therefore contribute to the efficient prevention and control of HLB.
Topics: Animals; Hemiptera; Insect Vectors; Plant Diseases; Nymph; Citrus; In Situ Hybridization, Fluorescence; Rhizobiaceae; Real-Time Polymerase Chain Reaction; Salivary Glands; Hemolymph
PubMed: 38938879
DOI: 10.3389/fcimb.2024.1408362 -
Scientific Reports Jun 2024Marine Heatwaves (MHWs) can directly influence survival of marine fishes, particularly for early life stages, including age-0 juveniles during their residence in coastal...
Marine Heatwaves (MHWs) can directly influence survival of marine fishes, particularly for early life stages, including age-0 juveniles during their residence in coastal nursery habitats. However, the ability of nurseries to support high fish densities, optimize foraging and growth, and protect against predators may be altered during MHWs. Gulf of Alaska Pacific cod (Gadus macrocephalus) larval, juvenile, and adult abundances declined dramatically following MHW events in 2014-2016 and 2019. To evaluate coastal nursery function during MHWs, we compared diet composition, recent growth, size, condition, and abundance of age-0 juveniles throughout their first summer before, during, and between MHWs. Diet shifted to larger prey during MHWs, particularly mysids, but diet did not appear to influence growth. We observed faster growth rates during MHWs, yet even when accounting for growth, we could not explain the higher body sizes observed in August during MHWs. Together with lower abundance and the near absence of small fish in the nursery by August during MHWs, these patterns highlight potential for size-selection and a reduced ability of nursery habitats to buffer against environmental variability during MHWs, with only a small number of large "super survivors" persisting through the summer.
Topics: Animals; Ecosystem; Alaska; Gadiformes; Larva; Seasons; Body Size
PubMed: 38937554
DOI: 10.1038/s41598-024-63897-w -
Viruses Jun 2024Honey bees () play a crucial role in agriculture through their pollination activities. However, they have faced significant health challenges over the past decades that...
Honey bees () play a crucial role in agriculture through their pollination activities. However, they have faced significant health challenges over the past decades that can limit colony performance and even lead to collapse. A primary culprit is the parasitic mite , known for transmitting harmful bee viruses. Among these viruses is deformed wing virus (DWV), which impacts bee pupae during their development, resulting in either pupal demise or in the emergence of crippled adult bees. In this study, we focused on DWV master variant B. DWV-B prevalence has risen sharply in recent decades and appears to be outcompeting variant A of DWV. We generated a molecular clone of a typical DWV-B strain to compare it with our established DWV-A clone, examining RNA replication, protein expression, and virulence. Initially, we analyzed the genome using RACE-PCR and RT-PCR techniques. Subsequently, we conducted full-genome RT-PCR and inserted the complete viral cDNA into a bacterial plasmid backbone. Phylogenetic comparisons with available full-length sequences were performed, followed by functional analyses using a live bee pupae model. Upon the transfection of in vitro-transcribed RNA, bee pupae exhibited symptoms of DWV infection, with detectable viral protein expression and stable RNA replication observed in subsequent virus passages. The DWV-B clone displayed a lower virulence compared to the DWV-A clone after the transfection of synthetic RNA, as evidenced by a reduced pupal mortality rate of only 20% compared to 80% in the case of DWV-A and a lack of malformations in 50% of the emerging bees. Comparable results were observed in experiments with low infection doses of the passaged virus clones. In these tests, 90% of bees infected with DWV-B showed no clinical symptoms, while 100% of pupae infected with DWV-A died. However, at high infection doses, both DWV-A and DWV-B caused mortality rates exceeding 90%. Taken together, we have generated an authentic virus clone of DWV-B and characterized it in animal experiments.
Topics: Animals; Bees; RNA Viruses; Phylogeny; Genome, Viral; Virus Replication; Pupa; Virulence; Varroidae; RNA, Viral
PubMed: 38932270
DOI: 10.3390/v16060980 -
Viruses May 2024In this study, we pioneered an alternative technology for manufacturing subunit influenza hemagglutinin (HA)-based vaccines. This innovative method involves harnessing...
In this study, we pioneered an alternative technology for manufacturing subunit influenza hemagglutinin (HA)-based vaccines. This innovative method involves harnessing the pupae of the Lepidoptera () as natural biofactories in combination with baculovirus vectors (using CrisBio technology). We engineered recombinant baculoviruses encoding two versions of the HA protein (trimeric or monomeric) derived from a pandemic avian H7N1 virus A strain (A/chicken/Italy/5093/99). These were then used to infect pupae, resulting in the production of the desired recombinant antigens. The obtained HA proteins were purified using affinity chromatography, consistently yielding approximately 75 mg/L of insect extract. The vaccine antigen effectively immunized poultry, which were subsequently challenged with a virulent H7N1 avian influenza virus. Following infection, all vaccinated animals survived without displaying any clinical symptoms, while none of the mock-vaccinated control animals survived. The CrisBio-derived antigens induced high titers of HA-specific antibodies in the vaccinated poultry, demonstrating hemagglutination inhibition activity against avian H7N1 and human H7N9 viruses. These results suggest that the CrisBio technology platform has the potential to address major industry challenges associated with producing recombinant influenza subunit vaccines, such as enhancing production yields, scalability, and the speed of development, facilitating the global deployment of highly effective influenza vaccines.
Topics: Animals; Influenza Vaccines; Pupa; Influenza in Birds; Vaccines, Subunit; Hemagglutinin Glycoproteins, Influenza Virus; Antibodies, Viral; Chickens; Influenza A Virus, H7N1 Subtype; Baculoviridae; Influenza A Virus, H7N9 Subtype; Humans; Vaccine Development; Moths; Pandemics
PubMed: 38932122
DOI: 10.3390/v16060829 -
International Journal of Molecular... Jun 2024is an essential species for freshwater economic aquaculture in China, but in the larval process, their salinity requirement is high, which leads to salinity stress in...
is an essential species for freshwater economic aquaculture in China, but in the larval process, their salinity requirement is high, which leads to salinity stress in the water. In order to elucidate the mechanisms regulating the response of to acute low-salinity exposure, we conducted a comprehensive study of the response of exposed to different salinities' (0‱, 6‱, and 12‱) data for 120 h. The activities of catalase, superoxide dismutase, and glutathione peroxidase were found to be significantly inhibited in the hepatopancreas and muscle following low-salinity exposure, resulting in oxidative damage and immune deficits in . Differential gene enrichment in transcriptomics indicated that low-salinity stress induced metabolic differences and immune and inflammatory dysfunction in . The differential expressions of , , and genes indicated the inhibition of growth, development, and molting ability of . At the proteomic level, low salinity induced metabolic differences and affected biological and cellular regulation, as well as the immune response. Tyramine, trans-1,2-Cyclohexanediol, sorbitol, acetylcholine chloride, and chloroquine were screened by metabolomics as differential metabolic markers. In addition, combined multi-omics analysis revealed that metabolite chloroquine was highly correlated with low-salt stress.
Topics: Animals; Palaemonidae; Larva; Salt Stress; Transcriptome; Proteomics; Salinity; Gene Expression Profiling; Metabolomics; Oxidative Stress; Multiomics
PubMed: 38928514
DOI: 10.3390/ijms25126809 -
International Journal of Molecular... Jun 2024Chlorpyrifos (CPF) is a widely used organophosphate insecticide, though its excessive use causes environmental contamination, raising concerns about its adverse effects...
Chlorpyrifos (CPF) is a widely used organophosphate insecticide, though its excessive use causes environmental contamination, raising concerns about its adverse effects on human health. In this regard, stands out as a promising candidate for counteracting chemical 'contaminant' toxicity thanks to its therapeutic properties. Therefore, our study aimed to investigate the potential of an ethanolic extract (UDE) to mitigate chlorpyrifos-induced toxicity. Eight compounds in the ethanolic extract have been identified, most of which present significant potential as antioxidant, anti-inflammatory, and neuroprotective agents. Chlorpyrifos exposure altered hatching rates, increased the incidence of teratogenic effects, and upregulated the expression of brain-derived neurotrophic factor (Bdnf) in zebrafish larvae telencephalon. On the other hand, demonstrated a preventive effect against CPF-induced teratogenicity, which is expressed by a lower morphological deformity rate. Moreover, the UDE showed a rather protective effect, maintaining the physiological condition of the telencephalon. Additionally, CPF altered the locomotor behavior of larvae, which was characterized by irregular swimming and increased activity. This defective behavioral pattern was slightly attenuated by the UDE. Our findings suggest that the UDE possesses significant protective properties against CPF-induced toxicity, probably conferred by its natural antioxidant and anti-inflammatory contents. Still, further research is needed to elucidate the recruited mechanisms and implicated pathways on UDE's protective effects.
Topics: Animals; Zebrafish; Chlorpyrifos; Plant Extracts; Larva; Urtica dioica; Antioxidants; Insecticides; Telencephalon
PubMed: 38928336
DOI: 10.3390/ijms25126631 -
International Journal of Molecular... Jun 2024In nature, plants have developed a series of resistance mechanisms to face various external stresses. As understanding of the molecular mechanisms underlying plant...
In nature, plants have developed a series of resistance mechanisms to face various external stresses. As understanding of the molecular mechanisms underlying plant resistance continues to deepen, exploring endogenous resistance in plants has become a hot topic in this field. Despite the multitude of studies on plant-induced resistance, how plants respond to stress under natural conditions remains relatively unclear. To address this gap, we investigated Chinese pine () using pine caterpillar () under natural conditions. Healthy Chinese pine trees, approximately 10 years old, were selected for studying induced resistance in Huangtuliangzi Forestry, Pingquan City, Chengde City, Hebei Province, China. Pine needles were collected at 2 h and 8 h after feeding stimulation (FS) via 10 pine caterpillars and leaf clipping control (LCC), to simulate mechanical damage caused by insect chewing for the quantification of plant hormones and transcriptome and metabolome assays. The results show that the different modes of treatments significantly influence the contents of JA and SA in time following treatment. Three types of differentially accumulated metabolites (DAMs) were found to be involved in the initial response, namely phenolic acids, lipids, and flavonoids. Weighted gene co-expression network analysis indicated that 722 differentially expressed genes (DEGs) are positively related to feeding stimulation and the specific enriched pathways are plant hormone signal transduction and flavonoid biosynthesis, among others. Two TIFY transcription factors ( and ) and a MYB transcription factor () were found to be involved in the interaction between plant hormones, mainly in the context of JA signal transduction and flavonoid biosynthesis. The results of this study provide an insight into how JA activates, serving as a reference for understanding the molecular mechanisms of resistance formation in conifers responding to mandibulate insects.
Topics: Pinus; Animals; Signal Transduction; Plant Growth Regulators; Flavonoids; Gene Expression Regulation, Plant; Larva; Transcriptome; Moths; Biosynthetic Pathways; Plant Leaves; East Asian People
PubMed: 38928063
DOI: 10.3390/ijms25126354 -
Cancers Jun 2024Therapeutic advances in oncology in the 21st century have contributed to significant declines in cancer mortality. Notably, targeted therapies comprised the largest... (Review)
Review
Therapeutic advances in oncology in the 21st century have contributed to significant declines in cancer mortality. Notably, targeted therapies comprised the largest proportion of oncology drugs approved by the United States (US) Food and Drug Administration (FDA) over the past 25 years and have become the standard of care for the treatment of many cancers. However, despite the metamorphosis of the therapeutic landscape, some aspects of cancer drug development have remained essentially unchanged. In particular, the dose-finding methodology originally developed for cytotoxic chemotherapy drugs continues to be implemented, even though this approach no longer represents the most appropriate strategy for modern cancer therapies. In recognition of the need to reconsider assumptions, adapt the dose selection process for newer drugs, and design alternative strategies, the FDA has undertaken several initiatives in recent years to address these concerns. These actions include the launch of Project Optimus in 2021 and the issuance of draft guidance for industry on dose optimization of oncology drugs in 2023. Amid this evolving regulatory environment, the present manuscript reviews case studies for six different targeted cancer therapies, highlighting how dose-finding challenges have been managed to date by oncologists, sponsors, and regulators.
PubMed: 38927886
DOI: 10.3390/cancers16122180