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Current Opinion in Insect Science Oct 2018The juvenile hormones (JHs) are a family of insect acyclic sesquiterpenoids produced by the corpora allata (CA), a pair of endocrine glands connected to the brain. They... (Review)
Review
The juvenile hormones (JHs) are a family of insect acyclic sesquiterpenoids produced by the corpora allata (CA), a pair of endocrine glands connected to the brain. They are involved in the regulation of development, reproduction, behavior, caste determination, diapause, stress response, and numerous polyphenisms. In the post-genomics era, comprehensive analyses using functional 'omics' technologies such as transcriptomics, proteomics and metabolomics have increased our understanding of the activity of the minute CA. This review attempts to summarize some of the 'omics' studies that have contributed to further understand JH synthesis in insects, with an emphasis on our own research on the mosquito Aedes aegypti.
Topics: Aedes; Animals; Gene Expression Profiling; Insect Proteins; Insecta; Juvenile Hormones; Metabolome; Metabolomics; Proteome; Proteomics; Transcriptome
PubMed: 30551825
DOI: 10.1016/j.cois.2018.05.013 -
General and Comparative Endocrinology Jul 2021The juvenile hormone (JH) plays a crucial role in arthropod physiological processes, e.g., the regulation of metamorphosis, development, and reproduction (the...
The juvenile hormone (JH) plays a crucial role in arthropod physiological processes, e.g., the regulation of metamorphosis, development, and reproduction (the vitellogenesis, the development of gonads, egg production). Still, data about this sesquiterpenoid hormone in spiders (Araneae) are rudimentary and equivocal. The presence of the JH or its precursors (e.g. methyl farnesoate) is not confirmed in spiders. The site of synthesis of its is still undetermined. No receptors of the JH are identified in spiders and thus, the molecular mechanism of action of this group of hormones is still unknown. Here we show by using the phylogenetic analysis and qPCR method the presence of the transcript of the enzyme catalyzing the last phase of the JH biosynthesis pathway (epox CYP15A1), the JH receptor (Met), and a possible candidate to the methyl farnesoate receptor (USP) in the various tissues and stages of ontogenesis in both sexes of spider Parasteatoda tepidariorum. Our results indicate that the juvenile hormone and/or methyl farnesoate presence is possible in the species of spider P. tepidariorum. The presence of the Ptepox CYP15A1 gene suggests that the main site of the juvenile hormone synthesis can be the integument and not the Schneider organ 2. It also seems that the juvenile hormone and/or methyl farnesoate can be hormones with biological activity due to the presence of the transcript of insect and crustacean JH/MG receptor - Met. The Ptepox CYP15A1, PtMet, and Ptusp expression are sex-, tissue-and time-specific. This study is the first report about the presence of the Ptepox CYP15A1 and PtMet transcripts in the Arachnida, which may indicate the presence of the juvenile hormone and/or methyl farnesoate in spiders.
Topics: Animals; Female; Juvenile Hormones; Male; Metamorphosis, Biological; Phylogeny; Spiders; Vitellogenesis
PubMed: 33862048
DOI: 10.1016/j.ygcen.2021.113781 -
Tropical Biomedicine Sep 2021Juvenile hormone is an exclusive hormone found in insects which involves regulating various insect physiology. A total of eight juvenile hormones have been identified in... (Review)
Review
Juvenile hormone is an exclusive hormone found in insects which involves regulating various insect physiology. A total of eight juvenile hormones have been identified in insects which include JH 0, JH I, JH II, JH III, 4-methyl JH I (Iso- JH 0), JHB III, JHSB III, and MF. Corpora allata are the glands responsible for the production and synthesis of these hormones. They are involved in moulting, reproduction, polyethism, and behavioural regulations in different orders of insects. Factors such as diet temperatures, photoperiods, and plant compounds affect the biosynthesis and regulation of juvenile hormones. Juvenile hormones analogue is usually used to disrupt normal regulation of JH and this analogue is categorized as insect-growth regulators (IGRs) and is widely used in pest control as an alternative to chemical insecticides. Other applications of biosynthesis activities of this hormone have not been explored in the area of JHs. In this review, current applications of JHs with an addition of their future application will be discussed.
Topics: Animals; Corpora Allata; Insecta; Juvenile Hormones; Molting; Pest Control
PubMed: 34362868
DOI: 10.47665/tb.38.3.066 -
General and Comparative Endocrinology Sep 2020The sesquiterpenoid juvenile hormone(s) (JHs) of insects are the primary regulators of growth, metamorphosis, and reproduction in most insect species. As a consequence,... (Review)
Review
The sesquiterpenoid juvenile hormone(s) (JHs) of insects are the primary regulators of growth, metamorphosis, and reproduction in most insect species. As a consequence, it is essential that JH production be precisely regulated so that it is present only during appropriate periods necessary for the control of these processes. The presence of JH at inappropriate times results in disruption to metamorphosis and development and, in some cases, to disturbances in female reproduction. Neuropeptides regulate the timing and production of JH by the corpora allata. Allatostatin and allatotropin were the names coined for neuropeptides that serve as inhibitors or stimulators of JH biosynthesis, respectively. Three different allatostatin neuropeptide families are capable of inhibiting juvenile hormone but only one family is utilized for that purpose dependent on the insect studied. The function of allatotropin also varies in different insects. These neuropeptides are pleiotropic in function acting on diverse physiological processes in different insects such as muscle contraction, sleep and neuromodulation. Genome projects and expression studies have assigned individual neuropeptide families to their respective receptors. An understanding of the localization of these receptors is providing clues as to how numerous peptide families might be integrated in regulating physiological functions. In recent years microRNAs have been identified that down-regulate enzymes and transcription factors that are involved in the biosynthesis and action of juvenile hormone.
Topics: Amino Acid Sequence; Animals; Evolution, Molecular; Insect Hormones; Juvenile Hormones; MicroRNAs; Neuropeptides
PubMed: 32413346
DOI: 10.1016/j.ygcen.2020.113507 -
Current Opinion in Insect Science Feb 2018Many insects have the ability to develop alternative morphologies in response to specific environmental signals such as photoperiod, temperature, nutrition and crowding.... (Review)
Review
Many insects have the ability to develop alternative morphologies in response to specific environmental signals such as photoperiod, temperature, nutrition and crowding. These signals are integrated by the brain and result in alternative patterns of secretion of developmental hormones like ecdysone, juvenile hormone and insulin-like growth factors, which, in turn, direct alternative developmental trajectories. Insulin signaling appears to be particularly important when the polyphenism involves differences in the sizes of the body, appendages and other structures, such as wings, mandibles and horns. Here we review recent advances in understanding the role of insulin signaling, and its interaction with other hormones, in the development of polyphenisms.
Topics: Animals; Ecdysone; Insecta; Insulin; Juvenile Hormones; Phenotype; Signal Transduction; Somatomedins
PubMed: 29602363
DOI: 10.1016/j.cois.2017.11.011 -
Cells Jan 2023NUMB, a plasma membrane-associated protein originally described in , is involved in determining cell function and fate during early stages of development. It is secreted... (Review)
Review
NUMB, a plasma membrane-associated protein originally described in , is involved in determining cell function and fate during early stages of development. It is secreted asymmetrically in dividing cells, with one daughter cell inheriting NUMB and the other inheriting its antagonist, NOTCH. NUMB has been proposed as a polarizing agent and has multiple functions, including endocytosis and serving as an adaptor in various cellular pathways such as NOTCH, Hedgehog, and the P53-MDM2 axis. Due to its role in maintaining cellular homeostasis, it has been suggested that NUMB may be involved in various human pathologies such as cancer and Alzheimer's disease. Further research on NUMB could aid in understanding disease mechanisms and advancing the field of personalized medicine and the development of new therapies.
Topics: Animals; Humans; Drosophila Proteins; Receptors, Notch; Drosophila; Membrane Proteins; Nerve Tissue Proteins; Juvenile Hormones
PubMed: 36672267
DOI: 10.3390/cells12020333 -
Current Opinion in Insect Science Feb 2021Proper formation of adult insects requires the integration of spatial and temporal regulatory axes. Whereas spatial information confers identity to each tissue, organ... (Review)
Review
Proper formation of adult insects requires the integration of spatial and temporal regulatory axes. Whereas spatial information confers identity to each tissue, organ and appendage, temporal information specifies at which stage of development the animal is. Regardless of the type of post-embryonic development, either hemimetabolous or holometabolous, temporal specificity is achieved through interactions between the temporal identity genes Kr-h1, E93 and Br-C, whose sequential expression is controlled by the two major developmental hormones, 20-hydroxyecdysone and Juvenile hormone. Given the intimate regulatory connection between these three factors to specify life stage identity, we dubbed the regulatory axis that comprises these genes as the Metamorphic Gene Network (MGN). In this review, we survey the molecular mechanisms underlying the control by the MGN of stage identity and progression in hemimetabolous and holometabolous insects.
Topics: Animals; Ecdysterone; Gene Expression Regulation, Developmental; Gene Regulatory Networks; Insecta; Juvenile Hormones; Metamorphosis, Biological
PubMed: 33075581
DOI: 10.1016/j.cois.2020.10.002 -
Insect Science Aug 2019Since it was first postulated by Wigglesworth in 1934, juvenile hormone (JH) is considered a status quo hormone in insects because it prevents metamorphosis that is... (Review)
Review
Since it was first postulated by Wigglesworth in 1934, juvenile hormone (JH) is considered a status quo hormone in insects because it prevents metamorphosis that is initiated by the molting hormone 20-hydroxyecdysone (20E). During the last decade, significant advances have been made regarding JH signaling. First, the bHLH-PAS transcription factor Met/Gce was identified as the JH intracellular receptor. In the presence of JH, with the assistance of Hsp83, and through physical association with a bHLH-PAS transcriptional co-activator, Met/Gce enters the nucleus and binds to E-box-like motifs in promoter regions of JH primary-response genes for inducing gene expression. Second, the zinc finger transcription factor Kr-h1 was identified as the anti-metamorphic factor which transduces JH signaling. Via Kr-h1 binding sites, Kr-h1 represses expression of 20E primary-response genes (i.e. Br, E93 and E75) to prevent 20E-induced metamorphosis. Third, through the intracellular signaling, JH promotes different aspects of female reproduction. Nevertheless, this action varies greatly from species to species. Last, a hypothetical JH membrane receptor has been predicted to be either a GPCR or a tyrosine kinase receptor. In future, it will be a great challenge to understand how the JH intracellular receptor Met/Gce and the yet unidentified JH membrane receptor coordinate to regulate metamorphosis and reproduction in insects.
Topics: Animals; Fatty Acids, Unsaturated; Insecta; Juvenile Hormones; Metamorphosis, Biological; Receptors, Cell Surface; Reproduction; Second Messenger Systems
PubMed: 29888456
DOI: 10.1111/1744-7917.12614 -
PLoS Genetics Sep 2023TAIMAN (TAI), the only insect ortholog of mammalian Steroid Receptor Coactivators (SRCs), is a critical modulator of ecdysone and juvenile hormone (JH) signaling...
TAIMAN (TAI), the only insect ortholog of mammalian Steroid Receptor Coactivators (SRCs), is a critical modulator of ecdysone and juvenile hormone (JH) signaling pathways, which govern insect development and reproduction. The modulatory effect is mediated by JH-dependent TAI's heterodimerization with JH receptor Methoprene-tolerant and association with the Ecdysone Receptor complex. Insect hormones regulate insect physiology and development in concert with abiotic cues, such as photo- and thermoperiod. Here we tested the effects of JH and ecdysone signaling on the circadian clock by a combination of microsurgical operations, application of hormones and hormone mimics, and gene knockdowns in the linden bug Pyrrhocoris apterus males. Silencing taiman by each of three non-overlapping double-strand RNA fragments dramatically slowed the free-running period (FRP) to 27-29 hours, contrasting to 24 hours in controls. To further corroborate TAIMAN's clock modulatory function in the insect circadian clock, we performed taiman knockdown in the cockroach Blattella germanica. Although Blattella and Pyrrhocoris lineages separated ~380 mya, B. germanica taiman silencing slowed the FRP by more than 2 hours, suggesting a conserved TAI clock function in (at least) some insect groups. Interestingly, the pace of the linden bug circadian clock was neither changed by blocking JH and ecdysone synthesis, by application of the hormones or their mimics nor by the knockdown of corresponding hormone receptors. Our results promote TAI as a new circadian clock modulator, a role described for the first time in insects. We speculate that TAI participation in the clock is congruent with the mammalian SRC-2 role in orchestrating metabolism and circadian rhythms, and that TAI/SRCs might be conserved components of the circadian clock in animals.
Topics: Animals; Male; Circadian Clocks; Ecdysone; Insecta; Circadian Rhythm; Cell Membrane; Juvenile Hormones; Mammals
PubMed: 37683015
DOI: 10.1371/journal.pgen.1010924 -
International Journal of Molecular... May 2022The sesquiterpenoid hormone juvenile hormone (JH) controls development, reproduction, and metamorphosis in insects, and has long been thought to be confined to the...
The sesquiterpenoid hormone juvenile hormone (JH) controls development, reproduction, and metamorphosis in insects, and has long been thought to be confined to the Insecta. While it remains true that juvenile hormone is specifically synthesized in insects, other types or forms of sesquiterpenoids have also been discovered in distantly related animals, such as the jellyfish. Here, we combine the latest literature and annotate the sesquiterpenoid biosynthetic pathway genes in different animal genomes. We hypothesize that the sesquiterpenoid hormonal system is an ancestral system established in an animal ancestor and remains widespread in many animals. Different animal lineages have adapted different enzymatic routes from a common pathway, with cnidarians producing farnesoic acid (FA); non-insect protostomes and non-vertebrate deuterostomes such as cephalochordate and echinoderm synthesizing FA and methyl farnesoate (MF); and insects producing FA, MF, and JH. Our hypothesis revolutionizes the current view on the sesquiterpenoids in the metazoans, and forms a foundation for a re-investigation of the roles of this important and yet neglected type of hormone in different animals.
Topics: Animals; Biosynthetic Pathways; Insecta; Juvenile Hormones; Metamorphosis, Biological; Sesquiterpenes
PubMed: 35682678
DOI: 10.3390/ijms23115998