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International Journal of Molecular... Dec 2022The rigorous balance of endocrine signals that control insect reproductive physiology is crucial for the success of egg production. , a blood-feeding insect and main...
The rigorous balance of endocrine signals that control insect reproductive physiology is crucial for the success of egg production. , a blood-feeding insect and main vector of Chagas disease, has been used over the last century as a model to unravel aspects of insect metabolism and physiology. Our recent work has shown that nutrition, insulin signaling, and two main types of insect lipophilic hormones, juvenile hormone (JH) and ecdysteroids, are essential for successful reproduction in ; however, the interplay behind these endocrine signals has not been established. We used a combination of hormone treatments, gene expression analyses, hormone measurements, and ex vivo experiments using the corpus allatum or the ovary, to investigate how the interaction of these endocrine signals might define the hormone environment for egg production. The results show that after a blood meal, circulating JH levels increase, a process mainly driven through insulin and allatoregulatory neuropeptides. In turn, JH feeds back to provide some control over its own biosynthesis by regulating the expression of critical biosynthetic enzymes in the corpus allatum. Interestingly, insulin also stimulates the synthesis and release of ecdysteroids from the ovary. This study highlights the complex network of endocrine signals that, together, coordinate a successful reproductive cycle.
Topics: Animals; Female; Juvenile Hormones; Ecdysteroids; Rhodnius; Insulin; Insect Hormones; Insulin, Regular, Human
PubMed: 36613451
DOI: 10.3390/ijms24010007 -
PloS One 201420-hydroxyecdysone (20E) and juvenile hormone (JH) signaling pathways interact to regulate insect development. Recently, two proteins, a calponin-like Chd64 and...
20-hydroxyecdysone (20E) and juvenile hormone (JH) signaling pathways interact to regulate insect development. Recently, two proteins, a calponin-like Chd64 and immunophilin FKBP39 have been found to play a pivotal role in the cross-talk between 20E and JH, although the molecular basis of interaction remains unknown. The aim of this work was to identify the structural features that would provide understanding of the role of Chd64 in multiple and dynamic complex that cross-links the signaling pathways. Here, we demonstrate the results of in silico and in vitro analyses of the structural organization of Chd64 from Drosophila melanogaster and its homologue from Tribolium castaneum. Computational analysis predicted the existence of disordered regions on the termini of both proteins, while the central region appeared to be globular, probably corresponding to the calponin homology (CH) domain. In vitro analyses of the hydrodynamic properties of the proteins from analytical size-exclusion chromatography and analytical ultracentrifugation revealed that DmChd64 and TcChd64 had an asymmetrical, elongated shape, which was further confirmed by small angle X-ray scattering (SAXS). The Kratky plot indicated disorderness in both Chd64 proteins, which could possibly be on the protein termini and which would give rise to specific hydrodynamic properties. Disordered tails are often involved in diverse interactions. Therefore, it is highly possible that there are intrinsically disordered regions (IDRs) on both termini of the Chd64 proteins that serve as platforms for multiple interaction with various partners and constitute the foundation for their regulatory function.
Topics: Animals; Calcium-Binding Proteins; Circular Dichroism; DNA-Binding Proteins; Drosophila Proteins; Drosophila melanogaster; Ecdysterone; Juvenile Hormones; Microfilament Proteins; Protein Conformation; Protein Structure, Tertiary; Scattering, Small Angle; Sequence Analysis, Protein; Tribolium; X-Ray Diffraction; Calponins
PubMed: 24805353
DOI: 10.1371/journal.pone.0096809 -
Biomolecules Nov 2023Honey bees are typical model organisms for the study of caste differentiation, and the juvenile hormone (JH) is a crucial link in the regulatory network of caste...
Honey bees are typical model organisms for the study of caste differentiation, and the juvenile hormone (JH) is a crucial link in the regulatory network of caste differentiation in honey bees. To investigate the mechanism of JH-mediated caste differentiation, we analyzed the effect of the JH response gene on this process. We observed that expression levels were significantly higher in queen larvae than in worker larvae at the 48 h, 84 h, and 120 h larval stages, and were regulated by JH. Inhibiting expression in honey bee larvae using RNAi could lead to the development of larvae toward workers. We also analyzed the transcriptome changes in honey bee larvae after RNAi and identified 191 differentially expressed genes (DEGs) and 682 differentially expressed alternative splicing events (DEASEs); of these, many were related to honey bee caste differentiation. Our results indicate that regulates caste differentiation in honey bees by acting as a JH-responsive gene.
Topics: Bees; Animals; Juvenile Hormones; Larva; Transcriptome
PubMed: 38002339
DOI: 10.3390/biom13111657 -
Scientific Reports Aug 2022Juvenile hormone (JH) signalling, via its receptor Methoprene-tolerant (Met), controls metamorphosis and reproduction in insects. Met belongs to a superfamily of...
Juvenile hormone (JH) signalling, via its receptor Methoprene-tolerant (Met), controls metamorphosis and reproduction in insects. Met belongs to a superfamily of transcription factors containing the basic Helix Loop Helix (bHLH) and Per Arnt Sim (PAS) domains. Since its discovery in 1986, Met has been characterized in several insect species. However, in spite of the importance as vectors of Chagas disease, our knowledge on the role of Met in JH signalling in Triatominae is limited. In this study, we cloned and sequenced the Dipetalogaster maxima Met transcript (DmaxMet). Molecular modelling was used to build the structure of Met and identify the JH binding site. To further understand the role of the JH receptor during oogenesis, transcript levels were evaluated in two main target organs of JH, fat body and ovary. Functional studies using Met RNAi revealed significant decreases of transcripts for vitellogenin (Vg) and lipophorin (Lp), as well as their receptors. Lp and Vg protein amounts in fat body, as well as Vg in hemolymph were also decreased, and ovarian development was impaired. Overall, these studies provide additional molecular insights on the roles of JH signalling in oogenesis in Triatominae; and therefore are relevant for the epidemiology of Chagas´ disease.
Topics: Animals; Female; Juvenile Hormones; Methoprene; Oogenesis; Triatominae; Vitellogenins
PubMed: 35988007
DOI: 10.1038/s41598-022-18384-5 -
Brazilian Journal of Medical and... Feb 2000Juvenile hormone (JH) exerts pleiotropic functions during insect life cycles. The regulation of JH biosynthesis by neuropeptides and biogenic amines, as well as the... (Review)
Review
Juvenile hormone (JH) exerts pleiotropic functions during insect life cycles. The regulation of JH biosynthesis by neuropeptides and biogenic amines, as well as the transport of JH by specific binding proteins is now well understood. In contrast, comprehending its mode of action on target organs is still hampered by the difficulties in isolating specific receptors. In concert with ecdysteroids, JH orchestrates molting and metamorphosis, and its modulatory function in molting processes has gained it the attribute "status quo" hormone. Whereas the metamorphic role of JH appears to have been widely conserved, its role in reproduction has been subject to many modifications. In many species, JH stimulates vitellogenin synthesis and uptake. In mosquitoes, however, this function has been transferred to ecdysteroids, and JH primes the ecdysteroid response of developing follicles. As reproduction includes a variety of specific behaviors, including migration and diapause, JH has come to function as a master regulator in insect reproduction. The peak of pleiotropy was definitely reached in insects exhibiting facultative polymorphisms. In wing-dimorphic crickets, differential activation of JH esterase determines wing length. The evolution of sociality in Isoptera and Hymenoptera has also extensively relied on JH. In primitively social wasps and bumble bees, JH integrates dominance position with reproductive status. In highly social insects, such as the honey bee, JH has lost its gonadotropic role and now regulates division of labor in the worker caste. Its metamorphic role has been extensively explored in the morphological differentiation of queens and workers, and in the generation of worker polymorphism, such as observed in ants.
Topics: Animals; Bees; Behavior, Animal; Female; Insecta; Juvenile Hormones; Male; Metamorphosis, Biological; Polymorphism, Genetic; Reproduction; Sex Characteristics
PubMed: 10657056
DOI: 10.1590/s0100-879x2000000200003 -
Ecotoxicology and Environmental Safety Sep 2022Insecticides harm the beneficial organisms, such as predatory spiders, through direct killing or regulation of the development and reproduction. In this study, the...
Insecticides harm the beneficial organisms, such as predatory spiders, through direct killing or regulation of the development and reproduction. In this study, the bioassay showed that the treatment of juvenile hormone (JH) analogue fenoxycarb delayed the moulting of Pardosa pseudoannulata, a dominant predatory spider in paddy fields. In order to figure out the regulatory mechanism of fenoxycarb on the spider development, we systematically analyzed JH biosynthesis in P. pseudoannulata. All genes involved in JH biosynthesis pathway were retrieved from the genome of P. pseudoannulata, except for CYP15A1. The absence of CYP15A1 was in agreement with the identification of methyl farnesoate (MF) rather than JH III in the spider. The delayed moulting and decreased expression of JH biosynthesis-related genes in the MF-applied spiderlings supported that MF was an active JH. Fenoxycarb treatment significantly upregulated the transcriptional level of JH biosynthesis-related genes and consequently delayed the spiderling moulting. In the spider development, ecdysteroid played the opposite role, in contrast to MF, to accelerate the development, as our previous study. Here we found that the treatment of ecdysteroid analogue tebufenozide accelerated P. pseudoannulata spiderling moulting, which resulted from the expressional suppression of ecdysteroid biosynthesis-related genes. In total, the JH and ecdysteroid analogues affected the development of P. pseudoannulata by the expressional regulation of biosynthesis-related genes, which would be helpful for the evaluation of hormone analogue insecticides in environmental safety, and useful for the protection and application of P. pseudoannulate and related spider species.
Topics: Animals; Ecdysteroids; Insecticides; Juvenile Hormones; Predatory Behavior; Spiders
PubMed: 35809399
DOI: 10.1016/j.ecoenv.2022.113847 -
Nature Communications Feb 2022In many species including humans, aging reduces female fertility. Intriguingly, some animals preserve fertility longer under specific environmental conditions. For...
In many species including humans, aging reduces female fertility. Intriguingly, some animals preserve fertility longer under specific environmental conditions. For example, at low temperature and short day-length, Drosophila melanogaster enters a state called adult reproductive diapause. As in other stressful conditions, ovarian development arrests at the yolk uptake checkpoint; however, mechanisms underlying fertility preservation and post-diapause recovery are largely unknown. Here, we report that diapause causes more complete arrest than other stresses yet preserves greater recovery potential. During dormancy, germline stem cells (GSCs) incur DNA damage, activate p53 and Chk2, and divide less. Despite reduced niche signaling, germline precursor cells do not differentiate. GSCs adopt an atypical, suspended state connected to their daughters. Post-diapause recovery of niche signaling and resumption of division contribute to restoring GSCs. Mimicking one feature of quiescence, reduced juvenile hormone production, enhanced GSC longevity in non-diapausing flies. Thus, diapause mechanisms provide approaches to GSC longevity enhancement.
Topics: Animals; Cell Differentiation; Cellular Senescence; Checkpoint Kinase 2; DNA Damage; Diapause, Insect; Drosophila Proteins; Drosophila melanogaster; Embryonic Germ Cells; Female; Fertility; Juvenile Hormones; Ovary; Reactive Oxygen Species; Signal Transduction; Stem Cell Niche; Tumor Suppressor Protein p53
PubMed: 35132083
DOI: 10.1038/s41467-022-28347-z -
Journal of Insect Science (Online) Jul 2021Worker division of labor is a defining trait in social insects. Many species are characterized by having behavioral flexibility where workers perform non-typical tasks...
Worker division of labor is a defining trait in social insects. Many species are characterized by having behavioral flexibility where workers perform non-typical tasks for their age depending on the colony's needs. Worker division of labor and behavioral flexibility were examined in the little fire ant Wasmannia auropunctata (Roger, 1863), for which age-related division of labor has been found. Young workers perform nursing duties which include tending of brood and queens, and colony defense, while older workers forage. When nurses were experimentally removed from the colony, foragers were observed carrying out nursing and colony defense duties, yet when foragers were removed nurses did not forage precociously. We also administered juvenile hormone analog, methoprene, to workers. When methoprene was applied, foragers increased their nursing and defense activities while nurses became mainly idle. The behavioral flexibility of foragers of the little fire ant may be evidence of an expansion of worker's repertoires as they age; older workers can perform tasks they have already done in their life while young individuals are not capable of performing tasks ahead of time. This may be an important adaptation associated with the success of this ant as an invasive species.
Topics: Animals; Ants; Introduced Species; Juvenile Hormones; Methoprene; Social Behavior
PubMed: 34436597
DOI: 10.1093/jisesa/ieab059 -
Aging Cell Dec 2003Mutations of the insulin signal pathway in Drosophila melanogaster produce long-lived adults with many correlated phenotypes. Homozygotes of insulin-like receptor (InR)...
Mutations of the insulin signal pathway in Drosophila melanogaster produce long-lived adults with many correlated phenotypes. Homozygotes of insulin-like receptor (InR) and insulin-like receptor substrate (chico) delay time to eclosion, reduce body size, decrease reproduction and increase life span. Because these mutations are expressed through all life stages it is unclear when insulin signals must be reduced to increase life span. As a first analysis of this problem in D. melanogaster we have manipulated the larval diet to determine if changes in metabolic regulation at this stage are sufficient to slow aging. We controlled the dietary yeast fed to third instar larvae and studied the size, mortality, fecundity and hormones of the resulting adults, which were fed a normal, yeast-replete diet. Adults from yeast-deprived larvae phenocopied many traits of InR and chico mutants: small body size, delayed eclosion, reduced ovariole number and reduced age-specific fecundity. But unlike constitutive mutants of the insulin/IGF system, adults from yeast-deprived larvae had normal patterns of demographic senescence, and this was accompanied by normal insulin-like peptide and juvenile hormone syntheses. Surprisingly, the normal aging in these adults was also associated with greatly reduced fecundity. Although nutritional conditions of the larvae can affect the subsequent body size and fecundity of adults, these are not sufficient to slow aging.
Topics: Animals; Body Constitution; Diet; Drosophila melanogaster; Female; Fertility; Insulin; Juvenile Hormones; Larva; Longevity; Male; Mutation; Reproduction; Signal Transduction; Yeasts
PubMed: 14677635
DOI: 10.1046/j.1474-9728.2003.00064.x -
Drug Metabolism and Disposition: the... May 2015Dr. Bernard Brodie's legacy is built on fundamental discoveries in pharmacology and drug metabolism that were then translated to the clinic to improve patient care.... (Review)
Review
Dr. Bernard Brodie's legacy is built on fundamental discoveries in pharmacology and drug metabolism that were then translated to the clinic to improve patient care. Similarly, the development of a novel class of therapeutics termed the soluble epoxide hydrolase (sEH) inhibitors was originally spurred by fundamental research exploring the biochemistry and physiology of the sEH. Here, we present an overview of the history and current state of research on epoxide hydrolases, specifically focusing on sEHs. In doing so, we start with the translational project studying the metabolism of the insect juvenile hormone mimic R-20458 [(E)-6,7-epoxy-1-(4-ethylphenoxy)-3,7-dimethyl-2-octene], which led to the identification of the mammalian sEH. Further investigation of this enzyme and its substrates, including the epoxyeicosatrienoic acids, led to insight into mechanisms of inflammation, chronic and neuropathic pain, angiogenesis, and other physiologic processes. This basic knowledge in turn led to the development of potent inhibitors of the sEH that are promising therapeutics for pain, hypertension, chronic obstructive pulmonary disorder, arthritis, and other disorders.
Topics: Animals; Awards and Prizes; Chronic Pain; Enzyme Inhibitors; Epoxide Hydrolases; Humans; Inactivation, Metabolic; Inflammation; Insect Hormones; Insecta; Juvenile Hormones; Terpenes
PubMed: 25762541
DOI: 10.1124/dmd.115.063339