Isolation and characterization of bacteria associated with silkworm gut under antibiotic-treated larval feeding / Isolamento e caracterização de bactérias associadas ao trato intestinal do bicho-da-seda sob alimentação larval tratada com antibióticos

Abstract The impact of antibiotics on growth, cocoon production was assessed in addition to isolation and characterization of bacteria associated with silkworm gut of infected larvae. Larval rearing was maintained at recommended conditions of temperature and humidity. Silkworm larvae showing abnormal symptoms were collected from the control group and dissected for gut collection. Bacteria were isolated from the gut content by spreading on agar plates and incubated at 37 °C for 48 hrs. Bacterial identification and phylogenetic analysis were carried out by 16S rRNA gene sequencing. The isolated bacteria were subjected to antimicrobial susceptibility test (disc diffusion methods) by using Penicillin (10 µg/mL), Tetracycline (30 µg/mL), Amoxicillin (25 µg/mL), Ampicillin (10 µg/mL), and Erythromycin (15 µg/mL). All isolated strains showed positive results for the catalase test. We isolated and identified bacterial strains (n = 06) from the gut of healthy and diseased silkworm larvae. Based on the 16S rRNA gene sequence, isolated bacteria showed close relation with Serratia, Bacillus, and Pseudomonas spp. Notably, 83.3% of strains were resistant to Penicillin, Tetracycline, Amoxicillin, Ampicillin, and Erythromycin but 16.6% showed antibiotic susceptibility to the above-mentioned commonly used antibiotics. Silkworm larvae fed on penicillin-treated leaves showed significant improvement in larval weight, larval length, and cocoon production. Significantly higher larval weight (6.88g), larval length (5.84cm), and cocoon weight (1.33g) were recorded for larvae fed on leaves treated with penicillin as compared to other antibiotics. Isolated bacterial strains showed close relation with Serratia spp., Bacillus spp. and Pseudomonas spp.

Resumo O impacto dos antibióticos no crescimento e na produção do casulo foi avaliado, além do isolamento e caracterização das bactérias associadas ao intestino de larvas infectadas do bicho-da-seda. A criação das larvas foi mantida nas condições recomendadas de temperatura e umidade. As larvas do bicho-da-seda com sintomas anormais foram coletadas do grupo controle e dissecadas para coleta do intestino. As bactérias foram isoladas do conteúdo intestinal por espalhamento em placas de ágar e incubadas a 37° C durante 48 horas. A identificação bacteriana e a análise filogenética foram realizadas pelo sequenciamento do gene 16S rRNA. As bactérias isoladas foram submetidas a teste de sensibilidade antimicrobiana (métodos de difusão em disco) com penicilina (10 µg / mL), tetraciclina (30 µg / mL), amoxicilina (25 µg / mL), ampicilina (10 µg / mL) e eritromicina (15 µg / mL). Todas as cepas isoladas apresentaram resultados positivos para o teste da catalase. Isolamos e identificamos cepas bacterianas (n = 06) do intestino de larvas de bicho-da-seda saudáveis e doentes. Com base na sequência do gene 16S rRNA, as bactérias isoladas mostraram estreita relação com Serratia, Bacillus e Pseudomonas spp. Notavelmente, 83,3% das cepas eram resistentes a penicilina, tetraciclina, amoxicilina, ampicilina e eritromicina, mas 16,6% mostraram suscetibilidade aos antibióticos comumente usados mencionados acima. As larvas do bicho-da-seda alimentadas com folhas tratadas com penicilina apresentaram melhora significativa no peso larval, comprimento larval e produção de casulo. Peso larval significativamente maior (6,88g), comprimento larval (5,84cm) e peso do casulo (1,33g) foram registrados para larvas alimentadas com folhas tratadas com penicilina, em comparação com outros antibióticos. Cepas bacterianas isoladas mostraram estreita relação com Serratia spp., Bacillus spp. e Pseudomonas spp.

Resistance of bmr energy sorghum hybrids to sugarcane borer and fall armyworm / Resistência de híbridos de sorgo energia bmr à broca-da-cana-de-açúcar e lagarta-do-cartucho

Abstract The lower lignin content in plants species with energy potential results in easier cellulose breakdown, making glucose available for ethanol generation. However, higher lignin levels can increase resistance to insect attack. The objective of this work was to evaluate the susceptibility of a bmr-6 biomass sorghum (a mutant genotype with a lower concentration of lignin) to important pests of energy sorghum, Diatraea saccharalis and Spodoptera frugiperda. Experiments were performed in the laboratory and greenhouse to evaluate the development of these pests on the biomass sorghum bmr hybrids BR007, BR008, and TX635 and their respective conventional near-isogenic genotypes (without the bmr gene). The lignin content was higher in non-bmr hybrids, but the evaluated insect variables varied between treatments, not being consistent in just one hybrid or because it is bmr or not. The lowest survival of S. frugiperda was observed in the BR008 hybrid, both bmr and non-bmr. The S. frugiperda injury scores on plants in the greenhouse were high (>7) in all treatments. For D. saccharalis, there was no difference in larval survival in the laboratory, but in the greenhouse, the BR007 hybrid, both bmr and non-bmr, provided greater survival. Due the need to diversify the energy matrix and the fact that greater susceptibility of the bmr hybrids to either pests was not found in this study, these results hold promise for cultivation of these biomass sorghum hybrids for the production of biofuels.

Resumo O menor teor de lignina em espécies de plantas com potencial energético resulta na maior facilidade de quebra da celulose, disponibilizando glicose para geração de etanol. Porém, maiores teores de lignina representa um fator de resistência ao ataque de insetos. O objetivo deste trabalho foi avaliar como importantes pragas do sorgo energia, Diatraea saccharalis e Spodoptera frugiperda, se comportam quanto à alimentação e desempenho em sorgo bmr-6, um genótipo mutante com menor concentração de lignina. Foram realizados experimentos em laboratório e casa de vegetação, avaliando o desenvolvimento destas pragas nos híbridos de sorgo biomassa bmr 007, 008, TX635 e seus respectivos genótipos isogênicos convencionais (sem o gene bmr). O teor de lignina foi maior nos híbridos não bmr, mas nos parâmetros avaliados nos insetos, houve variação entre os tratamentos, não sendo consistente em apenas um híbrido e nem por ser ou não bmr. A menor sobrevivência de S. frugiperda foi verificada no híbrido BR008 tanto bmr quanto não bmr. As notas de injúria por S. frugiperda no sorgo em casa de vegetação foram altas (>7) em todos os tratamentos. Para D. saccharalis, não houve diferença significativa para a sobrevivência larval em laboratório, mas em casa de vegetação o híbrido BR007 tanto bmr quanto não bmr proporcionaram maior sobrevivência. Diante da necessidade de diversificar a matriz energética e o fato de que não foi comprovada neste estudo maior suscetibilidade dos híbridos bmr a ambas as pragas, estes resultados são promissores para o cultivo desses híbridos de sorgo biomassa para produção de biocombustíveis.

Efficacy of Citrullus colocynthis seed extract on Earias vittella, Fabricius, (Lepidoptera: Noctuidae): environment sustainable approach / Eficácia do extrato de semente de Citrullus colocynthis em Earias vittella Fabricius (Lepidoptera: Noctuidae): abordagem ambiental sustentável

Abstract Earias vittellaFabricius, 1794 (Noctuidae: Lepidoptera) is deliberated to be one of the most destructive pests of cotton and okra vegetation in the world including Asia. The pest has established resistance to various synthetic insecticides. The use of bio-pesticide is one of the unconventional approaches to develop a vigorous ecosystem without harming non- target pests and beneficial natural insect fauna. In the present study, the toxicity levels of Citrullus colocynthis seed extract have been evaluated against the populations of E. vittellaunder standardized laboratory conditions. The toxic effects of C. colocynthis on development periods, protein contents and esterase activity of the life stages of E. vittella were also evaluated. The toxicity levels of methanol, ethanol, hexane, water and profenofos were evaluated on the 1st instar larvae of E. vittella. LC30 and LC80 concentrations exhibited the effectiveness of methanol-based C. colocynthis seed extract against 1st instar larvae of E. vitella. The enhanced larval and pupal periods were revealed in treated samples during the comparison with untreated samples. The intrinsic rate of increase, net reproductive rate in the LC30 and LC80 concentrations exposed larvae remained less than the control treatment. Fecundity, the esterase activity and protein contents were declined in LC30 and LC80 treated samples as compared to the control. The present findings suggest that C. colosynthis extracts based botanical insecticides are beneficial, ecosystem sustainable and can be integrated with insect management programs from environment safety perspective.

Resumo Earias vittella Fabricius, 1794 (Noctuidae: Lepidoptera) é considerada uma das pragas mais destrutivas de algodão e quiabo no mundo, incluindo a Ásia. Essa praga estabeleceu resistência a vários inseticidas sintéticos. O uso de biopesticidas é uma das abordagens não convencionais para desenvolver um ecossistema saudável sem prejudicar as pragas não alvo e a fauna natural benéfica de insetos. No presente estudo, os níveis de toxicidade do extrato de semente de Citrullus colocynthis foram avaliados nas populações de E. vittella em condições de laboratório padronizadas. Os efeitos tóxicos de C. colocynthis nos períodos de desenvolvimento, conteúdo de proteína e atividade esterase das fases de vida de E. vittella também foram avaliados. Os níveis de toxicidade de metanol, etanol, hexano, água e profenofós foram avaliados em larvas de 1º instar de E. vittella. As concentrações de LC30 e LC80 apresentaram eficácia do extrato de sementes de C. colocynthis à base de metanol contra larvas de 1º instar de E. vittella. Os períodos larval e pupal aumentados foram revelados nas amostras tratadas durante a comparação com as amostras não tratadas. A taxa intrínseca de aumento e a taxa reprodutiva líquida nas concentrações de larvas expostas LC30 e LC80 permaneceram menores do que o tratamento controle. A fecundidade, a atividade da esterase e o conteúdo de proteína diminuíram nas amostras tratadas com LC30 e LC80 em comparação com o controle. As presentes descobertas sugerem que os extratos de C. colocynthis à base de inseticidas botânicos são benéficos, sustentáveis ​​para o ecossistema e podem ser integrados com programas de manejo de insetos do ponto de vista da segurança ambiental.

Infestation of Portulaca oleracea (Portulacaceae) plants by Neotuerta platensis (Lepidoptera: Noctuidae) larvae in Brazil: evaluations for five consecutive years / Infestação de plantas de Portulaca oleracea (Portulacaceae) por larvas de Neotuerta platensis (Lepidoptera: Noctuidae) no Brasil: avaliações por cinco anos consecutivos

The bioecology and infestation aspects of Neotuerta platensis Berg, 1882 (Lepidoptera: Noctuidae) on plants are poorly known. This insect fed on the leaves of common purslane, Portulaca oleracea L. (Portulacaceae) for two consecutive years, which triggered its study in the following five years in Januária, Minas Gerais State, Brazil. The objective of this work was to study the bioecology and infestation aspects of N. platensis on P. oleracea plants in the field and laboratory. The mean duration (± SD) of the egg, larva and pupa stages was 3.6 ± 0.89, 11.5 ± 2.81 and 10.7 ± 1.97 days, respectively. The mean numbers of egg masses and eggs per female (± SD) were 3.8 ± 1.16 and 891.6 ± 116.83, respectively. The percentage of infested plants was 59, 74, 0, 78 and 75% and the mean numbers of larvae per plant (± SD) ranged from 0.7 ± 0.45 to 1.6 ± 0.49 individuals, respectively from 2015 to 2019. Neotuerta platensis larvae infested P. oleracea plants in four out of five years evaluated.

Os aspectos de bioecologia e infestação de Neotuerta platensis Berg, 1882 (Lepidoptera: Noctuidae) em plantas são pouco conhecidos. Esse inseto se alimentou das folhas de beldroega comum, Portulaca oleracea L. (Portulacaceae) por dois anos consecutivos, o que desencadeou seu estudo nos cinco anos seguintes em Januária, Minas Gerais, Brasil. O objetivo deste trabalho foi estudar a bioecologia e os aspectos da infestação de N. platensis em plantas de P. oleracea em campo e laboratório. A duração média (± DP) dos estágios de ovo, larva e pupa foi de 3,6 ± 0,89, 11,5 ± 2,81 e 10,7 ± 1,97 dias, respectivamente. Os números médios de posturas e ovos por fêmea (± DP) foram de 3,8 ± 1,16 e 891,6 ± 116,83, respectivamente. A porcentagem de plantas infestadas foi de 59, 74, 0, 78 e 75% e os números médios de larvas por planta (± DP) variaram de 0,7 ± 0,45 a 1,6 ± 0,49 indivíduos, respectivamente de 2015 a 2019. Larvas de N. platensis infestaram plantas de P. oleracea em quatro dos cinco anos avaliados.

Delivering Traumatic Brain Injury to Larval Zebrafish.

We describe a straightforward, scalable method for administering traumatic brain injury (TBI) to zebrafish larvae. The pathological outcomes appear generalizable for all TBI types, but perhaps most closely model closed-skull, diffuse lesion (blast injury) neurotrauma. The injury is delivered by dropping a weight onto the plunger of a fluid-filled syringe containing zebrafish larvae. This model is easy to implement, cost-effective, and provides a high-throughput system that induces brain injury in many larvae at once. Unique to vertebrate TBI models, this method can be used to deliver TBI without anesthetic or other metabolic agents. The methods simulate the main aspects of traumatic brain injury in humans, providing a preclinical model to study the consequences of this prevalent injury type and a way to explore early interventions that may ameliorate subsequent neurodegeneration. We also describe a convenient method for executing pressure measurements to calibrate and validate this method. When used in concert with the genetic tools readily available in zebrafish, this model of traumatic brain injury offers opportunities to examine many mechanisms and outcomes induced by traumatic brain injury. For example, genetically encoded fluorescent reporters have been implemented with this system to measure protein misfolding and neural activity via optogenetics.

Holographic Optogenetic Activation of Neurons Eliciting Locomotion in Head-Embedded Larval Zebrafish.

Understanding how motor circuits are organized and recruited in order to perform complex behavior is an essential question of neuroscience. Here we present an optogenetic protocol on larval zebrafish that allows spatial selective control of neuronal activity within a genetically defined population. We combine holographic illumination with the use of effective opsin transgenic lines, alongside high-speed behavioral monitoring to dissect the motor circuits of the larval zebrafish.

Simultaneous Behavioral and Neuronal Imaging by Tracking Microscopy.

Tracking microscopy enables whole-brain cellular resolution imaging in freely swimming animals. This technique enables both structural and functional imaging without immobilizing the animal, and greatly expands the range of the behaviors accessible to neuroscientists. We use infrared imaging to track the target animal in a behavioral arena. Based on the predicted trajectory of the brain, we apply optimal control theory to a motorized stage system to cancel brain motion in three dimensions. We have combined this motion cancellation system with Differential Illumination Focal Filtering (DIFF), a form of structured illumination microscopy, which enables us to image the brain of a freely swimming larval zebrafish for over an hour. Here we describe the typical experimental procedure for data acquisition and processing using the tracking microscope.

Methods to Study Liver Disease Using Zebrafish Larvae.

Liver disease affects millions of people worldwide, and the high morbidity and mortality is attributed in part to the paucity of treatment options. In many cases, liver injury self-resolves due to the remarkable regenerative capacity of the liver, but in cases when regeneration cannot compensate for the injury, inflammation and fibrosis occur, creating a setting for the emergence of liver cancer. Whole animal models are crucial for deciphering the basic biological underpinnings of liver biology and pathology and, importantly, for developing and testing new treatments for liver disease before it progresses to a terminal state. The cellular components and functions of the zebrafish liver are highly similar to mammals, and zebrafish develop many diseases that are observed in humans, including toxicant-induced liver injury, fatty liver, fibrosis, and cancer. Therefore, the widespread use of zebrafish larvae for studying the mechanisms of these pathologies and for developing potential treatments necessitates the optimization of experimental approaches to assess liver disease in this model. Here, we describe protocols using staining methods, imaging, and gene expression analysis to assess liver injury, fibrosis, and preneoplastic changes in the liver of larval zebrafish.

Brain Imaging and Registration in Larval Zebrafish.

Registration of larval zebrafish brain scans to a common reference brain enables comparison of transgene and gene expression patterns, neuroanatomy, and morphometry. Here we describe methods for staining and mounting larval zebrafish to facilitate whole-brain fluorescence imaging. Following image acquisition, we provide a template for aligning brain images to a reference atlas using nonlinear registration with the ANTs software package.

Altered Visual Function in Short-Wave-Sensitive 1 (sws1) Gene Knockout Japanese Medaka (Oryzias latipes) Larvae.

Visual perception plays a crucial role in foraging, avoiding predators, mate selection, and communication. The regulation of color vision is largely dependent on opsin, which is the first step in the formation of the visual transduction cascade in photoreceptor cells. Short-wave-sensitive 1 (sws1) is a visual pigment that mediates short-wavelength light transduction in vertebrates. The depletion of sws1 resulted in increased M-opsin in mice. However, there is still no report on the visual function of sws1 in teleost fish. Here, we constructed the sws1 knockout medaka using CRISPR/Cas9 technology. The 6 dph (days post-hatching) medaka sws1-/- larvae exhibited significantly decreased food intake and total length at the first feeding stage, and the mRNA levels of orexigenic genes (npy and agrp) were significantly upregulated after feeding. The swimming speed was significantly reduced during the period of dark-light transition stimulation in the sws1-mutant larvae. Histological analysis showed that the thickness of the lens was reduced, whereas the thickness of the ganglion cell layer (GCL) was significantly increased in sws1-/- medaka larvae. Additionally, the deletion of sws1 decreased the mRNA levels of genes involved in phototransduction (gnb3b, grk7a, grk7b, and pde6c). We also observed increased retinal cell apoptosis and oxidative stress in sws1 knockout medaka larvae. Collectively, these results suggest that sws1 deficiency in medaka larvae may impair visual function and cause retinal cell apoptosis, which is associated with the downregulation of photoconduction expression and oxidative stress.

Natural Coumarin Shows Toxicity to Spodoptera litura by Inhibiting Detoxification Enzymes and Glycometabolism.

Coumarin and its derivatives are plant-derived compounds that exhibit potent insecticidal properties. In this study, we found that natural coumarin significantly inhibited the growth and development of Spodoptera litura larvae through toxicological assay. By transcriptomic sequencing, 80 and 45 differentially expressed genes (DEGs) related to detoxification were identified from 0 to 24 h and 24 to 48 h in S. litura after coumarin treatment, respectively. Enzyme activity analysis showed that CYP450 and acetylcholinesterase (AChE) activities significantly decreased at 48 h after coumarin treatment, while glutathione S-transferases (GST) activity increased at 24 h. Silencing of SlCYP324A16 gene by RNA interference significantly increased S. litura larval mortality and decreased individual weight after treatment with coumarin. Additionally, the expression levels of DEGs involved in glycolysis and tricarboxylic acid (TCA) cycle were inhibited at 24 h after coumarin treatment, while their expression levels were upregulated at 48 h. Furthermore, metabonomics analysis identified 391 differential metabolites involved in purine metabolism, amino acid metabolism, and TCA cycle from 0 to 24 h after treated with coumarin and 352 differential metabolites associated with ATP-binding cassette (ABC) transporters and amino acid metabolism. These results provide an in-depth understanding of the toxicological mechanism of coumarin on S. litura.

Continuous Wet Spinning of Regenerated Silk Fibers from Spinning Dopes Containing 4% Fibroin Protein.

The wet spinning of fibers from regenerated silk fibroin has long been a research goal. Due to the degradation of the molecular structure of the fibroin protein during the preparation of the regenerated silk fibroin solution, fibroin concentrations with at least 10% protein content are required to achieve sufficient viscosity for wet spinning. In this study, a spinning dope formulation of regenerated silk fibroin is presented that shows a rheological behavior similar to that of native silk fibroin isolated from the glands of B. mori silkworm larvae. In addition, we present a wet-spinning process that enables, for the first time, the continuous wet spinning of regenerated silk fibroin with only 4% fibroin protein content into an endless fiber. Furthermore, the tensile strength of these wet-spun regenerated silk fibroin fibers per percentage of fibroin is higher than that of all continuous spinning approaches applied to regenerated and native silk fibroin published so far.

Widespread learned predator recognition to an alien predator across populations in an amphibian species.

Alien predators are a major cause of decline and extinction of species worldwide, since native organisms are rarely equipped with specific antipredatory strategies to cope with them. However, phenotypic plasticity and learned predator recognition may help prey populations to survive novel predators. Here we examine geographical variation in the learning ability of larval spadefoot toads (Pelobates cultripes) to recognize invasive predatory crayfish (Procambarus clarkii). We compare the learning-mediated behavioural responses of tadpoles from six populations across two regions in Spain (central and southern), with different histories of exposure to the presence of the invasive species. Two of the populations showed innate recognition of chemical cues from the invasive crayfish, whereas three of them learned to recognize such cues as a threat after conditioning with conspecific alarm cues. Learning abilities did not differ among southern populations, but they did among central populations. We assessed patterns of genetic variation within and among these two regions through microsatellite markers and found low genetic divergence among the southern populations but greater differentiation among the central ones. We hypothesize that similar responses to the invasive crayfish in southern populations may have arisen from a combination of extended historical exposure to this introduced predator (~ 50 y) and higher levels of gene flow, as they inhabit a highly interconnected pond network. In contrast, populations from central Spain show lower connectivity, have been exposed to the invasive crayfish for a shorter period of time, and are more divergent in their plastic responses.

Nacα protects the larval fat body from cell death by maintaining cellular proteostasis in Drosophila.

Protein homeostasis (proteostasis) is crucial for the maintenance of cellular homeostasis. Impairment of proteostasis activates proteotoxic and unfolded protein response pathways to resolve cellular stress or induce apoptosis in damaged cells. However, the responses of individual tissues to proteotoxic stress and evoking cell death program have not been extensively explored in vivo. Here, we show that a reduction in Nascent polypeptide-associated complex protein alpha subunit (Nacα) specifically and progressively induces cell death in Drosophila fat body cells. Nacα mutants disrupt both ER integrity and the proteasomal degradation system, resulting in caspase activation through JNK and p53. Although forced activation of the JNK and p53 pathways was insufficient to induce cell death in the fat body, the reduction of Nacα sensitized fat body cells to intrinsic and environmental stresses. Reducing overall protein synthesis by mTor inhibition or Minute mutants alleviated the cell death phenotype in Nacα mutant fat body cells. Our work revealed that Nacα is crucial for protecting the fat body from cell death by maintaining cellular proteostasis, thus demonstrating the coexistence of a unique vulnerability and cell death resistance in the fat body.

Sulindac selectively induces autophagic apoptosis of GABAergic neurons and alters motor behaviour in zebrafish.

Nonsteroidal anti-inflammatory drugs compose one of the most widely used classes of medications, but the risks for early development remain controversial, especially in the nervous system. Here, we utilized zebrafish larvae to assess the potentially toxic effects of nonsteroidal anti-inflammatory drugs and found that sulindac can selectively induce apoptosis of GABAergic neurons in the brains of zebrafish larvae brains. Zebrafish larvae exhibit hyperactive behaviour after sulindac exposure. We also found that akt1 is selectively expressed in GABAergic neurons and that SC97 (an Akt1 activator) and exogenous akt1 mRNA can reverse the apoptosis caused by sulindac. Further studies showed that sulindac binds to retinoid X receptor alpha (RXRα) and induces autophagy in GABAergic neurons, leading to activation of the mitochondrial apoptotic pathway. Finally, we verified that sulindac can lead to hyperactivity and selectively induce GABAergic neuron apoptosis in mice. These findings suggest that excessive use of sulindac may lead to early neurodevelopmental toxicity and increase the risk of hyperactivity, which could be associated with damage to GABAergic neurons.

Single-Cell Transcriptomic Analysis Reveals the Molecular Profile of Go-Opsin Photoreceptor Cells in Sea Urchin Larvae.

The ability to perceive and respond to light stimuli is fundamental not only for spatial vision but also to many other light-mediated interactions with the environment. In animals, light perception is performed by specific cells known as photoreceptors and, at molecular level, by a group of GPCRs known as opsins. Sea urchin larvae possess a group of photoreceptor cells (PRCs) deploying a Go-Opsin (Opsin3.2) which have been shown to share transcription factors and morphology with PRCs of the ciliary type, raising new questions related to how this sea urchin larva PRC is specified and whether it shares a common ancestor with ciliary PRCs or it if evolved independently through convergent evolution. To answer these questions, we combined immunohistochemistry and fluorescent in situ hybridization to investigate how the Opsin3.2 PRCs develop in the sea urchin Strongylocentrotus purpuratus larva. Subsequently, we applied single-cell transcriptomics to investigate the molecular signature of the Sp-Opsin3.2-expressing cells and show that they deploy an ancient regulatory program responsible for photoreceptors specification. Finally, we also discuss the possible functions of the Opsin3.2-positive cells based on their molecular fingerprint, and we suggest that they are involved in a variety of signaling pathways, including those entailing the thyrotropin-releasing hormone.

Probiotics mitigate kidney damage after exposure to Sri Lanka's local groundwater from chronic kidney disease with uncertain etiology (CKDu) prevalent area in zebrafish.

Groundwater in Sri Lanka, contaminated with environmental toxins, is suspected to potentially induce chronic kidney disease of uncertain etiology (CKDu) in humans. This study aims to elucidate the potential mitigating effects of probiotics on kidney damage induced by exposure to this local groundwater (LW) in zebrafish. We used zebrafish as a model organism and exposed them to local groundwater to evaluate the risk of CKDu. Probiotics were then added at a concentration of 108 colony-forming units per milliliter (CFU/mL). Our findings revealed that exposure to local groundwater resulted in abnormalities, such as tail deletion and spinal curvature in zebrafish larvae. However, the addition of probiotics mitigated these effects, improving the hatching rate, heart rate, length, weight, deformity rate, survival rate, and abnormal behavior of zebrafish. It also positively influenced the differential expression levels of kidney development and immunity-related genes (dync2h1, foxj1, pkd2, gata3, slc20a1, il1ß, and lyso). Furthermore, exposure to LW decreased both the diversity and abundance of microbiota in zebrafish larvae. However, treatment with probiotics, such as L. plantarum and L. rhamnosus partially restored the disrupted gut microbiota and significantly impacted the cellular process pathways of the microbial community, as determined by KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis. In conclusion, this study highlights the risks associated with Sri Lanka's local groundwater from a CKDu prevalent area and confirms the beneficial effects of different probiotics. These findings may provide new insights into bacterial function in host kidney health.

Maize pollen diet enhances malaria mosquito longevity and infectivity to Plasmodium parasites in Ethiopia.

Although larval diet quality may affect adult mosquito fitness, its impact on parasite development is scarce. Plant pollen from Zea mays, Typha latifolia, and Prosopis juliflora was ultraviolet-sterilized and examined for effects on larval development, pupation rate, adult mosquito longevity, survival and infectivity. The control larvae were fed Tetramin fish food as a comparator food. Four treatment and two control groups were used for each pollen diet, and each experimental tray had 25 larvae. Female An. arabiensis were starved overnight and exposed to infectious blood using a membrane-feeding system. The Kaplan-Meier curves and log-rank test were used for analysis. The Z. mays pollen diet increased malaria mosquito survival and pupation rate (91.3%) and adult emergence (85%). Zea mays and Tetramin fish food had comparable adulthood development times. Adults who emerged from larvae fed Z. mays pollen had the longest average wing length (3.72 mm) and were more permissive to P. vivax (45%) and P. falciparum (27.5%). They also survived longer after feeding on infectious blood and had the highest number of P. vivax oocysts. Zea mays pollen improved larval development, adult mosquito longevity, survival and infectivity to Plasmodium. Our findings suggest that malaria transmission in Z. mays growing villages should be monitored.

Microbial signature profiles of Penaeus vannamei larvae in low-survival hatchery tanks affected by vibriosis.

Vibriosis is caused by some pathogenic Vibrio and produces significant mortality in Pacific white shrimp Penaeus (Litopenaeus) vannamei larvae in commercial hatcheries. Acute hepatopancreatic necrosis disease (AHPND) is an emerging vibriosis affecting shrimp-producing countries worldwide. Zoea 2 syndrome is another type of vibriosis that affects the early stages of P. vannamei larvae. Although the pathogenesis of AHPND and zoea 2 syndrome is well known, there is scarce information about microbial composition and biomarkers of P.vannamei larvae affected by AHPND, and there is no study of the microbiome of larvae affected by zoea 2 syndrome. In this work, we characterized the microbiome of P. vannamei larvae collected from 12 commercial hatchery tanks by high-throughput sequencing. Seven tanks were affected by AHPND, and five tanks were affected by zoea 2 syndrome. Subsequently, all samples were selected for sequencing of the V3-V4 region of the16S rRNA gene. Similarity analysis using the beta diversity index revealed significant differences in the larval bacterial communities between disease conditions, particularly when Vibrio was analyzed. Linear discriminant analysis with effect size determined specific microbial signatures for AHPND and zoea 2 syndrome. Sneathiella, Cyclobacterium, Haliea, Lewinella, among other genera, were abundant in AHPND-affected larvae. Meanwhile, Vibrio, Spongiimonas, Meridianimaribacter, Tenacibaculum, among other genera, were significantly abundant in larvae affected by zoea 2 syndrome. The bacterial network at the phylum level for larvae collected from tanks affected by AHPND showed greater complexity and connectivity than in samples collected from tanks affected by zoea 2 syndrome. The bacterial connections inter Vibrio genera were higher in larvae from tanks affected by zoea 2 syndrome, also presenting other connections between the genera Vibrio and Catenococcus. The identification of specific biomarkers found in this study could be useful for understanding the microbial dynamics during different types of vibriosis.

Medium-Chain Fatty Acids Rescue Motor Function and Neuromuscular Junction Degeneration in a Drosophila Model of Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease characterised by progressive degeneration of the motor neurones. An expanded GGGGCC (G4C2) hexanucleotide repeat in C9orf72 is the most common genetic cause of ALS and frontotemporal dementia (FTD); therefore, the resulting disease is known as C9ALS/FTD. Here, we employ a Drosophila melanogaster model of C9ALS/FTD (C9 model) to investigate a role for specific medium-chain fatty acids (MCFAs) in reversing pathogenic outcomes. Drosophila larvae overexpressing the ALS-associated dipeptide repeats (DPRs) in the nervous system exhibit reduced motor function and neuromuscular junction (NMJ) defects. We show that two MCFAs, nonanoic acid (NA) and 4-methyloctanoic acid (4-MOA), can ameliorate impaired motor function in C9 larvae and improve NMJ degeneration, although their mechanisms of action are not identical. NA modified postsynaptic glutamate receptor density, whereas 4-MOA restored defects in the presynaptic vesicular release. We also demonstrate the effects of NA and 4-MOA on metabolism in C9 larvae and implicate various metabolic pathways as dysregulated in our ALS model. Our findings pave the way to identifying novel therapeutic targets and potential treatments for ALS.