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Veterinary Parasitology Jun 2024The control of the sheep blowfly relies on the use of insecticides. There have been several reports of in vitro and in vivo resistance to the most widely-used flystrike...
The control of the sheep blowfly relies on the use of insecticides. There have been several reports of in vitro and in vivo resistance to the most widely-used flystrike control chemical, dicyclanil. A recent report also described in vitro resistance to imidacloprid in a strain collected from a single property over three consecutive seasons that also showed resistance to dicyclanil. The present study aimed to use in vitro assays to examine five field-collected blowfly strains to determine if this co-occurrence of resistance to dicyclanil and imidacloprid was present more widely in field strains and to also measure resistance patterns to the other currently-used flystrike control chemicals. Each of the strains showed significant levels of resistance to both dicyclanil and imidacloprid: resistance factors at the IC of 9.1-23.8 for dicyclanil, and 8.7-14.1 for imidacloprid. Resistance factors at the IC ranged from 16.5 to 53.7, and 14.6-24.3 for dicyclanil and imidacloprid, respectively. Resistance factors were up to 8.5 for cyromazine at the IC. Resistance to dicyclanil and imidacloprid was suppressed by co-treatment with the cytochrome P450 inhibitor, aminobenzotriazole, implicating this enzyme system in the observed resistances. We discuss the implications of the co-occurrence of resistance to dicyclanil and imidacloprid on insecticide rotation strategies for blowfly control. We also discuss the roles of insecticide resistance, environmental factors (e.g. rainfall), operational factors (e.g. insecticide application technique) and other animal health issues (e.g. scouring / diarrhoea) that together will impact on the likelihood of flystrike occurring at an earlier time point than expected after insecticide application.
Topics: Animals; Insecticide Resistance; Insecticides; Neonicotinoids; Nitro Compounds; Diptera; Sheep; Sheep Diseases; Juvenile Hormones; Triazines
PubMed: 38569277
DOI: 10.1016/j.vetpar.2024.110178 -
ELife Apr 2024To gain insights into how juvenile hormone (JH) came to regulate insect metamorphosis, we studied its function in the ametabolous firebrat, . Highest levels of JH occur...
To gain insights into how juvenile hormone (JH) came to regulate insect metamorphosis, we studied its function in the ametabolous firebrat, . Highest levels of JH occur during late embryogenesis, with only low levels thereafter. Loss-of-function and gain-of-function experiments show that JH acts on embryonic tissues to suppress morphogenesis and cell determination and to promote their terminal differentiation. Similar embryonic actions of JH on hemimetabolous insects with short germ band embryos indicate that JH's embryonic role preceded its derived function as the postembryonic regulator of metamorphosis. The postembryonic expansion of JH function likely followed the evolution of flight. Archaic flying insects were considered to lack metamorphosis because tiny, movable wings were evident on the thoraces of young juveniles and their positive allometric growth eventually allowed them to support flight in late juveniles. Like in , we assume that these juveniles lacked JH. However, a postembryonic reappearance of JH during wing morphogenesis in the young juvenile likely redirected wing development to make a wing pad rather than a wing. Maintenance of JH then allowed wing pad growth and its disappearance in the mature juvenile then allowed wing differentiation. Subsequent modification of JH action for hemi- and holometabolous lifestyles are discussed.
Topics: Animals; Juvenile Hormones; Metamorphosis, Biological; Insecta; Morphogenesis
PubMed: 38568859
DOI: 10.7554/eLife.92643 -
BMC Genomics Apr 2024Food security is important for the ever-growing global population. Soybean, Glycine max (L.) Merr., is cultivated worldwide providing a key source of food, protein and...
Food security is important for the ever-growing global population. Soybean, Glycine max (L.) Merr., is cultivated worldwide providing a key source of food, protein and oil. Hence, it is imperative to maintain or to increase its yield under different conditions including challenges caused by abiotic and biotic stresses. In recent years, the soybean pod-sucking stinkbug Riptortus pedestris has emerged as an important agricultural insect pest in East, South and Southeast Asia. Here, we present a genomics resource for R. pedestris including its genome assembly, messenger RNA (mRNA) and microRNA (miRNA) transcriptomes at different developmental stages and from different organs. As insect hormone biosynthesis genes (genes involved in metamorphosis) and their regulators such as miRNAs are potential targets for pest control, we analyzed the sesquiterpenoid (juvenile) and ecdysteroid (molting) hormone biosynthesis pathway genes including their miRNAs and relevant neuropeptides. Temporal gene expression changes of these insect hormone biosynthesis pathways were observed at different developmental stages. Similarly, a diet-specific response in gene expression was also observed in both head and salivary glands. Furthermore, we observed that microRNAs (bantam, miR-14, miR-316, and miR-263) of R. pedestris fed with different types of soybeans were differentially expressed in the salivary glands indicating a diet-specific response. Interestingly, the opposite arms of miR-281 (-5p and -3p), a miRNA involved in regulating development, were predicted to target Hmgs genes of R. pedestris and soybean, respectively. These observations among others highlight stinkbug's responses as a function of its interaction with soybean. In brief, the results of this study not only present salient findings that could be of potential use in pest management and mitigation but also provide an invaluable resource for R. pedestris as an insect model to facilitate studies on plant-pest interactions.
Topics: Animals; Glycine max; Heteroptera; Transcriptome; MicroRNAs; Gene Expression Profiling; Insect Hormones
PubMed: 38565997
DOI: 10.1186/s12864-024-10232-2 -
BioRxiv : the Preprint Server For... Mar 2024Juvenile hormone (JH) is one of the most essential hormones controlling insect metamorphosis and physiology. While it is well known that JH affects many tissues...
Juvenile hormone (JH) is one of the most essential hormones controlling insect metamorphosis and physiology. While it is well known that JH affects many tissues throughout the insects life cycle, the difference in JH responsiveness and the repertoire of JH-inducible genes among different tissues has not been fully investigated. In this study, we monitored JH responsiveness using transgenic flies carrying a () construct. Our data highlight the high responsiveness of the epithelial cells within the seminal vesicle, a component of the male reproductive tract, to JH. Specifically, we observe an elevation in the JHRE-GFP signal within the seminal vesicle epithelium upon JH analog administration, while suppression occurs upon knockdown of genes encoding the intracellular JH receptors, and . Starting from published transcriptomic and proteomics datasets, we next identified as a JH-response gene expressed in the seminal vesicle epithelium, suggesting insect seminal vesicles undergo metabolic regulation by JH. Together, this study sheds new light on biology of the insect reproductive regulatory system.
PubMed: 38562788
DOI: 10.1101/2024.03.20.585833 -
Environmental Pollution (Barking, Essex... May 2024Acetamiprid is the only neonicotinoid registered in the European Union because the risks of neonicotinoids to honey bees and other pollinators are strictly regulated....
Acetamiprid is the only neonicotinoid registered in the European Union because the risks of neonicotinoids to honey bees and other pollinators are strictly regulated. Herein, we orally exposed honey bee colonies to sublethal concentrations of acetamiprid (20 μg/L) under isolated conditions. After one month of continuous exposure, the emerging bees and queens were collected and analyzed via high-throughput label-free quantitative proteomics using a data-independent acquisition strategy. Six and 34 significantly differentially expressed proteins (DEPs) were identified in the emerging bees and queens, respectively. Mrjp3 was the only DEP found in both sample types/castes, and its opposite regulation illustrated a differential response. The DEPs in the emerging bees (H/ACA RNP, Rap1GAP, Mrjp3, and JHE) suggested that sublethal exposure to acetamiprid affected cell cycle-related signaling, which may affect the life history of workers in the colony. The DEPs with increased levels in queens, such as Mrjps 1-4 and 6-7, hymenoptaecin, and apidaecin 22, indicated an activated immune response. Additionally, the level of farnesyl pyrophosphate synthase (FPPS), which is essential for the mevalonate pathway and juvenile hormone biosynthesis, was significantly decreased in queens. The impaired utilization of juvenile hormone in queens supported the identification of additional DEPs. Furthermore, the proteome changes suggested the existence of increased neonicotinoid detoxification by UDP-glucuronosyltransferase and increased amino acid metabolism. The results suggest that the continuous exposure of bee colonies to acetamiprid at low doses (nanograms per gram in feed) may pose a threat to the colonies. The different exposure routes and durations for the emerging bees and queens in our experiment must be considered, i.e., the emerging bees were exposed as larvae via feeding royal jelly and beebread provided by workers (nurse bees), whereas the queens were fed royal jelly throughout the experiment. The biological consequences of the proteomic changes resulting from sublethal/chronic exposure require future determination.
Topics: Animals; Bees; Neonicotinoids; Juvenile Hormones; Female; Insecticides; Signal Transduction; Proteomics
PubMed: 38556147
DOI: 10.1016/j.envpol.2024.123901 -
Environmental Toxicology and Chemistry May 2024Current standard toxicity tests on nontarget soil invertebrates mainly focus on the endpoints survival and reproduction. Such results are likely insufficient to predict...
Current standard toxicity tests on nontarget soil invertebrates mainly focus on the endpoints survival and reproduction. Such results are likely insufficient to predict effects at higher organizational levels, for example, the population level. We assessed the effects of exposure to the pesticide teflubenzuron on the collembolan Folsomia candida, by performing a full life-cycle experiment exposing single individuals via contaminated food (uncontaminated control and 0.2, 0.32, 0.48, 0.72, 1.08, and 1.6 mg/kg dry yeast). Several life-history traits were considered by following the growth and development of newly hatched individuals over a period of 65 days. We assessed survival, body length, time to first oviposition, cumulative egg production, and hatchability of eggs. A two-stage model was applied to calculate the population growth rate (λ) combined with elasticity analysis to reveal the relative sensitivity of λ to the effects of teflubenzuron on each life-history parameter. Body length was the least sensitive life-history parameter (median effective concentration = 1.10 mg teflubenzuron/kg dry yeast) followed by time to first oviposition (0.96 mg/kg), survival (median lethal concentration = 0.87 mg/kg), cumulative egg production (0.32 mg/kg), and egg hatchability (0.27 mg/kg). Population growth decreased with increasing concentrations of teflubenzuron (λ = 1.162/day in control to 1.005/day in 0.72 mg/kg dry yeast, with populations going extinct at 1.08 and 1.6 mg/kg dry yeast). Elasticity analysis showed that changes in juvenile survival had a greater impact on the population growth rate compared with the other life-history traits. Our study provides a comprehensive overview of individual-level effects of long-term exposure to teflubenzuron and integrates these effects to assess the potential risk to collembolan populations. Environ Toxicol Chem 2024;43:1173-1183. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
Topics: Animals; Juvenile Hormones; Benzamides; Arthropods; Population Growth; Life Cycle Stages; Phenyl Ethers; Female
PubMed: 38546206
DOI: 10.1002/etc.5850 -
The Journal of International Medical... Mar 2024Androgen insensitivity syndrome (AIS) is a rare disorder with X-linked recessive inheritance in 46 XY patients. The clinical manifestations vary between patients,...
Androgen insensitivity syndrome (AIS) is a rare disorder with X-linked recessive inheritance in 46 XY patients. The clinical manifestations vary between patients, especially regarding external genitalia development. Herein, the case of AIS in a 13-year-old male, who was born with hypospadias and presented to the hospital with gynaecomastia that had developed from 8 years of age, is reported. No micropenis, cryptorchidism or bifid scrotum were found. Testis volume was 12 ml on both sides. His testosterone and luteinizing hormone levels were normal compared with sex- and age-adjusted reference range. His bone age was approximately 13 years according to Greulich-Pyle assessment. Sequence analysis of the androgen receptor () gene revealed a mutation (c.2041A>G) in exon 4, a novel mutation site in the gene. Prediction analysis suggested this to be a disease-causing variant. A milder clinical presentation and normal hormone levels in cases of partial AIS might differ from the usually reported signs and symptoms. A diagnosis of AIS should not be ignored in teenage patients who present with gynaecomastia and hypospadias, but normal hormone levels.
Topics: Male; Adolescent; Humans; Androgen-Insensitivity Syndrome; Gynecomastia; Receptors, Androgen; Hypospadias; Mutation; Testosterone
PubMed: 38530023
DOI: 10.1177/03000605241232520 -
Toxicology May 2024Chlorpyrifos is an organophosphate insecticide used to control pests in crops. Thus, humans are constantly exposed through ingestion of contaminated food or water,...
Chlorpyrifos is an organophosphate insecticide used to control pests in crops. Thus, humans are constantly exposed through ingestion of contaminated food or water, inhalation of contaminated air, and through the skin. The juvenile and peripubertal periods comprise a window of development of the reproductive system, sensitive to toxic agents. Considering the scarcity of data on exposure to the insecticide during these periods, the aim of this study was to evaluate the effects of chlorpyrifos on the testis during the juvenile and peripubertal periods. Thirty Wistar rats with an initial age of 25 days were distributed into 3 groups: control, which received corn oil (vehicle); CPS5, which received 5 mg/Kg b.w. of chlorpyrifos; and CPS15, which received 15 mg/Kg b.w. of chlorpyrifos. The groups were treated via gavage daily for 40 days and on the 41st experimental day, the animals were anesthetized and submitted to euthanasia to collect the organs. Blood was collected to obtain plasma and testosterone measurement. The testicles were removed, weighed and used for sperm count analyses, histopathological and morphometric analyzes and for oxidative stress analyses. Spermatozoa from the vas deferens were collected for analyzes of sperm morphology and acrosome integrity. The results showed that the two concentrations of chlorpyrifos caused a decrease in the number of Leydig and Sertoli cells and germ cells and increased the number of morphologically abnormal sperm and sperm with acrosomal damage. Furthermore, a decrease in lipid peroxidation was observed in the CPS5 and CPS15 groups, and a decrease in glutathione-S-transferase activity in the CPS5 group. We conclude that exposure to chlorpyrifos harms the daily production of sperm, as well as their quality, in addition to causing an imbalance in the oxidoreductive balance of the testicle.
Topics: Animals; Male; Chlorpyrifos; Rats, Wistar; Insecticides; Spermatozoa; Leydig Cells; Sertoli Cells; Rats; Sexual Maturation; Oxidative Stress; Testosterone; Testis; Sperm Count
PubMed: 38522820
DOI: 10.1016/j.tox.2024.153789 -
International Journal of Surgery Case... Apr 2024Although female victims of sexual child abuse present with symptoms such as local pain and vaginal bleeding, however, before any definitive diagnosis a comprehensive...
INTRODUCTION
Although female victims of sexual child abuse present with symptoms such as local pain and vaginal bleeding, however, before any definitive diagnosis a comprehensive physical examination along with a detailed history related to vaginal bleeding should be taken from the patient. Undoubtedly, we must not forget that only one of the causes of vaginal bleeding is rape. Therefore, before making a final diagnosis, other causes of this symptom must be carefully examined.
CASE PRESENTATION
The patient was a 6-years-old female who was hospitalized for notable generalized abdominal distention, acute lower abdomen pain associated with nausea and mild fever lasting 5 days progressively worsening, thelarche and vaginal bleeding. Ultrasound examination showed that multilocular-solid masses located in right side of abdomen which led to surgery and mass excision. Histopathology diagnosis was a juvenile granulosa cell tumor of the ovary.
DISCUSSION
Among the various causes of peripheral premature puberty, granulosa cell tumor (GCT) is rare but very important. Since in the two age groups - prepuberty and menopause - we don't expect to see vaginal bleeding, the occurrence of this disorder especially in association with breast enlargement in prepubertal group, need to appropriate imaging including pelvic ultrasound and bone age determination also laboratory data such as level of sex hormones and tumor markers to avoid misdiagnosis.
CONCLUSION
We report the case of a granulosa cell tumor patient with vaginal bleeding that a complete history and examination provides the right path to a diagnosis.
PubMed: 38513413
DOI: 10.1016/j.ijscr.2024.109546 -
Pediatric Rheumatology Online Journal Mar 2024Systemic juvenile idiopathic arthritis (sJIA) is a severe form of juvenile arthritis that is characterized by chronic joint inflammation and systemic symptoms such as...
BACKGROUND
Systemic juvenile idiopathic arthritis (sJIA) is a severe form of juvenile arthritis that is characterized by chronic joint inflammation and systemic symptoms such as fever, rash, and organ involvement. Anti-IL-6 receptor monoclonal antibody tocilizumab is an effective treatment. However, some patients still experience persisting or recurrent symptoms and the real-world effectiveness of canakinumab in Chinese patients with sJIA has never been reported. Therefore, this study aimed to assess the efficacy and safety of canakinumab in Chinese patients with sJIA using real-world data.
METHODS
We conducted a retrospective study on children with active sJIA. Clinical features, laboratory data, corticosteroid dosage, and adverse events (AEs) were collected at baseline and at 4, 8, 12, and 24 weeks after initiating canakinumab treatment.
RESULTS
Seven female and four male patients were included in the study. All patients had previously been treated with tocilizumab and were administered canakinumab for 12.4 ± 3.4 months. Notably, significant improvements were observed in both clinical signs and symptoms as well as laboratory indicators. Four children under corticosteroid treatment were able to successfully discontinue their corticosteroid therapy: one at week 4, two at week 12, and one at week 24. Notably, there was a significant reduction in the number of tender and swollen joints (P = 0.0059) as well as the systemic juvenile arthritis disease activity score (P < 0.0001). The most common AE was infection, but no patients experienced serious AEs. No cases of macrophage activation syndrome or death were reported during the follow-up period.
CONCLUSIONS
Canakinumab was found to be potentially efficacious and safe in Chinese patients with sJIA. No new AEs were observed with canakinumab treatment.
Topics: Child; Humans; Male; Female; Arthritis, Juvenile; Antibodies, Monoclonal; Retrospective Studies; Adrenal Cortex Hormones; Antibodies, Monoclonal, Humanized
PubMed: 38504360
DOI: 10.1186/s12969-024-00974-4