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Sample records for juvenile hormone influence

  1. THE INFLUENCE OF INSECT JUVENILE HORMONE AGONISTTS ON METAMORPHOSIS AND REPRODUCTION IN ESTUARINE CRUSTACEANS

    EPA Science Inventory

    Comparative developmental and reproductive studies were performed on several species of estuarine crustaceans in response to three juvenile hormone agonists (JHAs) (methoprene, fenoxycarb, and pyriproxyfen). Larval development of the grass shrimp, Palaemonetes pugio, was greater ...

  2. The influence of insect juvenile hormone agonists on metamorphosis and reproduction in estuarine crustaceans.

    PubMed

    McKenney, Charles L

    2005-01-01

    Comparative developmental and reproductive studies were performed on several species of estuarine crustaceans in response to three juvenile hormone agonists (pyriproxyfen, methoprene and fenoxycarb). Larval development of the grass shrimp, Palaemonetes pugio, was greater than two orders of magnitude more sensitive to disruption by methoprene and fenoxycarb than was embryonic development. Developing larvae of the mud crab, Rhithropanopeus harrisii, exhibited reduced metamorphic success at lower concentrations of methoprene and pyriproxyfen than grass shrimp larvae. These responses suggest that the more rigidly controlled metamorphic process in crabs is more sensitive to compounds acting as endocrine disruptors than is the more flexible metamorphic pattern in shrimp. The final crab larval stage, the megalopa, was more sensitive to methoprene and fenoxycarb exposure than earlier zoeal stages. Mud crab larvae exposed to fenoxycarb had reduced biomass and lipid content, particularly triglycerides and sterols. Concentrations of fenoxycarb which reduced the reproductive capacity in single life-cycle exposures of the estuarine mysid, Americamysis bahia, were similar to those concentrations which inhibited metamorphosis in grass shrimp. Juvenile mysids released by exposed adults and reared through maturation without further exposure produced fewer young and had altered sex ratios (lower percentages of males) at lower parental-exposure concentrations than directly affected parental reproduction. These transgenerational responses may well be a product of irreversible effects during developmental exposures which become apparent following maturation and initiation of reproduction. These findings support using a functional approach as an appropriate screening procedure to evaluate potential environmental endocrine-disrupting chemicals in aquatic environments.

  3. Influence of juvenile hormone and mating on oogenesis and oviposition in the codling moth, cydia pomonella

    PubMed

    Webb; Shu; Ramaswamy; Dorn

    1999-01-01

    Oogenesis in the codling moth, Cydia pomonella, and the role of juvenile hormones (JHs) were addressed. Rudimentary ovarian structures were recognisable in day 3-4 pupae, when haemolymph JH was still undetectable by coupled gas chromatography-mass spectrometry in the selected ion mode (GC-MS/SIM). The presence of developing oocytes was observed by light microscopy on day 8, coincident with very low JH titres (0.74 +/- 0.05 ng/ml JH II). Chorionation was only evident upon emergence, following an increase in JH in the pharate adult (0h old: 4.71 +/- 0.34 ng/ml JH II). Analysis of haemolymph from virgin and mated females indicated that JH II was predominant, with approximately equal and lower quantities of JHs I and III (3.3- to 5.0-fold less). When pupae or newly emerged adults were treated with JH homologues, no alteration in ovarian protein content was apparent, but the JH mimetic, fenoxycarb, depressed the number of oocytes filling >/= 50% follicular volume. Chorion deposition was stimulated by JHs I, II, or III (10 &mgr;g), but not by fenoxycarb (0.05 &mgr;g, 10 &mgr;g). Mating provided correct stimuli for enhanced choriogenesis and egg laying, and, since haemolymph JH titres were concomitantly elevated (approximately 2-fold), it was postulated that the rise in JH elicited both these events. Application of JHs to virgin females, however, could not mimic mating; only increases in choriogenesis were induced: JH-treatment of virgins (or mated insects) significantly decreased oviposition rates over 24 and 48 h and markedly reduced the life-time total number of eggs. Arch. Copyright 1999 Wiley-Liss, Inc.

  4. Light exposure leads to reorganization of microglomeruli in the mushroom bodies and influences juvenile hormone levels in the honeybee.

    PubMed

    Scholl, Christina; Wang, Ying; Krischke, Markus; Mueller, Martin J; Amdam, Gro V; Rössler, Wolfgang

    2014-11-01

    Honeybees show a remarkable behavioral plasticity at the transition from nursing inside the hive to foraging for nectar and/or pollen outside. This plasticity is important for age-related division of labor in honeybee colonies. The behavioral transition is associated with significant volume and synaptic changes in the mushroom bodies (MBs), brain centers for sensory integration, learning, and memory. We tested whether precocious sensory exposure to light leads to changes in the density of synaptic complexes [microglomeruli (MG)] in the MBs. The results show that exposure to light pulses over 3 days induces a significant decrease in the MG density in visual subregions (collar) of the MB. Earlier studies had shown that foragers have increased levels of juvenile hormone (JH) co-occurring with a decrease of vitellogenin (Vg). Previous work further established that RNAi-mediated knockdown of vg and ultraspiracle (usp) induced an upregulation of JH levels, which can lead to precocious foraging. By disturbing both Vg and JH pathways using gene knockdown of vg and usp, we tested whether the changes in the hormonal system directly affect MG densities. Our study shows that MG numbers remained unchanged when Vg and JH pathways were perturbed, suggesting no direct hormonal influences on MG densities. However, mass spectrometry detection of JH revealed that precocious light exposure triggered an increase in JH levels in the hemolymph (HL) of young bees. This suggests a dual effect following light exposure via direct effects on MG reorganization in the MB calyx and a possible positive feedback on HL JH levels.

  5. Juvenile hormone regulation of Drosophila aging

    PubMed Central

    2013-01-01

    Background Juvenile hormone (JH) has been demonstrated to control adult lifespan in a number of non-model insects where surgical removal of the corpora allata eliminates the hormone’s source. In contrast, little is known about how juvenile hormone affects adult Drosophila melanogaster. Previous work suggests that insulin signaling may modulate Drosophila aging in part through its impact on juvenile hormone titer, but no data yet address whether reduction of juvenile hormone is sufficient to control Drosophila life span. Here we adapt a genetic approach to knock out the corpora allata in adult Drosophila melanogaster and characterize adult life history phenotypes produced by reduction of juvenile hormone. With this system we test potential explanations for how juvenile hormone modulates aging. Results A tissue specific driver inducing an inhibitor of a protein phosphatase was used to ablate the corpora allata while permitting normal development of adult flies. Corpora allata knockout adults had greatly reduced fecundity, inhibited oogenesis, impaired adult fat body development and extended lifespan. Treating these adults with the juvenile hormone analog methoprene restored all traits toward wildtype. Knockout females remained relatively long-lived even when crossed into a genotype that blocked all egg production. Dietary restriction further extended the lifespan of knockout females. In an analysis of expression profiles of knockout females in fertile and sterile backgrounds, about 100 genes changed in response to loss of juvenile hormone independent of reproductive state. Conclusions Reduced juvenile hormone alone is sufficient to extend the lifespan of Drosophila melanogaster. Reduced juvenile hormone limits reproduction by inhibiting the production of yolked eggs, and this may arise because juvenile hormone is required for the post-eclosion development of the vitellogenin-producing adult fat body. Our data do not support a mechanism for juvenile hormone control

  6. Influence of age and juvenile hormone on brain dopamine level in male honeybee (Apis mellifera): association with reproductive maturation.

    PubMed

    Harano, Ken-ichi; Sasaki, Ken; Nagao, Takashi; Sasaki, Masami

    2008-05-01

    Dopamine (DA) is a major functional biogenic amine in insects and has been suggested to regulate reproduction in female honeybees. However, its function has not been investigated in male drones. To clarify developmental changes of DA in drones, brain DA levels were investigated at various ages and showed a similar pattern to the previously reported juvenile hormone (JH) hemolymph titer. The DA level was lowest at emergence and peaked at day 7 or 8, followed by decline. Application of JH analog increased brain DA levels in young drones (2-4-days-old), suggesting regulation of DA by JH in drones. In young drones, maturation of male reproductive organs closely matched the increase in brain DA. The dry weight of testes decreased and that of seminal vesicles increased from emergence to day 8. The dry weight of mucus glands increased up to day 4. Consequently, DA regulated by JH might have reproductive behavior and/or physiological functions in drones.

  7. Behavioural effects of juvenile hormone and their influence on division of labour in leaf-cutting ant societies.

    PubMed

    Norman, Victoria C; Hughes, William O H

    2016-01-01

    Division of labour in social insects represents a major evolutionary transition, but the physiological mechanisms that regulate this are still little understood. Experimental work with honey bees, and correlational analyses in other social insects, have implicated juvenile hormone (JH) as a regulatory factor, but direct experimental evidence of behavioural effects of JH in social insects is generally lacking. Here, we used experimental manipulation of JH to show that raised JH levels in leaf-cutting ants results in workers becoming more active, phototactic and threat responsive, and engaging in more extranidal activity - behavioural changes that we show are all characteristic of the transition from intranidal work to foraging. These behavioural effects on division of labour suggest that the JH mediation of behaviour occurs across multiple independent evolutions of eusociality, and may be a key endocrine regulator of the division of labour which has produced the remarkable ecological and evolutionary success of social insects.

  8. Seasonal changes in juvenile hormone titers and rates of biosynthesis in honey bees.

    PubMed

    Huang, Z Y; Robinson, G E

    1995-01-01

    Honey bee colonies can respond to changing environmental conditions by showing plasticity in age related division of labor, and these responses are associated with changes in juvenile hormone. The shift from nest tasks to foraging has been especially well characterized; foraging is associated with high juvenile hormone titers and high rates of juvenile hormone biosynthesis, and can be induced prematurely in young bees by juvenile hormone treatment or by a shortage of foragers. However, very few studies have been conducted that study plasticity in division of labor under naturally occurring changes in the environment. To gain further insight into how the environment and juvenile hormone influence foraging behavior, we measured juvenile hormone titers and rates of biosynthesis in workers during times of the year when colony activity in temperature climates is reduced: late fall, winter, and early spring. Juvenile hormone titers and rates of biosynthesis decreased in foragers in the fall as foraging diminished and bees became less active. This demonstration of a natural drop in juvenile hormone confirms and extends previous findings when bees were experimentally induced to revert from foraging to within-hive tasks. In addition, endocrine changes in foragers in the fall are part of a larger seasonally related phenomenon in which juvenile hormone levels in younger, pre-foraging bees also decline in the fall and then increase the following spring as colony activity increases. The seasonal decline in juvenile hormone in foragers was mimicked in summer by placing a honey bee colony in a cold room for 8 days. This suggests that seasonal changes in juvenile hormone are not related to photoperiod changes, but rather to changes in temperature and/or colony social structure that in turn influence endocrine and behavioral development. We also found that active foragers in the late winter and early spring had lower juvenile hormone levels than active foragers in late spring. In

  9. Seasonal variation in plasma thyroid hormone concentrations in coastal versus inland populations of juvenile American alligators (Alligator mississippiensis): influence of plasma iodide concentrations.

    PubMed

    Boggs, Ashley S P; Hamlin, Heather J; Lowers, Russell H; Guillette, Louis J

    2011-12-01

    Thyroid hormones, essential for normal growth and health, are associated with changes in temperature, photoperiod, and reproduction. Iodide, a necessary element for thyroid hormone production, varies in diet, and is more abundant in estuarine environments, which could alter thyroid hormone variation. However, associations between thyroid hormone concentrations in animals from marine versus freshwater environments, which could become more pertinent with rising sea levels associated with global climate change, are not well studied. To determine the importance of dietary iodide in seasonal variation of plasma thyroid hormone concentrations, we analyzed seasonal variation of plasma thyroxine (T(4)) and triiodothyronine (T(3)) concentrations in juvenile alligators from an estuarine habitat (Merritt Island National Wildlife Refuge; MI) and a freshwater habitat (Lake Woodruff National Wildlife Refuge; LW) and compared these results to plasma inorganic iodide (PII) concentrations. Alligators from MI did not display seasonal variation in plasma T(4), but exhibited a seasonal pattern in plasma T(3) concentrations similar to alligators from LW. Plasma thyroid hormone concentrations were consistently higher at MI than at LW. PII concentrations were correlated with plasma T(4) and T(3) concentrations in juvenile alligators from LW but not MI. The data on plasma T(4) and T(3) concentrations suggest altered iodide metabolism in estuarine alligators. Differences in thyroid hormone concentrations between the populations could be due to differences in dietary iodide, which need to be further evaluated.

  10. Juvenile hormone esterase: biochemistry and structure

    PubMed Central

    Kamita, Shizuo G.; Hammock, Bruce D.

    2013-01-01

    Synopsis Normal insect development requires a precisely timed, precipitous drop in hemolymph juvenile hormone (JH) titer. This drop occurs through a coordinated halt in JH biosynthesis and increase in JH metabolism. In many species, JH esterase (JHE) is critical for metabolism of the resonance-stabilized methyl ester of JH. JHE metabolizes JH with a high kcat/KM ratio that results primarily from an exceptionally low KM. Here we review the biochemistry and structure of authentic and recombinant JHEs from six insect orders, and present updated diagnostic criteria that help to distinguish JHEs from other carboxylesterases. The use of a JHE-encoding gene to improve the insecticidal efficacy of biopesticides is also discussed. PMID:23543805

  11. Aedes aegypti juvenile hormone acid methyl transferase, the ultimate enzyme in the biosynthetic pathway of juvenile hormone III, exhibits substrate control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report on the cloning, sequencing, characterization, 3D modeling and docking of Aedes aegypti juvenile hormone acid methyl transferase (AeaJHAMT), the enzyme that converts juvenile hormone acid (JHA) into juvenile hormone (JH). Purified recombinant AeaJHAMT was extensively characterized for enzym...

  12. Juvenile hormone regulation of longevity in the migratory monarch butterfly.

    PubMed

    Herman, W S; Tatar, M

    2001-12-22

    Monarch butterflies (Danaus plexippus) of eastern North America are well known for their long-range migration to overwintering roosts in south-central Mexico. An essential feature of this migration involves the exceptional longevity of the migrant adults; individuals persist from August/September to March while their summer counterparts are likely to live less than two months as adults. Migrant adults persist during a state of reproductive diapause in which both male and female reproductive development is arrested as a consequence of suppressed synthesis of juvenile hormone. Here, we describe survival in monarch butterflies as a function of the migrant syndrome. We show that migrant adults are longer lived than summer adults when each are maintained under standard laboratory conditions, that the longevity of migrant adults is curtailed by treatment with juvenile hormone and that the longevity of summer adults is increased by 100% when juvenile hormone synthesis is prevented by surgical removal of its source, the corpora allatum. Thus, monarch butterfly persistence through a long winter season is ensured in part by reduced ageing that is under endocrine regulation, as well as by the unique environmental properties of their winter roost sites. Phenotypic plasticity for ageing is an integral component of the monarch butterflies' migration-diapause syndrome.

  13. Juvenile hormone agonists affect the occurrence of male Daphnia.

    PubMed

    Tatarazako, Norihisa; Oda, Shigeto; Watanabe, Hajime; Morita, Masatoshi; Iguchi, Taisen

    2003-12-01

    The water flea Daphnia magna reproduces primarily by cyclic parthenogenesis. Environmental stimuli that signal a change to adverse conditions induce the organisms to switch from parthenogenesis to gamogenetic reproduction. During the gamogenetic period, they produce male daphnids and dormant resting eggs, which can survive prolonged periods of environmental adversity. However, little is known about the mechanisms associated with the switch from parthenogenesis to gamogenetic reproduction. We investigated the effects of several juvenoids on sex determination in Daphnia. Females less than 24 h old were exposed to various concentrations of the test substance and were observed for 21 days. It was found that they can trigger the appearance of male daphnids: the percentage of males in the population increases to a level greater than what occurs under ordinary environmental conditions. We found that methylfarnesoate, juvenile hormone III, methoprene, and the phenoxyphenoxy derivatives pyriproxyfen and fenoxycarb (both insecticides) reduced the production of offspring and produced sex ratios dominated by male daphnids. Pyriproxyfen and fenoxycarb showed striking effects at low concentrations. Exposure to either of these chemicals at a concentration of 330 ngl(-1) caused adult females to produce almost all male neonates. Methylfarnesoate, juvenile hormone III, and methoprene showed an effect in inducing male production at higher concentrations (3.7 x 10(3), 3.3 x 10(5), and 1.3 x 10(5) ngl(-1), respectively). Our findings suggest that juvenile hormone agonists, including some insecticides, affect the chemical signaling responsible for inducing the production of male offspring.

  14. Larval feeding substrate and species significantly influence the effect of a juvenile hormone analog on sexual development/performance in four tropical tephritid flies.

    PubMed

    Aluja, Martín; Ordano, Mariano; Teal, Peter E A; Sivinski, John; García-Medel, Darío; Anzures-Dadda, Alberto

    2009-03-01

    The juvenile hormone (JH) analog methoprene reduces the amount of time it takes laboratory-reared Anastrepha suspensa (Caribbean fruit fly) males to reach sexual maturity by almost half. Here, we examined if methoprene exerted a similar effect on four other tropical Anastrepha species (Anastrepha ludens, Anastrepha obliqua, Anastrepha serpentina and Anastrepha striata) reared on natural hosts and exhibiting contrasting life histories. In the case of A. ludens, we worked with two populations that derived from Casimiroa greggii (ancestral host, larvae feed on seeds) and Citrus paradisi (exotic host, larvae feed on pulp). We found that the effects of methoprene, when they occurred, varied according to species and, in the case of A. ludens, according to larval host. For example, in the case of the two A. ludens populations the effect of methoprene on first appearance of male calling behavior and number of copulations was only apparent in flies derived from C. greggii. In contrast, males derived from C. paradisi called and mated almost twice as often and females started to lay eggs almost 1 day earlier than individuals derived from C. greggii, but in this case there was no significant effect of treatment (methoprene) only a significant host effect. There were also significant host and host by treatment interactions with respect to egg clutch size. A. ludens females derived from C. paradisi laid significantly more eggs per clutch and total number of eggs than females derived from C. greggii. With respect to the multiple species comparisons, the treatment effect was consistent for A. ludens, occasional in A. serpentina (e.g., calling by males, clutch size), and not apparent in the cases of A. obliqua and A. striata. Interestingly, with respect to clutch size, in the cases of A. ludens and A. serpentina, the treatment effect followed opposite directions: positive in the case of A. ludens and negative in the case of A. serpentina. We center our discussion on two hypotheses

  15. Juvenile Hormone Titer Versus Juvenile Hormone Synthesis in Female Nymphs and Adults of the German Cockroach, Blattella germanica

    PubMed Central

    Treiblmayr, Karl; Pascual, Nuria; Piulachs, Maria-Dolors; Keller, Thomas; Belles, Xavier

    2006-01-01

    Patterns of juvenile hormone have been intensively studied in the cockroach Blattella germanica under different physiological situations. However, data have been mainly obtained in vitro, and refer to hormone synthesized by isolated corpora allata, whereas information available on hormone concentration in the hemolymph is restricted to adult females. In order to complement our studies in vitro, we have measured juvenile hormone titer in the hemolymph of B. germanica females in four characteristic physiological situations: penultimate and last instar nymphs, adults during the first vitellogenic cycle, and adults transporting egg cases (ootheca). In general, a significant positive correlation between rates of hormone synthesis and concentration in the hemolymph is observed. The main disparities appear in the penultimate day of the period of ootheca transport, where titer is high whereas synthesis is low, and on day 6 of the first vitellogenic cycle, where synthesis increases whereas titer decreases. At these stages, the observed disparities between synthesis and titer might be explained by differential action of degradation enzymes. PMID:20233097

  16. Modeling resistance to juvenile hormone analogs: linking evolution, ecology and management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Juvenile hormone analogs (JHAs) are insecticides that mimic insect juvenile hormone and interfere with normal insect development. JHAs disrupt a hormonal system that is specific to insects and thus kill some target pests while causing little or no harm to most non-target organisms. Because of thei...

  17. The effects of juvenile hormone on Lasius niger reproduction.

    PubMed

    Pamminger, T; Buttstedt, A; Norman, V; Schierhorn, A; Botías, C; Jones, J C; Basley, K; Hughes, W O H

    2016-12-01

    Reproduction has been shown to be costly for survival in a wide diversity of taxa. The resulting trade-off, termed the reproduction-survival trade-off, is thought to be one of the most fundamental forces of life-history evolution. In insects the pleiotropic effect of juvenile hormone (JH), antagonistically regulating reproduction and pathogen resistance, is suggested to underlie this phenomenon. In contrast to the majority of insects, reproductive individuals in many eusocial insects defy this trade-off and live both long and prosper. By remodelling the gonadotropic effects of JH in reproductive regulation, the queens of the long-lived black garden ant Lasius niger (living up to 27 years), have circumvented the reproduction-survival trade off enabling them to maximize both reproduction and pathogen resistance simultaneously. In this study we measure fertility, vitellogenin gene expression and protein levels after experimental manipulation of hormone levels. We use these measurements to investigate the mechanistic basis of endocrinological role remodelling in reproduction and determine how JH suppresses reproduction in this species, rather then stimulating it, like in the majority of insects. We find that JH likely inhibits three key aspects of reproduction both during vitellogenesis and oogenesis, including two previously unknown mechanisms. In addition, we document that juvenile hormone, as in the majority of insects, has retained some stimulatory function in regulating vitellogenin expression. We discuss the evolutionary consequences of this complex regulatory architecture of reproduction in L. niger, which might enable the evolution of similar reproductive phenotypes by alternate regulatory pathways, and the surprising flexibility regulatory role of juvenile hormone in this process.

  18. Ecdysteroids, Juvenile Hormone and Vitellogenesis in the Cockroach Leucophaea maderae.

    PubMed Central

    Engelmann, Franz

    2002-01-01

    Topical application of 400µg of the juvenile hormone analog, methoprene, to females of the penultimate instar of Leucophaea maderae failed to induce vitellogenin synthesis. However, last instar females showed an increasing response level in making vitellogenin as they aged during the first half of the instar. In the second half of the last instar the response to methoprene declined to nearly zero when the prothoracic glands have become highly active. Then, a few days before the metamorphic molt the responsiveness reached maximal levels, i.e., comparable to adult females. These data suggest that the fat body develops competency to produce vitellogenin during the last nymphal instar, but increasing titers of ecdysone then interfere with the action of methoprene and consequently production of vitellogenin is curtailed. When prothoracic glands from the second half of the last instar were implanted into adult females, the normal activation of the corpora allata, or their accelerated activation induced by mating, did not occur. Likewise, an activation of the corpora allata due to the severance of the NCCI was not observed when prothoracic glands had been implanted prior to such operations. Thus, ecdysone released by the prothoracic glands appeared to directly inhibit the isolated corpora allata in vivo i.e. without the mediation by the brain. Methoprene applied to allatectomized adult females induced vitellogenin synthesis in a dose dependent manner. This induction was, however, quantitatively reduced by implanted active prothoracic glands, particularly when low doses of methoprene had been applied. Methoprene higher than 5µg overcame the inhibitory potency of the implanted prothoracic glands. The effect of the prothoracic glands, i.e. ecdysone, appears to signal an interference with the action of methoprene at the target tissues, the fat body. The exposure of the fat body to a given juvenile hormone/ecdysone ratio dictates the apparent effectiveness of ecdysone. The

  19. Vitellogenin, juvenile hormone, insulin signaling, and queen honey bee longevity

    PubMed Central

    Corona, Miguel; Velarde, Rodrigo A.; Remolina, Silvia; Moran-Lauter, Adrienne; Wang, Ying; Hughes, Kimberly A.; Robinson, Gene E.

    2007-01-01

    In most animals, longevity is achieved at the expense of fertility, but queen honey bees do not show this tradeoff. Queens are both long-lived and fertile, whereas workers, derived from the same genome, are both relatively short-lived and normally sterile. It has been suggested, on the basis of results from workers, that vitellogenin (Vg), best known as a yolk protein synthesized in the abdominal fat body, acts as an antioxidant to promote longevity in queen bees. We explored this hypothesis, as well as related roles of insulin–IGF-1 signaling and juvenile hormone. Vg was expressed in thorax and head fat body cells in an age-dependent manner, with old queens showing much higher expression than workers. In contrast, Vg expression in worker head was much lower. Queens also were more resistant to oxidative stress than workers. These results support the hypothesis that caste-specific differences in Vg expression are involved in queen longevity. Consistent with predictions from Drosophila, old queens had lower head expression of insulin-like peptide and its putative receptors than did old workers. Juvenile hormone affected the expression of Vg and insulin–IGF-1 signaling genes in opposite directions. These results suggest that conserved and species-specific mechanisms interact to regulate queen bee longevity without sacrificing fecundity. PMID:17438290

  20. Socially selected ornaments influence hormone titers of signalers and receivers

    PubMed Central

    Tibbetts, Elizabeth A.; Crocker, Katherine; Huang, Zachary Y.

    2016-01-01

    Decades of behavioral endocrinology research have shown that hormones and behavior have a bidirectional relationship; hormones both influence and respond to social behavior. In contrast, hormones are often thought to have a unidirectional relationship with ornaments. Hormones influence ornament development, but little empirical work has tested how ornaments influence hormones throughout life. Here, we experimentally alter a visual signal of fighting ability in Polistes dominulus paper wasps and measure the behavioral and hormonal consequences of signal alteration in signalers and receivers. We find wasps that signal inaccurately high fighting ability receive more aggression than controls and receiving aggression reduces juvenile hormone (JH) titers. As a result, immediately after contests, inaccurate signalers have lower JH titers than controls. Ornaments also directly influence rival JH titers. Three hours after contests, wasps who interacted with rivals signaling high fighting ability have higher JH titers than wasps who interacted with rivals signaling low fighting ability. Therefore, ornaments influence hormone titers of both signalers and receivers. We demonstrate that relationships between hormones and ornaments are flexible and bidirectional rather than static and unidirectional. Dynamic relationships among ornaments, behavior, and physiology may be an important, but overlooked factor in the evolution of honest communication. PMID:27402762

  1. How does juvenile hormone control insect metamorphosis and reproduction?

    PubMed

    Riddiford, Lynn M

    2012-12-01

    In insects juvenile hormone (JH) regulates both metamorphosis and reproduction. This lecture focuses on our current understanding of JH action at the molecular level in both of these processes based primarily on studies in the tobacco hornworm Manduca sexta, the flour beetle Tribolium castaneum, the mosquito Aedes aegypti, and the fruit fly Drosophila melanogaster. The roles of the JH receptor complex and the transcription factors that it regulates during larval molting and metamorphosis are summarized. Also highlighted are the intriguing interactions of the JH and insulin signaling pathways in both imaginal disc development and vitellogenesis. Critical actions of JH and its receptor in the timing of maturation of the adult optic lobe and of female receptivity in Drosophila are also discussed.

  2. Differential Juvenile Hormone Variations in Scale Insect Extreme Sexual Dimorphism.

    PubMed

    Vea, Isabelle Mifom; Tanaka, Sayumi; Shiotsuki, Takahiro; Jouraku, Akiya; Tanaka, Toshiharu; Minakuchi, Chieka

    2016-01-01

    Scale insects have evolved extreme sexual dimorphism, as demonstrated by sedentary juvenile-like females and ephemeral winged males. This dimorphism is established during the post-embryonic development; however, the underlying regulatory mechanisms have not yet been examined. We herein assessed the role of juvenile hormone (JH) on the diverging developmental pathways occurring in the male and female Japanese mealybug Planococcus kraunhiae (Kuwana). We provide, for the first time, detailed gene expression profiles related to JH signaling in scale insects. Prior to adult emergence, the transcript levels of JH acid O-methyltransferase, encoding a rate-limiting enzyme in JH biosynthesis, were higher in males than in females, suggesting that JH levels are higher in males. Furthermore, male quiescent pupal-like stages were associated with higher transcript levels of the JH receptor gene, Methoprene-tolerant and its co-activator taiman, as well as the JH early-response genes, Krüppel homolog 1 and broad. The exposure of male juveniles to an ectopic JH mimic prolonged the expression of Krüppel homolog 1 and broad, and delayed adult emergence by producing a supernumeral pupal stage. We propose that male wing development is first induced by up-regulated JH signaling compared to female expression pattern, but a decrease at the end of the prepupal stage is necessary for adult emergence, as evidenced by the JH mimic treatments. Furthermore, wing development seems linked to JH titers as JHM treatments on the pupal stage led to wing deformation. The female pedomorphic appearance was not reflected by the maintenance of high levels of JH. The results in this study suggest that differential variations in JH signaling may be responsible for sex-specific and radically different modes of metamorphosis.

  3. Differential Juvenile Hormone Variations in Scale Insect Extreme Sexual Dimorphism

    PubMed Central

    Vea, Isabelle Mifom; Tanaka, Sayumi; Shiotsuki, Takahiro; Jouraku, Akiya; Tanaka, Toshiharu; Minakuchi, Chieka

    2016-01-01

    Scale insects have evolved extreme sexual dimorphism, as demonstrated by sedentary juvenile-like females and ephemeral winged males. This dimorphism is established during the post-embryonic development; however, the underlying regulatory mechanisms have not yet been examined. We herein assessed the role of juvenile hormone (JH) on the diverging developmental pathways occurring in the male and female Japanese mealybug Planococcus kraunhiae (Kuwana). We provide, for the first time, detailed gene expression profiles related to JH signaling in scale insects. Prior to adult emergence, the transcript levels of JH acid O-methyltransferase, encoding a rate-limiting enzyme in JH biosynthesis, were higher in males than in females, suggesting that JH levels are higher in males. Furthermore, male quiescent pupal-like stages were associated with higher transcript levels of the JH receptor gene, Methoprene-tolerant and its co-activator taiman, as well as the JH early-response genes, Krüppel homolog 1 and broad. The exposure of male juveniles to an ectopic JH mimic prolonged the expression of Krüppel homolog 1 and broad, and delayed adult emergence by producing a supernumeral pupal stage. We propose that male wing development is first induced by up-regulated JH signaling compared to female expression pattern, but a decrease at the end of the prepupal stage is necessary for adult emergence, as evidenced by the JH mimic treatments. Furthermore, wing development seems linked to JH titers as JHM treatments on the pupal stage led to wing deformation. The female pedomorphic appearance was not reflected by the maintenance of high levels of JH. The results in this study suggest that differential variations in JH signaling may be responsible for sex-specific and radically different modes of metamorphosis. PMID:26894583

  4. Synthesis and binding affinity of an iodinated juvenile hormone

    SciTech Connect

    Prestwich, G.D.; Eng, W.S.; Robles, S.; Vogt, R.G.; Wisniewski, J.R.; Wawrzenczyk, C.

    1988-01-25

    The synthesis of the first iodinated juvenile hormone (JH) in enantiomerically enriched form is reported. This chiral compound, 12-iodo-JH I, has an iodine atom replacing a methyl group of the natural insect juvenile hormone, JH I, which is important in regulating morphogenesis and reproduction in the Lepidoptera. The unlabeled compound shows approximately 10% of the relative binding affinity for the larval hemolymph JH binding protein (JHBP) of Manduca sexta, which specifically binds natural /sup 3/H-10R,11S-JH I (labeled at 58 Ci/mmol) with a KD of 8 X 10(-8) M. It is also approximately one-tenth as biologically active as JH I in the black Manduca and epidermal commitment assays. The 12-hydroxy and 12-oxo compounds are poor competitors and are also biologically inactive. The radioiodinated (/sup 125/I)12-iodo-JH I can be prepared in low yield at greater than 2500 Ci/mmol by nucleophilic displacement using no-carrier-added /sup 125/I-labeled sodium iodide in acetone; however, synthesis using sodium iodide carrier to give the approximately 50 Ci/mmol radioiodinated ligand proceeds in higher radiochemical yield with fewer by-products and provides a radioligand which is more readily handled in binding assays. The KD of (/sup 125/I)12-iodo-JH I was determined for hemolymph JHBP of three insects: M. sexta, 795 nM; Galleria mellonella, 47 nM; Locusta migratoria, 77 nM. The selectivity of 12-iodo-JH I for the 32-kDa JHBP of M. sexta was demonstrated by direct autoradiography of a native polyacrylamide gel electrophoresis gel of larval hemolymph incubated with the radioiodinated ligand. Thus, the in vitro and in vivo activity of 12-iodo-JH I indicate that it can serve as an important new gamma-emitting probe in the search for JH receptor proteins in target tissues.

  5. Synthesis and binding affinity of an iodinated juvenile hormone.

    PubMed

    Prestwich, G D; Eng, W S; Robles, S; Vogt, R G; Wiśniewski, J R; Wawrzeńczyk, C

    1988-01-25

    The synthesis of the first iodinated juvenile hormone (JH) in enantiomerically enriched form is reported. This chiral compound, 12-iodo-JH I, has an iodine atom replacing a methyl group of the natural insect juvenile hormone, JH I, which is important in regulating morphogenesis and reproduction in the Lepidoptera. The unlabeled compound shows approximately 10% of the relative binding affinity for the larval hemolymph JH binding protein (JHBP) of Manduca sexta, which specifically binds natural 3H-10R,11S-JH I (labeled at 58 Ci/mmol) with a KD of 8 X 10(-8) M. It is also approximately one-tenth as biologically active as JH I in the black Manduca and epidermal commitment assays. The 12-hydroxy and 12-oxo compounds are poor competitors and are also biologically inactive. The radioiodinated [125I]12-iodo-JH I can be prepared in low yield at greater than 2500 Ci/mmol by nucleophilic displacement using no-carrier-added 125I-labeled sodium iodide in acetone; however, synthesis using sodium iodide carrier to give the approximately 50 Ci/mmol radioiodinated ligand proceeds in higher radiochemical yield with fewer by-products and provides a radioligand which is more readily handled in binding assays. The KD of [125I]12-iodo-JH I was determined for hemolymph JHBP of three insects: M. sexta, 795 nM; Galleria mellonella, 47 nM; Locusta migratoria, 77 nM. The selectivity of 12-iodo-JH I for the 32-kDa JHBP of M. sexta was demonstrated by direct autoradiography of a native polyacrylamide gel electrophoresis gel of larval hemolymph incubated with the radioiodinated ligand. Thus, the in vitro and in vivo activity of 12-iodo-JH I indicate that it can serve as an important new gamma-emitting probe in the search for JH receptor proteins in target tissues.

  6. TRANSGENERATIONAL EFFECTS OF A JUVENILE HORMONE MIMIC ON THE ESTUARINE MYSID, MYSIDOPSIS BAHIA (CRUSTACEA: MYSIDACEA)

    EPA Science Inventory

    Fenoxycarb is a juvenile hormone (JH) mimic used to control insect pests by interfering with reproductive and developmental processes mediated by JH. Crustaceans are ideal organisms to monitor environmental effects of these endocrine disruptors, since they are dominant aquatic ar...

  7. Sex-specific developmental profiles of juvenile hormone synthesis in honey bee larvae.

    PubMed

    Hartfelder, Klaus; de Oliveira Tozetto, Sibele; Rachinsky, Anna

    1993-02-01

    Juvenile hormone synthesis in drone larvae of the honey bee was measured by an in vitro radiochemical assay. The developmental profile of corpora allata activity in male larvae showed considerable differences from queen larvae, the presumptive reproductive females, and was comparable to workers, the sterile female morph. Drone and worker larvae, however, differed drastically in the regulation of juvenile hormone biosynthesis, as revealed by the addition of farnesoic acid to the culture medium. This precursor stimulated juvenile hormone synthesis of drone glands nearly eightfold, whereas in worker larvae it is known to lead to an accumulation of methyl farnesoate. The sex-specific differences in endocrine activity indicate a role for juvenile hormone in the expression of genetically determined sexually dimorphic characters during metamorphosis, a role not currently accounted for in models describing endocrine regulation of insect development.

  8. Biosynthesis of the Juvenile Hormones of Manduca sexta: Labeling Pattern from Mevalonate, Propionate, and Acetate

    PubMed Central

    Schooley, David A.; Judy, Kenneth J.; Bergot, B. John; Hall, M. Sharon; Siddall, John B.

    1973-01-01

    Using organ culture, high-resolution liquid chromatography, and microchemical techniques, we demonstrated the efficient incorporation in vitro of several radiolabeled precursors into the two juvenile hormones of Manduca sexta. JH II, a homosesquiterpene hormone, reported from M. sexta as well as several other insects, incorporates radiolabel from acetate, mevalonate, and propionate. JH III, a sesquiterpene hormone recently reported as a natural product of M. sexta, incorporates label from acetate and mevalonate, but not from propionate. Based on the position of the labeled atoms in the precursors and upon the position of incorporation obtained from label-distribution data, a scheme for juvenile hormone biosynthesis is advanced. PMID:16592112

  9. Ecdysis triggering hormone ensures proper timing of juvenile hormone biosynthesis in pharate adult mosquitoes.

    PubMed

    Areiza, Maria; Nouzova, Marcela; Rivera-Perez, Crisalejandra; Noriega, Fernando G

    2014-11-01

    Juvenile hormones (JHs) are synthesized by the corpora allata (CA) and play a key role in insect development. A decrease of JH titer in the last instar larvae allows pupation and metamorphosis to proceed. As the anti-metamorphic role of JH comes to an end, the CA of the late pupa (or pharate adult) becomes again "competent" to synthesize JH, which would play an essential role orchestrating reproductive maturation. In the present study, we provide evidence that ecdysis triggering hormone (ETH), a key endocrine factor involved in ecdysis control, acts as an allatotropic regulator of JH biosynthesis, controlling the exact timing of CA activation in the pharate adult mosquito. Analysis of the expression of Aedes aegypti ETH receptors (AeaETHRs) revealed that they are present in the CA and the corpora cardiaca (CC), and their expression peaks 4 h before eclosion. In vitro stimulation of the pupal CA glands with ETH resulted in an increase in JH synthesis. Consistent with this finding, silencing AeaETHRs by RNA interference (RNAi) in pupa resulted in reduced JH synthesis by the CA of one day-old adult females. Stimulation with ETH resulted in increases in the activity of juvenile hormone acid methyltransferase (JHAMT), a key JH biosynthetic enzyme. Furthermore, inhibition of IP3R-operated mobilization of endoplasmic reticulum Ca(2+) stores prevented the ETH-dependent increases of JH biosynthesis and JHAMT activity. All together these findings provide compelling evidence that ETH acts as a regulatory peptide that ensures proper developmental timing of JH synthesis in pharate adult mosquitoes.

  10. Molecular impact of juvenile hormone agonists on neonatal Daphnia magna.

    PubMed

    Toyota, Kenji; Kato, Yasuhiko; Miyakawa, Hitoshi; Yatsu, Ryohei; Mizutani, Takeshi; Ogino, Yukiko; Miyagawa, Shinichi; Watanabe, Hajime; Nishide, Hiroyo; Uchiyama, Ikuo; Tatarazako, Norihisa; Iguchi, Taisen

    2014-05-01

    Daphnia magna has been used extensively to evaluate organism- and population-level responses to pollutants in acute toxicity and reproductive toxicity tests. We have previously reported that exposure to juvenile hormone (JH) agonists results in a reduction of reproductive function and production of male offspring in a cyclic parthenogenesis, D. magna. Recent advances in molecular techniques have provided tools to understand better the responses to pollutants in aquatic organisms, including D. magna. DNA microarray was used to evaluate gene expression profiles of neonatal daphnids exposed to JH agonists: methoprene (125, 250 and 500 ppb), fenoxycarb (0.5, 1 and 2 ppb) and epofenonane (50, 100 and 200 ppb). Exposure to these JH analogs resulted in chemical-specific patterns of gene expression. The heat map analyses based on hierarchical clustering revealed a similar pattern between treatments with a high dose of methoprene and with epofenonane. In contrast, treatment with low to middle doses of methoprene resulted in similar profiles to fenoxycarb treatments. Hemoglobin and JH epoxide hydrolase genes were clustered as JH-responsive genes. These data suggest that fenoxycarb has high activity as a JH agonist, methoprene shows high toxicity and epofenonane works through a different mechanism compared with other JH analogs, agreeing with data of previously reported toxicity tests. In conclusion, D. magna DNA microarray is useful for the classification of JH analogs and identification of JH-responsive genes.

  11. Juvenile hormone and allatostatins in the German cockroach embryo.

    PubMed

    Maestro, José L; Pascual, Núria; Treiblmayr, Karl; Lozano, Jesús; Bellés, Xavier

    2010-09-01

    Levels of juvenile hormone III (JH), FGLamide allatostatin peptides (ASTs), ASTs precursor (preproAST) mRNA and methyl farnesoate epoxidase (CYP15A1) mRNA were measured in embryos of the cockroach Blattella germanica. JH starts to rise just after dorsal closure, reaches maximal levels between 60% and 80% of embryogenesis, and decrease subsequently to undetectable levels. ASTs show low levels during the first two thirds of embryogenesis, increase thereafter and maintain high levels until hatching. PreproAST mRNA shows quite high levels during the two days following oviposition, thus behaving as a maternal transcript, the levels then become very low until mid embryogenesis, and increase afterwards, peaking towards the end of embryo development. CYP15A1 transcripts were detected around 25% embryogenesis and the levels tended to increase through embryogenesis, although differences amongst the days studied were not statistically significant. The opposite patterns of JH and AST towards the end of embryo development, along with the detection of AST immunoreactivity in corpora allata from late embryos, suggest that JH decline is caused by the increase of AST. Moreover, the uncorrelated patterns of JH concentration and CYP15A1 mRNA levels suggest that CYP15A1 expression does not modulate JH production.

  12. Evolutionary Endocrinology of Hormonal Rhythms: Juvenile Hormone Titer Circadian Polymorphism in Gryllus firmus.

    PubMed

    Zera, Anthony J

    2016-08-01

    Daily rhythms for hormonal traits are likely widespread and important aspects of organismal (e.g., life history) adaptation. Yet they remain substantially understudied, especially with respect to variable rhythms within species. The cricket, Gryllus firmus, exhibits a genetically polymorphic circadian rhythm for the blood titer of the key hormone, juvenile hormone (JH). Gryllus firmus is also wing-polymorphic, consisting of a dispersing morph that delays reproduction and a flightless morph with substantially enhanced egg production. JH circadian phenotype strongly covaries with morph type: The blood JH titer is strongly rhythmic in multiple populations artificially-selected for the dispersing morph (LW(f) = long wings with functional flight muscles) and is essentially arrhythmic in populations selected for the SW (short-winged) morph. Association between JH titer cycle and LW(f) morph is also found in natural populations of G. firmus and in several related species in the field. This is one of the very few studies of endocrine titer variation in natural populations of an insect. The morph-specific cycle is underlain by a circadian rhythm in hormone biosynthesis, which in turn is underlain by a rhythm in a brain neuropeptide regulator of JH biosynthesis. The morph-specific JH titer circadian cycle is also strongly correlated with a morph-specific daily rhythm in global gene expression. This is currently the only example of a genetically-variable hormone circadian rhythm in both the laboratory and field that is strongly associated with an ecologically important polymorphism. The extensive information on the underlying causes of the morph-specific JH titer rhythm, coupled with the strong association between the JH circadian rhythm and wing polymorphism makes this system in G. firmus an exceptional experimental model to investigate the mechanisms underlying circadian hormonal adaptations. Genetic polymorphism for the JH titer circadian rhythm in G. firmus is discussed

  13. Microarray Analysis of Juvenile Hormone Response in Drosophila melanogaster S2 cells

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A microchip array encompassing probes for 14,010 genes of Drosophila melanogaster was used to analyze the effect of juvenile hormone (JH) on genome-wide gene expression. JH is a member of a key group of insect hormones involved in regulating larval development and adult reproductive processes. Altho...

  14. Spruce budworm (Choristoneura fumiferana) juvenile hormone esterase: hormonal regulation, developmental expression and cDNA cloning.

    PubMed

    Feng, Q L; Ladd, T R; Tomkins, B L; Sundaram, M; Sohi, S S; Retnakaran, A; Davey, K G; Palli, S R

    1999-02-25

    We have used the differential display of mRNAs technique to identify Choristoneura fumiferana genes that are induced by juvenile hormone I (JH I). Of the six PCR products identified, one bound to a 2.8-kb mRNA from CF-203 cells whose abundance increased when the cells were grown in the presence of JH I. The same 2.8-kb mRNA decreased to undetectable levels when the CF-203 cells were grown in the presence of 20-hydroxyecdysone (20E). The PCR fragment probe also detected a 2.8-kb mRNA in the C. fumiferana larval tissues. This 2.8-kb mRNA was present on the first day of the first, third, fourth, fifth and sixth larval and pupal stadia, but was conspicuously absent on the first day of the second larval stadium, as well as during the intermolt periods of the first to fifth instar larval stages. In the sixth instar larvae the 2.8-kb mRNA was detected in the fat body, epidermis and midgut during the intermolt period. The PCR fragment was used as a probe to screen a cDNA library. The deduced amino acid sequence of this 2.8-kb cDNA clone showed similarity with the deduced amino acid sequences of Heliothis virescens juvenile hormone esterases (HvJHE). The deduced amino acid sequence of the cDNA clone contained all five functional motifs that are present in most of esterases, proteases and lipases. The cDNA clone was expressed in the baculovirus expression system, producing a protein that showed JHE activity.

  15. Juvenile hormone regulates extreme mandible growth in male stag beetles.

    PubMed

    Gotoh, Hiroki; Cornette, Richard; Koshikawa, Shigeyuki; Okada, Yasukazu; Lavine, Laura Corley; Emlen, Douglas J; Miura, Toru

    2011-01-01

    The morphological diversity of insects is one of the most striking phenomena in biology. Evolutionary modifications to the relative sizes of body parts, including the evolution of traits with exaggerated proportions, are responsible for a vast range of body forms. Remarkable examples of an insect trait with exaggerated proportions are the mandibular weapons of stag beetles. Male stag beetles possess extremely enlarged mandibles which they use in combat with rival males over females. As with other sexually selected traits, stag beetle mandibles vary widely in size among males, and this variable growth results from differential larval nutrition. However, the mechanisms responsible for coupling nutrition with growth of stag beetle mandibles (or indeed any insect structure) remain largely unknown. Here, we demonstrate that during the development of male stag beetles (Cyclommatus metallifer), juvenile hormone (JH) titers are correlated with the extreme growth of an exaggerated weapon of sexual selection. We then investigate the putative role of JH in the development of the nutritionally-dependent, phenotypically plastic mandibles, by increasing hemolymph titers of JH with application of the JH analog fenoxycarb during larval and prepupal developmental periods. Increased JH signaling during the early prepupal period increased the proportional size of body parts, and this was especially pronounced in male mandibles, enhancing the exaggerated size of this trait. The direction of this response is consistent with the measured JH titers during this same period. Combined, our results support a role for JH in the nutrition-dependent regulation of extreme mandible growth in this species. In addition, they illuminate mechanisms underlying the evolution of trait proportion, the most salient feature of the evolutionary diversification of the insects.

  16. Production of male neonates in Daphnia magna (Cladocera, Crustacea) exposed to juvenile hormones and their analogs.

    PubMed

    Oda, Shigeto; Tatarazako, Norihisa; Watanabe, Hajime; Morita, Masatoshi; Iguchi, Taisen

    2005-12-01

    We exposed the water flea Daphnia magna (Cladocera, Crustacea) to either juvenile hormone I (JH I), juvenile hormone II (JH II), or the juvenile hormone-mimicking insecticides kinoprene, hydroprene, epofenonane, or fenoxycarb. By 21-day reproduction tests, we investigated the effects on the number of neonates born per female and the offspring sex ratio. All six chemicals induced D. magna to produce male neonates; the male sex ratio of the offspring increased as the chemical concentration increased. EC50 values for production of male neonates were estimated as 400 (JH I), 410 (JH II), 190 (kinoprene), 2.9 (hydroprene), 64 (epofenonane), and 0.92 (fenoxycarb) microg/l. The number of neonates produced was reduced with all chemicals at the concentrations investigated. At the EC50 for male production, five of the six chemicals reduced the reproductive rate to less than 50%; the exception was epofenonane, which caused only a slight reduction in reproductive rate. These results were similar to those obtained for five juvenoids studied previously, one of which was studied here again. There are now 10 chemical substances--all juvenile hormones or their analogs-that are known to induce D. magna to produce male neonates. This suggests that juvenile hormone is involved in initiating male production followed by sexual reproduction in D. magna, and probably in most cladocerans that exhibit cyclic parthenogenesis.

  17. Do hormones influence melanoma? Facts and controversies.

    PubMed

    Gupta, Amie; Driscoll, Marcia S

    2010-01-01

    The issue of whether hormones influence malignant melanoma (MM) has been controversial for many years. Although early case reports demonstrated a negative effect of hormones, recent evidence has not supported a potential role for hormones in MM. We address whether exogenous and endogenous hormones influence a woman's risk for MM or affect her prognosis if diagnosed with MM. Multiple epidemiologic studies show the use of oral contraceptives or hormone replacement therapy does not appear to increase a woman's risk for MM. Pregnancy does not appear to influence a woman's risk of MM, nor does pregnancy appear to affect prognosis in the woman diagnosed with MM. When counseling the woman who is diagnosed with MM during pregnancy or during the childbearing years, future use of oral contraceptives or hormone replacement therapy is not contraindicated; counseling concerning future pregnancies should be done on a case-by-case basis, with emphasis placed on established prognostic factors for MM.

  18. ISOLATION OF JUVENILE HORMONES ESTERASE AND ITS PARTIAL CDNA CLONE FROM THE BEETLE, TENEBRIO MOLITOR. (R825433)

    EPA Science Inventory

    Juvenile hormone esterase (JHE) plays an essential role in insect development. It is partially responsible for the clearance of juvenile hormone (JH) which regulates various aspects of insect development and reproduction. Because of its role in regulating JH titer, this enzyme...

  19. High specific activity enantiomerically enriched juvenile hormones: synthesis and binding assay.

    PubMed Central

    Prestwich, G D; Wawrzeńczyk, C

    1985-01-01

    A stereoselective total synthesis of chiral juvenile hormone I is described that allows stoichiometric introduction of two tritium atoms in the final step. Both optical antipodes of the pivotal epoxy alcohol intermediate were prepared in 95% enantiomeric excess by the Sharpless epoxidation of a (Z)-allylic alcohol. Elaboration of the hydroxy-methyl group to a vinyl group followed by selective homogeneous tritiation affords optically active juvenile hormone I analogs at 58 Ci/mmol. Competitive binding of the labeled 10R, 11S and 10S,11R enantiomers with unlabeled enantiomers to the hemolymph binding protein of Manduca sexta larvae was determined by using a dextran-coated charcoal assay. The natural 10R,11S enantiomer has twice the relative binding affinity of the 10S,11R enantiomer. The availability of such high specific activity optically pure hormones will contribute substantially to the search for high-affinity receptors for juvenile hormones in the nuclei of cells. Moreover, the chiral 12-hydroxy-(10R,11S)-epoxy intermediate allows modification of juvenile hormone for solid-phase biochemical and radioimmunochemical work without altering either the biologically important carbomethoxy or epoxy recognition sites. PMID:3860862

  20. High specific activity enantiomerically enriched juvenile hormones: synthesis and binding assay.

    PubMed

    Prestwich, G D; Wawrzeńczyk, C

    1985-08-01

    A stereoselective total synthesis of chiral juvenile hormone I is described that allows stoichiometric introduction of two tritium atoms in the final step. Both optical antipodes of the pivotal epoxy alcohol intermediate were prepared in 95% enantiomeric excess by the Sharpless epoxidation of a (Z)-allylic alcohol. Elaboration of the hydroxy-methyl group to a vinyl group followed by selective homogeneous tritiation affords optically active juvenile hormone I analogs at 58 Ci/mmol. Competitive binding of the labeled 10R, 11S and 10S,11R enantiomers with unlabeled enantiomers to the hemolymph binding protein of Manduca sexta larvae was determined by using a dextran-coated charcoal assay. The natural 10R,11S enantiomer has twice the relative binding affinity of the 10S,11R enantiomer. The availability of such high specific activity optically pure hormones will contribute substantially to the search for high-affinity receptors for juvenile hormones in the nuclei of cells. Moreover, the chiral 12-hydroxy-(10R,11S)-epoxy intermediate allows modification of juvenile hormone for solid-phase biochemical and radioimmunochemical work without altering either the biologically important carbomethoxy or epoxy recognition sites.

  1. Evolutionary Endocrinology of Juvenile Hormone Esterase in Gryllus Assimilis: Direct and Correlated Responses to Selection

    PubMed Central

    Zera, A. J.; Zhang, C.

    1995-01-01

    Hemolymph juvenile hormone esterase (JHE) activity on the third day of the last stadium in the cricket, Gryllus assimilis, exhibited a significant response to selection in each of six replicate lines. Mean realized heritability was 0.26 +/- 0.04. The response was due to changes in whole-organism enzyme activity as well as to changes in the proportion of enzyme allocated to the hemolymph compartment. In vivo juvenile hormone metabolism differed between some lines selected for high vs. low enzyme activity. Only minimal differences were observed between lines with respect to hemolymph protein concentration or whole-cricket activity of juvenile hormone epoxide hydrolase, the other major JH-degrading enzyme. Dramatic correlated responses to selection, equal in magnitude to the direct response, were observed for JHE activity on each of three other days of the last juvenile stadium. In contrast, no correlated responses in JHE activity were observed in adults. This indicates that JHE activities throughout the last stadium will evolve as a highly correlated unit independent of adult activities and the evolution of endocrine mechanisms regulating juvenile development can be decoupled from those controlling adult reproduction. This study represents the first quantitative-genetic analysis of naturally occurring endocrine variation in an insect species. PMID:8582618

  2. A Structural Equation Modeling Analysis of Influences on Juvenile Delinquency

    ERIC Educational Resources Information Center

    Barrett, David E.; Katsiyannis, Antonis; Zhang, Dalun; Zhang, Dake

    2014-01-01

    This study examined influences on delinquency and recidivism using structural equation modeling. The sample comprised 199,204 individuals: 99,602 youth whose cases had been processed by the South Carolina Department of Juvenile Justice and a matched control group of 99,602 youth without juvenile records. Structural equation modeling for the…

  3. Juvenile Hormone Regulation of Drosophila Epac - A Guanine Nucleotide Exchange Factor for Rap1 Small GTPase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously, we utilized a microchip array encompassing probes for 14,010 genes of Drosophila melanogaster to analyze the effect of (10R) juvenile hormone III (JH) on genome-wide gene expression in Drosophila S2 cells. Treatment with JH yielded a collection of 32 gene transcripts that demonstrated a ...

  4. Production of male neonates in four cladoceran species exposed to a juvenile hormone analog, fenoxycarb.

    PubMed

    Oda, Shigeto; Tatarazako, Norihisa; Watanabe, Hajime; Morita, Masatoshi; Iguchi, Taisen

    2005-06-01

    Previous studies have found that exposure of a cyclic parthenogen, the water flea Daphnia magna (Cladocera, Crustacea), to juvenile hormones and their analogs results in the production of neonates of male sex at concentration-dependent rates. We conducted reproduction experiments in four different species (Moina macrocopa, M. micrura, Ceriodaphnia dubia and C. reticulata) of cladoceran to test for the first time whether the occurrence of this phenomenon after exposure of the parent to such hormones is a generalized phenomenon. In the presence of a juvenile hormone analog, fenoxycarb, all four species produced male neonates and showed reduced rates of reproduction. The estimated median effective concentration (EC50) for the production of male neonates varied with species, ranging from 0.60 x 10(3) to 9.3 x 10(3) ng/l. Although there was a wide range of sensitivity to fenoxycarb, the production of male neonates in all four species demonstrates that this phenomenon is a common response to juvenile hormone analogs and further suggests that these hormones are capable of initiating sexual reproduction in cladocerans, most of which exhibit cyclic parthenogenesis.

  5. Juvenile Hormone Synthesis: “esterify then epoxidize” or “epoxidize then esterify”? Insights from the Structural Characterization of Juvenile Hormone Acid Methyltransferase

    PubMed Central

    Defelipe, L.A; Dolghih, E.; Roitberg, A.E.; Nouzova, M.; Mayoral, J.G; Noriega, F.G.; Turjanski, A.G.

    2011-01-01

    Juvenile hormones (JHs) play key roles in regulating metamorphosis and reproduction in insects. The last two steps of JH synthesis diverge depending on the insect order. In Lepidoptera, epoxidation by a P450 monooxygenase precedes esterification by a juvenile hormone acid methyltransferase (JHAMT). In Orthoptera, Dictyoptera, Coleoptera and Diptera epoxidation follows methylation. The aim of our study was to gain insight into the structural basis of JHAMT’s substrate recognition as a means to understand the divergence of these pathways. Homology modeling was used to build the structure of Aedes aegypti JHAMT. The substrate binding site was identified, as well as the residues that interact with the methyl donor (S-adenosylmethionine) and the carboxylic acid of the substrate methyl acceptors, farnesoic acid (FA) and juvenile hormone acid (JHA). To gain further insight we generated the structures of Anopheles gambiae, Bombyx mori, Drosophila melanogaster and Tribolium castaneum JHAMTs. The modeling results were compared with previous experimental studies using recombinant proteins, whole insects, corpora allata or tissue extracts. The computational study helps explain the selectivity towards the (10R)-JHA isomer and the reduced activity for palmitic and lauric acids. The analysis of our results supports the hypothesis that all insect JHAMTs are able to recognize both FA and JHA as substrates. Therefore, the order of the methylation/epoxidation reactions may be primarily imposed by the epoxidase’s substrate specificity. In Lepidoptera, epoxidase might have higher affinity than JHAMT for FA, so epoxidation precedes methylation, while in most other insects there is no epoxidation of FA, but esterification of FA to form MF, followed by epoxidation to JH III. PMID:21195763

  6. Influence of Photoperiod and Temperature on Migrations of Meloidogyne Juveniles

    PubMed Central

    Prot, Jean-Claude; Van Gundy, S. D.

    1981-01-01

    Photoperiod influences the migration of M. incognita juveniles toward tomato roots. Approximately 33% migrated vertically 20 cm in 7 days to roots when 12 h dark were alternated with 12 h light. Only 7% migrated when light was constant for 24 h. Vertical migration of M. incognita juveniles was studied at 14, 16, 18, 20, and 22 C. The migration of M. incognita juveniles begins at about 18 C and reaches its maximum at 22 C. The migration of M. hapla and M. incognita juveniles were compared at 14, 18, and 22 C. Juveniles of M. hapla were able to migrate at a lower temperature than those of M. incognita. With M. hapla, there was no significant difference in migration between 18 and 22 C. PMID:19300748

  7. Wolbachia-induced paternal defect in Drosophila is likely by interaction with the juvenile hormone pathway.

    PubMed

    Liu, Chen; Wang, Jia-Lin; Zheng, Ya; Xiong, En-Juan; Li, Jing-Jing; Yuan, Lin-Ling; Yu, Xiao-Qiang; Wang, Yu-Feng

    2014-06-01

    Wolbachia are endosymbionts that infect many insect species. They can manipulate the host's reproduction to increase their own maternal transmission. Cytoplasmic incompatibility (CI) is one such manipulation, which is expressed as embryonic lethality when Wolbachia-infected males mate with uninfected females. However, matings between males and females carrying the same Wolbachia strain result in viable progeny. The molecular mechanisms of CI are currently not clear. We have previously reported that the gene Juvenile hormone-inducible protein 26 (JhI-26) exhibited the highest upregulation in the 3rd instar larval testes of Drosophila melanogaster when infected by Wolbachia. This is reminiscent of an interaction between Wolbachia and juvenile hormone (JH) pathway in flies. Considering that Jhamt gene encodes JH acid methyltransferase, a key regulatory enzyme of JH biosynthesis, and that methoprene-tolerant (Met) has been regarded as the best JH receptor candidate, we first compared the expression of Jhamt and Met between Wolbachia-infected and uninfected fly testes to investigate whether Wolbachia infection influence the JH signaling pathway. We found that the expressions of Jhamt and Met were significantly increased in the presence of Wolbachia, suggesting an interaction of Wolbachia with the JH signaling pathway. Then, we found that overexpression of JhI-26 in Wolbachia-free transgenic male flies caused paternal-effect lethality that mimics the defects associated with CI. JhI-26 overexpressing males resulted in significantly decrease in hatch rate. Surprisingly, Wolbachia-infected females could rescue the egg hatch. In addition, we showed that overexpression of JhI-26 caused upregulation of the male accessory gland protein (Acp) gene CG10433, but not vice versa. This result suggests that JhI-26 may function at the upstream of CG10433. Likewise, overexpression of CG10433 also resulted in paternal-effect lethality. Both JhI-26 and CG10433 overexpressing males

  8. Juvenile hormone catabolism and oviposition in the codling moth, Cydia pomonella, as functions of age, mating status, and hormone treatment.

    PubMed

    Cole, Tracey J; Ramaswamy, Sonny B; Srinivasan, Asoka; Dorn, Silvia

    2002-01-01

    In vitro catabolism of juvenile hormone (JH) in haemolymph of adult female Cydia pomonella was ascribed mainly to juvenile hormone esterase (JHE) activity. No significant differences were noted between virgin and mated females 0-96 h post-emergence. Changes in JHE activity did not appear dependent upon fluctuations in JH titre; conversely, changes in JHE activity could not explain the changes in JH titres. Maximal JHE activity was recorded at 24 h (331.47 +/- 47.25 pmol/h/microl; 355.93 +/- 36.68 pmol/h/microl, virgin; mated insects, respectively) and preceded the peak in JH titres at 48 h. Topical application of JH II (10 ng-10 microg) or fenoxycarb (50 ng) enhanced JHE activity up to 640 and 56%, respectively. Treatment upon emergence with 10 microg JH II induced enzymic activity for less than 24 h, and when 10 microg JH II or 50 ng fenoxycarb were applied, circulating JH titres returned to control levels within 24 h. Oviposition was highly sensitive to exogenous JH and declined significantly with dosages >100 pg. To allow a degree of oocyte maturation before JH treatment, the hormone was administered at 6, 12, 24, or 48 h post-emergence and/or females were mated. Neither measure "protected" the system; oviposition declined immediately after JH application.

  9. Characterization of the juvenile hormone pathway in the viviparous cockroach, Diploptera punctata.

    PubMed

    Huang, Juan; Marchal, Elisabeth; Hult, Ekaterina F; Tobe, Stephen S

    2015-01-01

    Juvenile hormones (JHs) are key regulators of insect development and reproduction. The JH biosynthetic pathway is known to involve 13 discrete enzymatic steps. In the present study, we have characterized the JH biosynthetic pathway in the cockroach Diploptera punctata. The effect of exogenous JH precursors on JH biosynthesis was also determined. Based on sequence similarity, orthologs for the genes directly involved in the pathway were cloned, and their spatial and temporal transcript profiles were determined. The effect of shutting down the JH pathway in adult female cockroaches was studied by knocking down genes encoding HMG-CoA reductase (HMGR) and Juvenile hormone acid methyltransferase (JHAMT). As a result, oocyte development slowed as a consequence of reduction in JH biosynthesis. Oocyte length, fat body transcription of Vg and ovarian vitellin content significantly decreased. In addition, silencing HMGR and JHAMT resulted in a decrease in the transcript levels of other genes in the pathway.

  10. Characterization and affinity purification of juvenile hormone esterase from Bombyx mori.

    PubMed

    Shiotsuki, T; Bonning, B C; Hirai, M; Kikuchi, K; Hammock, B D

    2000-08-01

    Juvenile hormone esterase (JHE) from hemolymph of the silkworm moth Bombyx mori was characterized for substrate specificity and inhibitor sensitivity. B. mori JHE hydrolyzed the juvenile hormone surrogate substrate methyl n-heptylthioacetothioate (HEPTAT) more efficiently than p-nitrophenyl acetate and 1-naphthyl acetate substrates widely used to assay total carboxylesterase activity. B. mori JHE was sensitive to 3-octylthio-1,1,1-trifluoro-2-propanone (OTFP), which was developed as a selective inhibitor for lepidopteran JHE, and relatively insensitive to diisopropyl fluorophosphate (DFP), an inhibitor of serine esterases but not of all JHEs. Affinity purification with a trifluoromethyl ketone ligand was more efficient for purification of B. mori JHE than DEAE ion exchange chromatography.

  11. Cyp15F1: A novel cytochrome P450 gene linked to juvenile hormone-dependent caste differention in the termite R. flavipes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Termites are eusocial insects that perform social interactions that facilitate chemical signaling. Previous research identified two cytochrome P450s that have homology to other insect p450s responsible for the production of juvenile hormone. Juvenile hormone is an important morphogenic hormone tha...

  12. Resistance to juvenile hormone and an insect growth regulator in Drosophila is associated with an altered cytosolic juvenile hormone-binding protein

    SciTech Connect

    Shemshedini, L.; Wilson, T.G. )

    1990-03-01

    The Met mutant of Drosophila melanogaster is highly resistant to juvenile hormone III (JH III) or its chemical analog, methoprene, an insect growth regulator. Five major mechanisms of insecticide resistance were examined in Met and susceptible Met{sup +} flies. These two strains showed only minor differences when penetration, excretion, tissue sequestration, or metabolism of ({sup 3}H)JH III was measured. In contrast, when we examined JH III binding by a cytosolic binding protein from a JH target tissue, Met strains had a 10-fold lower binding affinity than did Met{sup +} strains. Studies using deficiency-bearing chromosomes provide strong evidence that the Met locus controls the binding protein characteristics and may encode the protein. These studies indicate that resistance in Met flies results from reduced binding affinity of a cytosolic binding protein for JH III.

  13. Juvenile hormone-binding proteins of Melanoplus bivittatus identified by EFDA photoaffinity labeling

    SciTech Connect

    Winder, B.S.

    1988-01-01

    Proteins that bind juvenile hormone in the hemolymph and fat body of the grasshopper, Melanoplus bivittatus were identified by photoaffinity labeling with radiolabeled epoxyfarnesyl diazoacetate ({sup 3}H-EFDA), and were characterized by electrophoretic analysis. A protocol was developed which allowed detection of {sup 3}H-EFDA that was covalently linked to proteins upon exposure to ultraviolet light at 254 nm. Quantification of protein-linked {sup 3}H-EFDA by liquid scintillation spectrometry took advantage of the differential solubility of unlinked {sup 3}H-EFDA in toluene alone, and of the protein-linked {sup 3}H-EFDA in toluene plus the detergent, Triton X-100. Competition between EFDA and juvenile hormone (JH) for binding to JH-specific binding sites was measured by hydroxyapatite protein binding assays in the presence of radiolabeled JH or EFDA and competing non-radiolabeled hormone. The protein-linked EFDA was detected on fluorograms of SDS or nondenaturing polyacrylamide gels (PAGE), and by liquid scintillation spectrometry of membranes to which the proteins had been electrophoretically transferred. Proteins which specifically bound JH were identified by photolabeling proteins in the presence and absence of nonlabeled JH-III.

  14. Insecticidal juvenile hormone analogs stimulate the production of male offspring in the crustacean Daphnia magna.

    PubMed

    Olmstead, Allen W; LeBlanc, Gerald A

    2003-06-01

    Juvenile hormone analogs (JHAs) represent a class of insecticides that were designed specifically to disrupt endocrine-regulated processes relatively unique to insects. Recently we demonstrated that the crustacean juvenoid hormone methyl farnesoate programs oocytes of the crustacean Daphnia magna to develop into males. We hypothesized that insecticidal JHAs might mimic the action of methyl farnesoate, producing altered sex ratios of offspring. Daphnids were exposed chronically (3 weeks) to sublethal concentrations of methyl farnesoate, the JHA pyriproxyfen, and several nonjuvenoid chemicals to discern whether excess male offspring production is a generic response to stress or a specific response to juvenoid hormones. Only methyl farnesoate and pyriproxyfen increased the percentage of males produced by exposed maternal organisms. As previously reported with methyl farnesoate, acute exposure (24 hr) to either pyriproxyfen or the JHA methoprene caused oocytes maturing in the ovary to develop into males. We performed experiments to determine whether combined effects of a JHA and methyl farnesoate conformed better to a model of concentration addition (indicative of same mechanism of action) or independent joint action (indicative of different mechanisms of action). Combined effects conformed better to the concentration-addition model, although some synergy, of unknown etiology, was evident between the insecticides and the hormone. These experiments demonstrate that insecticidal JHAs mimic the action of the crustacean juvenoid hormone methyl farnesoate, resulting in the inappropriate production of male offspring. The occurrence of such an effect in the environment could have dire consequences on susceptible crustacean populations.

  15. Evidence for differential biosynthesis of juvenile hormone (and related) sesquiterpenoids in Drosophila melanogaster.

    PubMed

    Bendena, William G; Zhang, Jinrui; Burtenshaw, Sally M; Tobe, Stephen S

    2011-05-15

    Previous studies in Drosophila melanogaster have demonstrated that biosynthesis and regulation of juvenile hormone bisepoxide (JHB(3)) may not be coordinated with that of juvenile hormone (JH III). In this study, we have used the radiochemical assay to confirm the coordinated developmental sesquiterpenoid profile during adult life and analyze the effect of farnesol and farnesoic acid addition on methyl farnesoate, JH III and JHB(3) production by isolated ring glands of Drosophila third instar larvae or corpora allata of adult females. Application of exogenous farnesol or farnesoic acid to glands in vitro stimulated MF and JH III biosynthesis in both larvae and adults. Farnesol and farnesoic acid were inhibitory to JHB(3) biosynthesis in larvae. N-acetyl-geranyl-L-cysteine (NAGC) and S-farnesyl-thioacetic acid (SFTA) are farnesyl pyrophosphatase inhibitors that have specificity towards two different ring gland phosphatases. NAGC and SFTA had no effect on MF or JH III biosynthesis, whereas SFTA inhibited JHB(3) biosynthesis. SFTA shows specificity for a ring gland phosphatase, Phos2680, which has not been previously implicated as a contributor to JHB(3) biosynthesis. This finding suggests that farnesol production occurs in two alternate pools; one pool utilized for MF and JH III production and the other for JHB(3) production. Finally, we have used the UAS-GAL4 system in Drosophila to express juvenile hormone acid methyltransferase (JHAMT) in vivo. In contrast to in vitro studies, JHAMT expression had no effect on MF or JH III biosynthesis but stimulated JHB(3) in both larvae and adults.

  16. The POU factor ventral veins lacking/Drifter directs the timing of metamorphosis through ecdysteroid and juvenile hormone signaling.

    PubMed

    Cheng, CeCe; Ko, Amy; Chaieb, Leila; Koyama, Takashi; Sarwar, Prioty; Mirth, Christen K; Smith, Wendy A; Suzuki, Yuichiro

    2014-06-01

    Although endocrine changes are known to modulate the timing of major developmental transitions, the genetic mechanisms underlying these changes remain poorly understood. In insects, two developmental hormones, juvenile hormone (JH) and ecdysteroids, are coordinated with each other to induce developmental changes associated with metamorphosis. However, the regulation underlying the coordination of JH and ecdysteroid synthesis remains elusive. Here, we examined the function of a homolog of the vertebrate POU domain protein, Ventral veins lacking (Vvl)/Drifter, in regulating both of these hormonal pathways in the red flour beetle, Tribolium castaneum (Tenebrionidae). RNA interference-mediated silencing of vvl expression led to both precocious metamorphosis and inhibition of molting in the larva. Ectopic application of a JH analog on vvl knockdown larvae delayed the onset of metamorphosis and led to a prolonged larval stage, indicating that Vvl acts upstream of JH signaling. Accordingly, vvl knockdown also reduced the expression of a JH biosynthesis gene, JH acid methyltransferase 3 (jhamt3). In addition, ecdysone titer and the expression of the ecdysone response gene, hormone receptor 3 (HR3), were reduced in vvl knockdown larvae. The expression of the ecdysone biosynthesis gene phantom (phm) and spook (spo) were reduced in vvl knockdown larvae in the anterior and posterior halves, respectively, indicating that Vvl might influence ecdysone biosynthesis in both the prothoracic gland and additional endocrine sources. Injection of 20-hydroxyecdysone (20E) into vvl knockdown larvae could restore the expression of HR3 although molting was never restored. These findings suggest that Vvl coordinates both JH and ecdysteroid biosynthesis as well as molting behavior to influence molting and the timing of metamorphosis. Thus, in both vertebrates and insects, POU factors modulate the production of major neuroendocrine regulators during sexual maturation.

  17. The POU Factor Ventral Veins Lacking/Drifter Directs the Timing of Metamorphosis through Ecdysteroid and Juvenile Hormone Signaling

    PubMed Central

    Chaieb, Leila; Koyama, Takashi; Sarwar, Prioty; Mirth, Christen K.; Smith, Wendy A.; Suzuki, Yuichiro

    2014-01-01

    Although endocrine changes are known to modulate the timing of major developmental transitions, the genetic mechanisms underlying these changes remain poorly understood. In insects, two developmental hormones, juvenile hormone (JH) and ecdysteroids, are coordinated with each other to induce developmental changes associated with metamorphosis. However, the regulation underlying the coordination of JH and ecdysteroid synthesis remains elusive. Here, we examined the function of a homolog of the vertebrate POU domain protein, Ventral veins lacking (Vvl)/Drifter, in regulating both of these hormonal pathways in the red flour beetle, Tribolium castaneum (Tenebrionidae). RNA interference-mediated silencing of vvl expression led to both precocious metamorphosis and inhibition of molting in the larva. Ectopic application of a JH analog on vvl knockdown larvae delayed the onset of metamorphosis and led to a prolonged larval stage, indicating that Vvl acts upstream of JH signaling. Accordingly, vvl knockdown also reduced the expression of a JH biosynthesis gene, JH acid methyltransferase 3 (jhamt3). In addition, ecdysone titer and the expression of the ecdysone response gene, hormone receptor 3 (HR3), were reduced in vvl knockdown larvae. The expression of the ecdysone biosynthesis gene phantom (phm) and spook (spo) were reduced in vvl knockdown larvae in the anterior and posterior halves, respectively, indicating that Vvl might influence ecdysone biosynthesis in both the prothoracic gland and additional endocrine sources. Injection of 20-hydroxyecdysone (20E) into vvl knockdown larvae could restore the expression of HR3 although molting was never restored. These findings suggest that Vvl coordinates both JH and ecdysteroid biosynthesis as well as molting behavior to influence molting and the timing of metamorphosis. Thus, in both vertebrates and insects, POU factors modulate the production of major neuroendocrine regulators during sexual maturation. PMID:24945490

  18. Interplay between insulin signaling, juvenile hormone, and vitellogenin regulates maternal effects on polyphenism in ants

    PubMed Central

    Libbrecht, Romain; Corona, Miguel; Wende, Franziska; Azevedo, Dihego O.; Serrão, Jose E.; Keller, Laurent

    2013-01-01

    Polyphenism is the phenomenon in which alternative phenotypes are produced by a single genotype in response to environmental cues. An extreme case is found in social insects, in which reproductive queens and sterile workers that greatly differ in morphology and behavior can arise from a single genotype. Experimental evidence for maternal effects on caste determination, the differential larval development toward the queen or worker caste, was recently documented in Pogonomyrmex seed harvester ants, in which only colonies with a hibernated queen produce new queens. However, the proximate mechanisms behind these intergenerational effects have remained elusive. We used a combination of artificial hibernation, hormonal treatments, gene expression analyses, hormone measurements, and vitellogenin quantification to investigate how the combined effect of environmental cues and hormonal signaling affects the process of caste determination in Pogonomyrmex rugosus. The results show that the interplay between insulin signaling, juvenile hormone, and vitellogenin regulates maternal effects on the production of alternative phenotypes and set vitellogenin as a likely key player in the intergenerational transmission of information. This study reveals how hibernation triggers the production of new queens in Pogonomyrmex ant colonies. More generally, it provides important information on maternal effects by showing how environmental cues experienced by one generation can translate into phenotypic variation in the next generation. PMID:23754378

  19. Sex Determination in Bees. IV. Genetic Control of Juvenile Hormone Production in MELIPONA QUADRIFASCIATA (Apidae)

    PubMed Central

    Kerr, Warwick Estevam; Akahira, Yukio; Camargo, Conceição A.

    1975-01-01

    Cell number and volume of corpora allata was determined for 8 phases of development, the first prepupal stage to adults 30 days old, in the social Apidae Melipona quadrifasciata. In the second prepupal stage a strong correlation was found between cell number and body weight ( r=0.651**), and cell number and corpora allata volume in prepupal stage (r=0.535*), which indicates that juvenile hormone has a definite role in caste determination in Melipona. The distribution of the volume of corpus allatum suggest a 3:1 segregation between bees with high volume of corpora allata against low and medium volume. This implies that genes xa and xb code for an enzyme that directly participates in juvenile hormone production. It was also concluded that the number of cells in the second prepupal stage is more important than the weight of the prepupa for caste determination. A scheme summarizing the genic control of sex and caste determination in Melipona bees in the prepupal phase is given. PMID:1213273

  20. BLACK SPOT INFESTATION IN JUVENILE COHO SALMON AND THE INFLUENCE OF OREGON COASTAL STREAM SUMMER TEMPERATURES

    EPA Science Inventory

    Freshwater survival and growth of juvenile salmon are affected by many factors, including high summer temperatures and other stressors such as parasitism. Delayed or suppressed growth related to stress can influence subsequent survival of juvenile salmonids in freshwater and mar...

  1. 20-Hydroxyecdysone stimulation of juvenile hormone biosynthesis by the mosquito corpora allata.

    PubMed

    Areiza, Maria; Nouzova, Marcela; Rivera-Perez, Crisalejandra; Noriega, Fernando G

    2015-09-01

    Juvenile hormone III (JH) is synthesized by the corpora allata (CA) and plays a key role in mosquito development and reproduction. JH titer decreases in the last instar larvae allowing pupation and metamorphosis to progress. As the anti-metamorphic role of JH comes to an end, the CA of the late pupa (or pharate adult) becomes again "competent" to synthesize JH, which plays an essential role orchestrating reproductive maturation. 20-hydroxyecdysone (20E) prepares the pupae for ecdysis, and would be an ideal candidate to direct a developmental program in the CA of the pharate adult mosquito. In this study, we provide evidence that 20E acts as an age-linked hormonal signal, directing CA activation in the mosquito pupae. Stimulation of the inactive brain-corpora allata-corpora cardiaca complex (Br-CA-CC) of the early pupa (24 h before adult eclosion or -24 h) in vitro with 20E resulted in a remarkable increase in JH biosynthesis, as well as increase in the activity of juvenile hormone acid methyltransferase (JHAMT). Addition of methyl farnesoate but not farnesoic acid also stimulated JH synthesis by the Br-CA-CC of the -24 h pupae, proving that epoxidase activity is present, but not JHAMT activity. Separation of the CA-CC complex from the brain (denervation) in the -24 h pupae also activated JH synthesis. Our results suggest that an increase in 20E titer might override an inhibitory effect of the brain on JH synthesis, phenocopying denervation. All together these findings provide compelling evidence that 20E acts as a developmental signal that ensures proper reactivation of JH synthesis in the mosquito pupae.

  2. Nutrient limitation results in juvenile hormone-mediated resorption of previtellogenic ovarian follicles in mosquitoes.

    PubMed

    Clifton, Mark E; Noriega, Fernando G

    2011-09-01

    Juvenile hormone (JH) is a central hormonal regulator of previtellogenic development in female Aedes aegypti mosquitoes. JH levels are low at eclosion and increase during the first day after adult emergence. This initial rise in JH is essential for female reproductive maturation. After previtellogenic maturation is complete, the mosquito enters a 'state-of-arrest' during which JH synthesis continues at a slower pace and further ovary development is repressed until a blood meal is taken. By examining the relationships between juvenile hormone, follicular resorption and nutrition in A. aegypti, we were able to define a critical role of JH during the previtellogenic resting stage. The rate of follicular resorption in resting stage mosquitoes is dependent on nutritional quality. Feeding water alone caused the rate of follicular resorption to reach over 20% by day 7 after emergence. Conversely, feeding a 20% sucrose solution caused resorption to remain below 5% during the entire experimental period. Mosquitoes fed 3% sucrose show rates of resorption intermediate between water and 20% sucrose and only reached 10% by day 7 after emergence. Follicular resorption is related to JH levels. Ligated abdomens separated from a source of JH (the corpora allata) showed an increase in resorption comparable to similarly aged starved mosquitoes (16%). Resorption in ligated abdomens was reduced to 6% by application of methoprene. The application of methoprene was also sufficient to prevent resorption in intact mosquitoes starved for 48 h (14% starved vs. 4% starved with methoprene). Additionally, active caspases were localized to resorbing follicles indicating that an apoptotic cell-death mechanism is responsible for follicular resorption during the previtellogenic resting stage. Taken together, these results indicate that JH mediates reproductive trade-offs in resting stage mosquitoes in response to nutrition.

  3. Identification of two juvenile hormone inducible transcription factors from the silkworm, Bombyx mori.

    PubMed

    Matsumoto, Hitoshi; Ueno, Chihiro; Nakamura, Yuki; Kinjoh, Terunori; Ito, Yuka; Shimura, Sachiko; Noda, Hiroaki; Imanishi, Shigeo; Mita, Kazuei; Fujiwara, Haruhiko; Hiruma, Kiyoshi; Shinoda, Tetsuro; Kamimura, Manabu

    2015-09-01

    Juvenile hormone (JH) regulates many physiological processes in insects. However, the signal cascades in which JH is active have not yet been fully elucidated, particularly in comparison to another major hormone ecdysteroid. Here we identified two JH inducible transcription factors as candidate components of JH signaling pathways in the silkworm, Bombyx mori. DNA microarray analysis showed that expression of two transcription factor genes, E75 and Enhancer of split mβ (E(spl)mβ), was induced by juvenile hormone I (JH I) in NIAS-Bm-aff3 cells. Real time RT-PCR analysis confirmed that expression of four E75 isoforms (E75A, E75B, E75C and E75D) and E(spl)mβ was 3-8 times greater after JH I addition. Addition of the protein synthesis inhibitor cycloheximide did not suppress JH-induced expression of the genes, indicating that they were directly induced by JH. JH-induced expression of E75 and E(spl)mβ was also observed in four other B. mori cell lines and in larval hemocytes of final instar larvae. Notably, E75A expression was induced very strongly in larval hemocytes by topical application of the JH analog fenoxycarb; the level of induced expression was comparable to that produced by feeding larvae with 20-hydroxyecdysone. These results suggest that E75 and E(spl)mβ are general and direct target genes of JH and that the transcription factors encoded by these genes play important roles in JH signaling.

  4. The glutathione-related detoxication responses to juvenile and ecdysone hormones in Galleria mellonella.

    PubMed

    Tarhan, Leman; Kayalı, Hülya Ayar; Karacali, Sabire

    2013-08-01

    The effect of 20-hydroxyecdysone (20E) and juvenile hormone (JH) on the glutathione pathway of the greater wax moth Galleria mellonella (Lepidoptera: Pyralidae) was determined by investigating glutathione peroxidase (GSH-Px), glutathione S-transferases (GST), and glutathione reductase (GR) activities as well as reduced and oxidized glutathione (GSH and GSSG) content with respect to developmental stage. The continuous decreases of GSH-Px and GST activities dependent on the growth period of G. mellonella occurred in JH and 20E groups over and under their controls, respectively. While the GR activities of G. mellonella showed increases in young pupa (YP) for both control and in old larvae (OL) for the 20E groups after the minimum at these periods, they also increased after old pupa (OP) for the JH group with a maximum in OL period. Although GR activity levels in the JH group were significantly higher compared with controls and 20E groups up to OP period, the activity levels for the control and 20E groups were higher than those of the JH group at adult (AD) and old pupa (OP) periods, respectively. In spite of increases in the GR activity of 20E and control groups of G. mellonella, decreased GSH and increased GSSG levels were observed at aging period. GSH levels in the JH group reached a maximum at prepupa (PP) and then decreased with non-significant changes from OL to AD period. According to the results, GSH and GSSG levels, as well as GSH/GSSG ratios, were below and over control levels in 20E and JH groups, respectively, during all of the investigated developmental stages. On the contrary, the LPO levels were higher than the control for 20E and lower for the JH groups during the developmental period. These results show that while ecdysone hormone has a negative effect on the glutathione-related detoxication capacity of G. mellonella, the juvenile hormone has a positive effect on this process.

  5. Nutrient limitation results in juvenile hormone-mediated resorption of previtellogenic ovarian follicles in mosquitoes

    PubMed Central

    Clifton, Mark E.; Noriega, Fernando G.

    2011-01-01

    Juvenile hormone (JH) is a central hormonal regulator of previtellogenic development in female Aedes aegypti mosquitoes. JH levels are low at eclosion and increase during the first day after adult emergence. This initial rise in JH is essential for female reproductive maturation. After previtellogenic maturation is complete, the mosquito enters a ‘state-of-arrest’ during which JH synthesis continues at a slower pace and further ovary development is repressed until a blood meal is taken. By examining the relationships between juvenile hormone, follicular resorption and nutrition in A. aegypti, we were able to define a critical role of JH during the previtellogenic resting stage. The rate of follicular resorption in resting stage mosquitoes is dependent on nutritional quality. Feeding water alone caused the rate of follicular resorption to reach over 20% by day 7 after emergence. Conversely, feeding a 20% sucrose solution caused resorption to remain below 5% during the entire experimental period. Mosquitoes fed 3% sucrose show rates of resorption intermediate between water and 20% sucrose and only reached 10% by day 7 after emergence. Follicular resorption is related to JH levels. Ligated abdomens separated from a source of JH (the corpora allata) showed an increase in resorption comparable to similarly aged starved mosquitoes (16%). Resorption in ligated abdomens was reduced to 6% by application of methoprene. The application of methoprene was also sufficient to prevent resorption in intact mosquitoes starved for 48 hours (14% starved vs. 4% starved with methoprene). Additionally, active caspases were localized to resorbing follicles indicating that an apoptotic cell-death mechanism is responsible for follicular resorption during the previtellogenic resting stage. Taken together, these results indicate that JH mediates reproductive trade-offs in resting stage mosquitoes in response to nutrition. PMID:21708165

  6. Brain sex differences and hormone influences

    PubMed Central

    Tobet, Stuart; Knoll, J. Gabriel; Hartshorn, Cheryl; Aurand, Emily; Stratton, Matthew; Kumar, Pankaj; Searcy, Brian; McClellan, Kristy

    2009-01-01

    Sex differences in the nervous system come in many forms. Although a majority of sexually dimorphic characteristics in brain have been described in older animals, mechanisms that determine sexually differentiated brain characteristics often operate during critical perinatal periods. Both genetic and hormonal factors likely contribute to physiological mechanisms in development to generate the ontogeny of sexual dimorphisms in brain. Relevant mechanisms may include neurogenesis, cell migration, cell differentiation, cell death, axon guidance and synaptogenesis. On a molecular level, there are several ways to categorize factors that drive brain development. These range from the actions of transcription factors in cell nuclei that regulate the expression of genes that control cell development and differentiation, to effector molecules that directly contribute to signaling from one cell to another. In addition, several peptides or proteins in these and other categories might be referred to as “biomarkers” of sexual differentiation with undetermined functions in development or adulthood. While a majority of sex differences are revealed as a direct consequence of hormone actions, some may only be revealed following genetic or environmental disruption. Sex differences in cell positions in the developing hypothalamus, and steroid hormone influences on cell movements in vitro, suggest that cell migration may be one target for early molecular actions that impact brain development and sexual differentiation. PMID:19207813

  7. Juvenile hormone titer in capped worker brood of Apis mellifera and reproduction in the bee mite Varroa jacobsoni.

    PubMed

    Rosenkranz, P; Rachinsky, A; Strambi, A; Strambi, C; Röpstorf, P

    1990-05-01

    Juvenile hormone (JH) titers were recorded from fifth instar worker larvae of Apis mellifera carnica, Apis mellifera lamarckii, and Africanized honeybees kept under temperate and tropical climatic conditions. No differences in hormone titer according to honeybee race or climatic conditions were determined. However, the rate of reproduction of the ectoparasitic mite, Varroa jacobsoni, on larvae of the different honeybee races was highly variable. The possible role of honeybee JH in control of the parasite's reproduction is discussed.

  8. Steroid hormone inactivation is required during the juvenile-adult transition in Drosophila.

    PubMed

    Rewitz, Kim F; Yamanaka, Naoki; O'Connor, Michael B

    2010-12-14

    Steroid hormones are systemic signaling molecules that regulate juvenile-adult transitions in both insects and mammals. In insects, pulses of the steroid hormone 20-hydroxyecdysone (20E) are generated by increased biosynthesis followed by inactivation/clearance. Although mechanisms that control 20E synthesis have received considerable recent attention, the physiological significance of 20E inactivation remains largely unknown. We show that the cytochrome P450 Cyp18a1 lowers 20E titer during the Drosophila prepupal to pupal transition. Furthermore, this reduction of 20E levels is a prerequisite to induce βFTZ-F1, a key factor in the genetic hierarchy that controls early metamorphosis. Resupplying βFTZ-F1 rescues Cyp18a1-deficient prepupae. Because Cyp18a1 is 20E-inducible, it appears that the increased production of steroid is responsible for its eventual decline, thereby generating the regulatory pulse required for proper temporal progression of metamorphosis. The coupling of hormone clearance to βFTZ-F1 expression suggests a general mechanism by which transient signaling drives unidirectional progression through a multistep process.

  9. Ligand-binding properties of a juvenile hormone receptor, Methoprene-tolerant

    PubMed Central

    Charles, Jean-Philippe; Iwema, Thomas; Epa, V. Chandana; Takaki, Keiko; Rynes, Jan; Jindra, Marek

    2011-01-01

    Juvenile hormone (JH) is a sesquiterpenoid of vital importance for insect development, yet the molecular basis of JH signaling remains obscure, mainly because a bona fide JH receptor has not been identified. Mounting evidence points to the basic helix–loop–helix (bHLH)/Per-Arnt-Sim (PAS) domain protein Methoprene-tolerant (Met) as the best JH receptor candidate. However, details of how Met transduces the hormonal signal are missing. Here, we demonstrate that Met specifically binds JH III and its biologically active mimics, methoprene and pyriproxyfen, through its C-terminal PAS domain. Substitution of individual amino acids, predicted to form a ligand-binding pocket, with residues possessing bulkier side chains reduces JH III binding likely because of steric hindrance. Although a mutation that abolishes JH III binding does not affect a Met–Met complex that forms in the absence of methoprene, it prevents both the ligand-dependent dissociation of the Met–Met dimer and the ligand-dependent interaction of Met with its partner bHLH-PAS protein Taiman. These results show that Met can sense the JH signal through direct, specific binding, thus establishing a unique class of intracellular hormone receptors. PMID:22167806

  10. Ligand-binding properties of a juvenile hormone receptor, Methoprene-tolerant.

    PubMed

    Charles, Jean-Philippe; Iwema, Thomas; Epa, V Chandana; Takaki, Keiko; Rynes, Jan; Jindra, Marek

    2011-12-27

    Juvenile hormone (JH) is a sesquiterpenoid of vital importance for insect development, yet the molecular basis of JH signaling remains obscure, mainly because a bona fide JH receptor has not been identified. Mounting evidence points to the basic helix-loop-helix (bHLH)/Per-Arnt-Sim (PAS) domain protein Methoprene-tolerant (Met) as the best JH receptor candidate. However, details of how Met transduces the hormonal signal are missing. Here, we demonstrate that Met specifically binds JH III and its biologically active mimics, methoprene and pyriproxyfen, through its C-terminal PAS domain. Substitution of individual amino acids, predicted to form a ligand-binding pocket, with residues possessing bulkier side chains reduces JH III binding likely because of steric hindrance. Although a mutation that abolishes JH III binding does not affect a Met-Met complex that forms in the absence of methoprene, it prevents both the ligand-dependent dissociation of the Met-Met dimer and the ligand-dependent interaction of Met with its partner bHLH-PAS protein Taiman. These results show that Met can sense the JH signal through direct, specific binding, thus establishing a unique class of intracellular hormone receptors.

  11. Juvenile hormone receptors in insect larval epidermis: identification by photoaffinity labeling.

    PubMed Central

    Palli, S R; Osir, E O; Eng, W; Boehm, M F; Edwards, M; Kulcsar, P; Ujvary, I; Hiruma, K; Prestwich, G D; Riddiford, L M

    1990-01-01

    Tritiated photoaffinity analogs of the natural lepidopteran juvenile hormones, JH I and II [epoxy[3H]bishomofarnesyl diazoacetate ([3H]EBDA) and epoxy[3H]homofarnesyl diazoacetate ([3H]EHDA)], and of the JH analog methoprene [[3H]methoprene diazoketone ([3H]MDK)] were synthesized and used to identify specific JH binding proteins in the larval epidermis of the tobacco hornworm (Manduca sexta). EBDA and EHDA specifically photolabeled a 29-kDa nuclear protein (pI 5.8). This protein and a second 29-kDa protein (pI 6.0) were labeled by MDK, but excess unlabeled methoprene or MDK only prevented binding to the latter. These 29-kDa proteins are also present in larval fat body but not in epidermis from either wandering stage or allatectomized larvae, which lack high-affinity JH binding sites. A 29-kDa nuclear protein with the same developmental specificity as this JH binder bound the DNA of two larval endocuticle genes. A 38-kDa cytosolic protein was also specifically photolabeled by these photoaffinity analogs. The 29-kDa nuclear protein is likely the high-affinity receptor for JH that mediates its genomic action, whereas the 38-kDa cytosolic protein may serve as an intracellular carrier for these highly lipophilic hormones and hormone analogs. Images PMID:11607060

  12. Control of larval and egg development in Aedes aegypti with Ribonucleic acid interference (RNAi) against juvenile hormone acid methyl transferase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ribonucleic acid interference (RNAi) is a powerful approach for elucidating gene functions in a variety of organisms, including mosquitoes and many other insects. Little has been done, however, to harness this approach in order to control adult and larval mosquitoes. Juvenile hormone (JH) plays a pi...

  13. Precocious sexual signalling and mating in Anastrepha fraterculus (Diptera: Tephritidae) sterile males achieved through juvenile hormone treatment and protein supplements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sexual maturation of Anastrepha fraterculus is a long process. Methoprene (a mimic of juvenile hormone) considerably reduces the time for sexual maturation in males. However, in other Anastrepha species, this effect depends on protein intake at the adult stage. Here, we evaluated the mating competit...

  14. Overexpression of Drosophila juvenile hormone esterase binding protein results in anti-JH effects and reduced pheromone abundance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The titer of juvenile hormone (JH), which has wide ranging physiological effects in insects, is regulated in part by JH esterase (JHE). We show that overexpression in Drosophila melanogaster of the JHE binding protein, DmP29 results in a series of apparent anti-JH effects. We hypothesize that DmP29 ...

  15. Gustatory perception and fat body energy metabolism are jointly affected by vitellogenin and juvenile hormone in honey bees.

    PubMed

    Wang, Ying; Brent, Colin S; Fennern, Erin; Amdam, Gro V

    2012-06-01

    Honey bees (Apis mellifera) provide a system for studying social and food-related behavior. A caste of workers performs age-related tasks: young bees (nurses) usually feed the brood and other adult bees inside the nest, while older bees (foragers) forage outside for pollen, a protein/lipid source, or nectar, a carbohydrate source. The workers' transition from nursing to foraging and their foraging preferences correlate with differences in gustatory perception, metabolic gene expression, and endocrine physiology including the endocrine factors vitellogenin (Vg) and juvenile hormone (JH). However, the understanding of connections among social behavior, energy metabolism, and endocrine factors is incomplete. We used RNA interference (RNAi) to perturb the gene network of Vg and JH to learn more about these connections through effects on gustation, gene transcripts, and physiology. The RNAi perturbation was achieved by single and double knockdown of the genes ultraspiracle (usp) and vg, which encode a putative JH receptor and Vg, respectively. The double knockdown enhanced gustatory perception and elevated hemolymph glucose, trehalose, and JH. We also observed transcriptional responses in insulin like peptide 1 (ilp1), the adipokinetic hormone receptor (AKHR), and cGMP-dependent protein kinase (PKG, or "foraging gene" Amfor). Our study demonstrates that the Vg-JH regulatory module controls changes in carbohydrate metabolism, but not lipid metabolism, when worker bees shift from nursing to foraging. The module is also placed upstream of ilp1, AKHR, and PKG for the first time. As insulin, adipokinetic hormone (AKH), and PKG pathways influence metabolism and gustation in many animals, we propose that honey bees have conserved pathways in carbohydrate metabolism and conserved connections between energy metabolism and gustatory perception. Thus, perhaps the bee can make general contributions to the understanding of food-related behavior and metabolic disorders.

  16. Characterization of an isopentenyl diphosphate isomerase involved in the juvenile hormone pathway in Aedes aegypti.

    PubMed

    Diaz, Miguel E; Mayoral, Jaime G; Priestap, Horacio; Nouzova, Marcela; Rivera-Perez, Crisalejandra; Noriega, Fernando G

    2012-10-01

    Isopentenyl diphosphate isomerase (IPPI) is an enzyme involved in the synthesis of juvenile hormone (JH) in the corpora allata (CA) of insects. IPPI catalyzes the conversion of isopentenyl pyrophosphate (IPP) to dimethylallyl pyrophosphate (DMAPP); afterward IPP and DMAPP condense in a head-to-tail manner to produce geranyl diphosphate (GPP), this head-to-tail condensation can be repeated, by the further reaction of GPP with IPP, yielding the JH precursor farnesyl diphosphate. An IPPI expressed sequence tag (EST) was obtained from an Aedes aegypti corpora-allata + corpora cardiaca library. Its full-length cDNA encodes a 244-aa protein that shows a high degree of similarity with type I IPPIs from other organisms, particularly for those residues that have important roles in catalysis, metal coordination and interaction with the diphosphate moiety of the IPP. Heterologous expression produced a recombinant protein that metabolized IPP into DMAPP; treatment of DMAPP with phosphoric acid produced isoprene, a volatile compound that was measured with an assay based on a solid-phase micro extraction protocol and direct analysis by gas chromatography. A. aegypti IPPI (AaIPPI) required Mg(2+) or Mn(2+) but not Zn(2+) for full activity and it was entirely inhibited by iodoacetamide. Real time PCR experiments showed that AaIPPI is highly expressed in the CA. Changes in AaIPPI mRNA levels in the CA in the pupal and adult female mosquito corresponded well with changes in JH synthesis (Li et al., 2003). This is the first molecular and functional characterization of an isopentenyl diphosphate isomerase involved in the production of juvenile hormone in the CA of an insect.

  17. Genetic differences in the production of male neonates in Daphnia magna exposed to juvenile hormone analogs.

    PubMed

    Oda, Shigeto; Tatarazako, Norihisa; Watanabe, Hajime; Morita, Masatoshi; Iguchi, Taisen

    2006-06-01

    We studied the susceptibility of three genetically different strains of the cyclical parthenogen Daphnia magna (Cladocera, Crustacea) in producing male neonates following exposure to juvenile hormone analogs. In experiment 1, NIES, Clone A, and Belgium A strains were exposed to the insect growth regulators (IGRs) fenoxycarb or epofenonane in a 21-day reproduction experiment. Fenoxycarb exposure decreased the total number of neonates and increased production of male neonates in a concentration-dependent manner in the NIES strain. The decrease in the total number of neonates was so great in Clone A following fenoxycarb exposure that male neonates were not observed, even at the highest concentration, where the total number of neonates was only 2% of the control. In the Belgium A strain, male neonates were observed at a rate of about 20% following exposure to the highest fenoxycarb concentration, but the total number observed was small. Epofenonane did not decrease reproduction in the NIES and Belgium A strains as dramatically as did fenoxycarb, but the neonatal sex ratio changed in a concentration-dependent manner. Although the ratio of males was as low as about 10%, induction of male neonates was also observed in Clone A following epofenonane exposure. In experiment 2, gravid females were exposed to high concentrations (5 or 10 microg/l) of fenoxycarb or pyriproxyfen for 12h. These treatments induced the production of male neonates in all strains, with a small decrease in the total number of neonates. Although induction of male neonates by juvenile hormones and their analogs was universal among genetically different strains, care is needed in interpreting the results of the 21-day reproduction tests, because decreased numbers of neonates at higher concentrations could obscure the presence of male neonates.

  18. Is Juvenile Hormone a potential mechanism that underlay the "branched Y-model"?

    PubMed

    Márquez-García, Armando; Canales-Lazcano, Jorge; Rantala, Markus J; Contreras-Garduño, Jorge

    2016-05-01

    Trade-offs are a central tenet in the life-history evolution and the simplest model to understand it is the "Y" model: the investment of one arm will affect the investment of the other arm. However, this model is by far more complex, and a "branched Y-model" is proposed: trade-offs could exist within each arm of the Y, but the mechanistic link is unknown. Here we used Tenebrio molitor to test if Juvenile Hormone (JH) could be a mechanistic link behind the "branched Y-model". Larvae were assigned to one of the following experimental groups: (1) low, (2) medium and (3) high doses of methoprene (a Juvenile Hormone analogue, JHa), (4) acetone (methoprene diluents; control one) or (5) näive (handled in the same way as other groups; control two). The JHa lengthened the time of development from larvae to pupae and larvae to adults, resulting in adults with a larger size. Males with medium and long JHa treatment doses were favored with female choice, but had smaller testes and fewer viable sperm. There were no differences between groups in regard to the number of spermatozoa of males, or the number of ovarioles or eggs of females. This results suggest that JH: (i) is a mechanistic link of insects "branched Y model", (ii) is a double ended-sword because it may not only provide benefits on reproduction but could also impose costs, and (iii) has a differential effect on each sex, being males more affected than females.

  19. Multiple exportins influence thyroid hormone receptor localization

    PubMed Central

    Subramanian, Kelly S.; Dziedzic, Rose C.; Nelson, Hallie N.; Stern, Mary E.; Roggero, Vincent R.; Bondzi, Cornelius; Allison, Lizabeth A.

    2015-01-01

    The thyroid hormone receptor (TR) undergoes nucleocytoplasmic shuttling and regulates target genes involved in metabolism and development. Previously, we showed that TR follows a CRM1/calreticulin-mediated nuclear export pathway. However, two lines of evidence suggest TR also follows another pathway: export is only partially blocked by leptomycin B (LMB), a CRM1-specific inhibitor; and we identified nuclear export signals in TR that are LMB-resistant. To determine whether other exportins are involved in TR shuttling, we used RNA interference and fluorescence recovery after photobleaching shuttling assays in transfected cells. Knockdown of exportins 4, 5, and 7 altered TR shuttling dynamics, and when exportins 5 and 7 were overexpressed, TR distribution shifted towards the cytosol. To further assess the effects of exportin overexpression, we examined transactivation of a TR-responsive reporter gene. Our data indicate that multiple exportins influence TR localization, highlighting a fine balance of nuclear import, retention, and export that modulates TR function. PMID:25911113

  20. Multiple exportins influence thyroid hormone receptor localization.

    PubMed

    Subramanian, Kelly S; Dziedzic, Rose C; Nelson, Hallie N; Stern, Mary E; Roggero, Vincent R; Bondzi, Cornelius; Allison, Lizabeth A

    2015-08-15

    The thyroid hormone receptor (TR) undergoes nucleocytoplasmic shuttling and regulates target genes involved in metabolism and development. Previously, we showed that TR follows a CRM1/calreticulin-mediated nuclear export pathway. However, two lines of evidence suggest TR also follows another pathway: export is only partially blocked by leptomycin B (LMB), a CRM1-specific inhibitor; and we identified nuclear export signals in TR that are LMB-resistant. To determine whether other exportins are involved in TR shuttling, we used RNA interference and fluorescence recovery after photobleaching shuttling assays in transfected cells. Knockdown of exportins 4, 5, and 7 altered TR shuttling dynamics, and when exportins 5 and 7 were overexpressed, TR distribution shifted toward the cytosol. To further assess the effects of exportin overexpression, we examined transactivation of a TR-responsive reporter gene. Our data indicate that multiple exportins influence TR localization, highlighting a fine balance of nuclear import, retention, and export that modulates TR function.

  1. Regulatory roles of biogenic amines and juvenile hormone in the reproductive behavior of the western tarnished plant bug (Lygus hesperus).

    PubMed

    Brent, Colin S; Miyasaki, Katelyn; Vuong, Connor; Miranda, Brittany; Steele, Bronwen; Brent, Kristoffer G; Nath, Rachna

    2016-02-01

    Mating induces behavioral and physiological changes in the plant bug Lygus hesperus Knight (Hemiptera: Miridae). After receiving seminal products, which include the systemic regulator juvenile hormone (JH), females enter a post-mating period lasting several days during which they enhance their oviposition rate and lose interest in remating. To elucidate the regulation of these behavioral changes in L. hesperus, biogenic amines were quantified in the heads of females at 5 min, 1 h and 24 h after copulation and compared to levels in virgins using high-performance liquid chromatography coupled with electrochemical detection. Mating significantly increased dopamine (DA) after 1 and 24 h, and decreased octopamine (OA) after 5 min and 1 h. Serotonin did not change with mating, but tyramine was significantly reduced after 5 min. While injection of amines into virgin females did not influence sexual receptivity, OA caused a decrease in oviposition during the 24 h following injection. Topical application of the JH analog methoprene to virgins caused an increase in DA, and a decline in mating propensity, but did not influence other amines or the oviposition rate. The results suggest the decline in OA observed immediately after mating may promote egg laying, and that male-derived JH may induce an increase in DA that could account for the post-mating loss of sexual receptivity.

  2. Juvenile hormone regulation of female reproduction in the common bed bug, Cimex lectularius

    PubMed Central

    Gujar, Hemant; Palli, Subba Reddy

    2016-01-01

    To begin studies on reproduction in common bed bug, Cimex lectularius, we identified three genes coding for vitellogenin (Vg, a protein required for the reproductive success of insects) and studied their hormonal regulation. RNA interference studied showed that expression of Vg3 gene in the adult females is a prerequisite for successful completion of embryogenesis in the eggs laid by them. Juvenile hormone (JH) receptor, Methoprene-tolerant (Met), steroid receptor coactivator (SRC) and GATAa but not ecdysone receptor (EcR) or its partner, ultraspiracle (USP) are required for expression of Vg genes. Feeding and mating working through Vg, Met, SRC, EcR, and GATAa regulate oocyte development. Knockdown of the expression of Met, SRC, EcR, USP, BR-C (Broad-Complex), TOR (target of rapamycin), and GATAa in female adults resulted in a reduction in the number eggs laid by them. Interestingly, Kruppel homolog 1 (Kr-h1) knockdown in the adult females did not reduce their fecundity but affected the development of embryos in the eggs laid by females injected with Kr-h1 double-stranded RNA. These data suggest that JH functioning through Met and SRC regulate both vitellogenesis and oogenesis in C. lectularius. However, JH does not work through Kr-h1 but may work through transcription factors not yet identified. PMID:27762340

  3. Evolution of Ecdysis and Metamorphosis in Arthropods: The Rise of Regulation of Juvenile Hormone.

    PubMed

    Cheong, Sam P S; Huang, Juan; Bendena, William G; Tobe, Stephen S; Hui, Jerome H L

    2015-11-01

    Arthropods are the most successful group of animals, and are found in diverse habitats; they account for more than 80% of described animal species. A rigid exoskeleton is a common feature that is shared across the different groups of arthropods. The exoskeleton offers protection and is shed between developmental stages via a unique evolutionarily conserved process known as molting/ecdysis. Molting is triggered by steroid hormones, the ecdysteroids, and the regulation of their biosynthesis has long been proposed as a contributor to the success of arthropods during evolution. Nevertheless, how novelties arose that contributed to the diversifications of arthropods remain unclear. Juvenile hormones (JHs) are sequiterpenoids that were thought to be unique to insects, modulating the timing of metamorphosis in conjunction with the actions of ecdysteroids. Here, we revisit the old question of "the role that the sesquiterpenoids play in arthropod evolution" with a focus on the neglected non-insect arthropods. We hypothesize that the sesquiterpenoid, methyl farnesoate (MF), had already established regulatory functions in the last common ancestor of arthropods, and the difference in the regulation of biosynthesis and degradation of sesquiterpenoids, such as MF and JH, was another major driving force in the successful radiation of insects.

  4. Argonaute 1 is indispensable for juvenile hormone mediated oogenesis in the migratory locust, Locusta migratoria.

    PubMed

    Song, Jiasheng; Guo, Wei; Jiang, Feng; Kang, Le; Zhou, Shutang

    2013-09-01

    Juvenile hormone (JH) is the primary hormone controlling vitellogenesis and oocyte maturation in the migratory locust Locusta migratoria, an evolutionarily primitive insect species with panoistic ovaries. However, molecular mechanisms of locust oogenesis remain unclear and the role of microRNA (miRNA) in JH mediated locust vitellogenesis and oocyte maturation has not been explored. Using miRNA sequencing and quantification with small RNA libraries derived from fat bodies of JH-deprived versus JH analog-exposed female adult locusts, we have identified 83 JH up-regulated and 60 JH down-regulated miRNAs. QRT-PCR validation has confirmed that transcription of selected miRNAs responded to JH administration and correlated with changes in endogenous hemolymph JH titers. Depletion of Argonaute 1 (Ago1), a key regulator of miRNA biogenesis and function by RNAi in female adult locusts dramatically decreased the expression of vitellogenin (Vg) and severely impaired follicular epithelium development, terminal oocyte maturation and ovarian growth. Our data indicate that Ago1 and Ago1-dependent miRNAs play a crucial role in locust vitellogenesis and egg production.

  5. Apis mellifera ultraspiracle: cDNA sequence and rapid up-regulation by juvenile hormone.

    PubMed

    Barchuk, A R; Maleszka, R; Simões, Z L P

    2004-10-01

    Two hormones, 20-hydroxyecdysone (20E) and juvenile hormone (JH) are key regulators of insect development including the differentiation of the alternative caste phenotypes of social insects. In addition, JH plays a different role in adult honey bees, acting as a 'behavioural pacemaker'. The functional receptor for 20E is a heterodimer consisting of the ecdysone receptor and ultraspiracle (USP) whereas the identity of the JH receptor remains unknown. We have cloned and sequenced a cDNA encoding Apis mellifera ultraspiracle (AMUSP) and examined its responses to JH. A rapid, but transient up-regulation of the AMUSP messenger is observed in the fat bodies of both queens and workers. AMusp appears to be a single copy gene that produces two transcripts ( approximately 4 and approximately 5 kb) that are differentially expressed in the animal's body. The predicted AMUSP protein shows greater sequence similarity to its orthologues from the vertebrate-crab-tick-locust group than to the dipteran-lepidopteran group. These characteristics and the rapid up-regulation by JH suggest that some of the USP functions in the honey bee may depend on ligand binding.

  6. Juvenile hormone regulation of female reproduction in the common bed bug, Cimex lectularius.

    PubMed

    Gujar, Hemant; Palli, Subba Reddy

    2016-10-20

    To begin studies on reproduction in common bed bug, Cimex lectularius, we identified three genes coding for vitellogenin (Vg, a protein required for the reproductive success of insects) and studied their hormonal regulation. RNA interference studied showed that expression of Vg3 gene in the adult females is a prerequisite for successful completion of embryogenesis in the eggs laid by them. Juvenile hormone (JH) receptor, Methoprene-tolerant (Met), steroid receptor coactivator (SRC) and GATAa but not ecdysone receptor (EcR) or its partner, ultraspiracle (USP) are required for expression of Vg genes. Feeding and mating working through Vg, Met, SRC, EcR, and GATAa regulate oocyte development. Knockdown of the expression of Met, SRC, EcR, USP, BR-C (Broad-Complex), TOR (target of rapamycin), and GATAa in female adults resulted in a reduction in the number eggs laid by them. Interestingly, Kruppel homolog 1 (Kr-h1) knockdown in the adult females did not reduce their fecundity but affected the development of embryos in the eggs laid by females injected with Kr-h1 double-stranded RNA. These data suggest that JH functioning through Met and SRC regulate both vitellogenesis and oogenesis in C. lectularius. However, JH does not work through Kr-h1 but may work through transcription factors not yet identified.

  7. Choristoneura fumiferana entomopoxvirus prevents metamorphosis and modulates juvenile hormone and ecdysteroid titers.

    PubMed

    Palli, S R; Ladd, T R; Tomkins, W L; Shu, S; Ramaswamy, S B; Tanaka, Y; Arif, B; Retnakaran, A

    2000-01-01

    Larvae of the spruce budworm, Choristoneura fumiferana, infected with C. fumiferana entomopoxvirus (CfEPV) continue to feed and grow without undergoing metamorphosis and die as moribund larvae. The lethal dose (LD(50)) and lethal time (LT(50)) values for fourth instar larvae are 2.4 spheroids and 25.2 days, respectively. One hundred percent of the control fourth instar larvae, which were fed water instead of virus, pupated by 18 days post feeding (PF). Only 30% of the larvae that were fed the LD(50) dose and none of the larvae that were fed the LD(95) dose pupated by 18 days PF. Of the control larvae, 95% became adults by 24 days PF, whereas in the treated group only 2% of larvae that were fed the LD(50) dose and none of the larvae that were fed the LD(95) dose became adults by 24 days PF. Some of the virus-treated larvae died as either larval/pupal or pupal/adult intermediates. These phenotypic effects were similar to the larval/pupal and pupal/adult intermediates, resulting from treating larvae with juvenile hormone (JH) or its analogs, which suggests that EPV may cause such abnormalities by modulating JH and/or ecdysteroid titers. In untreated sixth instar larvae the JH titer decreased to low levels by 24 h after ecdysis and remained low throughout larval life. EPV-fed sixth instar larvae had 2112 pg/ml on day 0, 477 pg/ml on day 1 and 875 pg/ml on day 8 of the sixth instar. Control larvae contained 860 ng of ecdysteroids per ml hemolymph on day 8 of the sixth instar, whereas EPV-treated larvae of the same age (30 days PF) had only 107 ng of ecdysteroids per ml of hemolymph. Thus, EPV infection results in increased JH titer and decreased ecdysteroid titer. Northern hybridization analysis was performed using RNA isolated from control and EPV-fed larvae and cDNA probes for (i) juvenile hormone esterase (JHE), which is JH inducible, (ii) Choristoneura hormone receptor 3 (CHR3), which is ecdysteroid inducible, and (iii) larval specific diapause associated protein 1

  8. National Implications in Juvenile Justice: The Influence of Juvenile Mentoring Programs on At Risk Youth.

    ERIC Educational Resources Information Center

    Belshaw, Scott H.; Kritsonis, William Allan

    2007-01-01

    In 1972 the federal government created the Juvenile Justice Delinquency Prevention Act that procured funding for various governmental programs to combat the sudden increase in juvenile crime. A provision of this Act set out the creation of mentoring programs to help decrease the juvenile crime rate and dropout rates in secondary schools. This…

  9. Molecular Determinants of Juvenile Hormone Action as Revealed by 3D QSAR Analysis in Drosophila

    PubMed Central

    Beňo, Milan; Farkaš, Robert

    2009-01-01

    Background Postembryonic development, including metamorphosis, of many animals is under control of hormones. In Drosophila and other insects these developmental transitions are regulated by the coordinate action of two principal hormones, the steroid ecdysone and the sesquiterpenoid juvenile hormone (JH). While the mode of ecdysone action is relatively well understood, the molecular mode of JH action remains elusive. Methodology/Principal Findings To gain more insights into the molecular mechanism of JH action, we have tested the biological activity of 86 structurally diverse JH agonists in Drosophila melanogaster. The results were evaluated using 3D QSAR analyses involving CoMFA and CoMSIA procedures. Using this approach we have generated both computer-aided and species-specific pharmacophore fingerprints of JH and its agonists, which revealed that the most active compounds must possess an electronegative atom (oxygen or nitrogen) at both ends of the molecule. When either of these electronegative atoms are replaced by carbon or the distance between them is shorter than 11.5 Å or longer than 13.5 Å, their biological activity is dramatically decreased. The presence of an electron-deficient moiety in the middle of the JH agonist is also essential for high activity. Conclusions/Significance The information from 3D QSAR provides guidelines and mechanistic scope for identification of steric and electrostatic properties as well as donor and acceptor hydrogen-bonding that are important features of the ligand-binding cavity of a JH target protein. In order to refine the pharmacophore analysis and evaluate the outcomes of the CoMFA and CoMSIA study we used pseudoreceptor modeling software PrGen to generate a putative binding site surrogate that is composed of eight amino acid residues corresponding to the defined molecular interactions. PMID:19547707

  10. Precocious metamorphosis in the juvenile hormone-deficient mutant of the silkworm, Bombyx mori.

    PubMed

    Daimon, Takaaki; Kozaki, Toshinori; Niwa, Ryusuke; Kobayashi, Isao; Furuta, Kenjiro; Namiki, Toshiki; Uchino, Keiro; Banno, Yutaka; Katsuma, Susumu; Tamura, Toshiki; Mita, Kazuei; Sezutsu, Hideki; Nakayama, Masayoshi; Itoyama, Kyo; Shimada, Toru; Shinoda, Tetsuro

    2012-01-01

    Insect molting and metamorphosis are intricately governed by two hormones, ecdysteroids and juvenile hormones (JHs). JHs prevent precocious metamorphosis and allow the larva to undergo multiple rounds of molting until it attains the proper size for metamorphosis. In the silkworm, Bombyx mori, several "moltinism" mutations have been identified that exhibit variations in the number of larval molts; however, none of them have been characterized molecularly. Here we report the identification and characterization of the gene responsible for the dimolting (mod) mutant that undergoes precocious metamorphosis with fewer larval-larval molts. We show that the mod mutation results in complete loss of JHs in the larval hemolymph and that the mutant phenotype can be rescued by topical application of a JH analog. We performed positional cloning of mod and found a null mutation in the cytochrome P450 gene CYP15C1 in the mod allele. We also demonstrated that CYP15C1 is specifically expressed in the corpus allatum, an endocrine organ that synthesizes and secretes JHs. Furthermore, a biochemical experiment showed that CYP15C1 epoxidizes farnesoic acid to JH acid in a highly stereospecific manner. Precocious metamorphosis of mod larvae was rescued when the wild-type allele of CYP15C1 was expressed in transgenic mod larvae using the GAL4/UAS system. Our data therefore reveal that CYP15C1 is the gene responsible for the mod mutation and is essential for JH biosynthesis. Remarkably, precocious larval-pupal transition in mod larvae does not occur in the first or second instar, suggesting that authentic epoxidized JHs are not essential in very young larvae of B. mori. Our identification of a JH-deficient mutant in this model insect will lead to a greater understanding of the molecular basis of the hormonal control of development and metamorphosis.

  11. Common and Distinct Roles of Juvenile Hormone Signaling Genes in Metamorphosis of Holometabolous and Hemimetabolous Insects

    PubMed Central

    Jindra, Marek

    2011-01-01

    Insect larvae metamorphose to winged and reproductive adults either directly (hemimetaboly) or through an intermediary pupal stage (holometaboly). In either case juvenile hormone (JH) prevents metamorphosis until a larva has attained an appropriate phase of development. In holometabolous insects, JH acts through its putative receptor Methoprene-tolerant (Met) to regulate Krüppel-homolog 1 (Kr-h1) and Broad-Complex (BR-C) genes. While Met and Kr-h1 prevent precocious metamorphosis in pre-final larval instars, BR-C specifies the pupal stage. How JH signaling operates in hemimetabolous insects is poorly understood. Here, we compare the function of Met, Kr-h1 and BR-C genes in the two types of insects. Using systemic RNAi in the hemimetabolous true bug, Pyrrhocoris apterus, we show that Met conveys the JH signal to prevent premature metamorphosis by maintaining high expression of Kr-h1. Knockdown of either Met or Kr-h1 (but not of BR-C) in penultimate-instar Pyrrhocoris larvae causes precocious development of adult color pattern, wings and genitalia. A natural fall of Kr-h1 expression in the last larval instar normally permits adult development, and treatment with an exogenous JH mimic methoprene at this time requires both Met and Kr-h1 to block the adult program and induce an extra larval instar. Met and Kr-h1 therefore serve as JH-dependent repressors of deleterious precocious metamorphic changes in both hemimetabolous and holometabolous juveniles, whereas BR-C has been recruited for a new role in specifying the holometabolous pupa. These results show that despite considerable evolutionary distance, insects with diverse developmental strategies employ a common-core JH signaling pathway to commit to adult morphogenesis. PMID:22174880

  12. Common and distinct roles of juvenile hormone signaling genes in metamorphosis of holometabolous and hemimetabolous insects.

    PubMed

    Konopova, Barbora; Smykal, Vlastimil; Jindra, Marek

    2011-01-01

    Insect larvae metamorphose to winged and reproductive adults either directly (hemimetaboly) or through an intermediary pupal stage (holometaboly). In either case juvenile hormone (JH) prevents metamorphosis until a larva has attained an appropriate phase of development. In holometabolous insects, JH acts through its putative receptor Methoprene-tolerant (Met) to regulate Krüppel-homolog 1 (Kr-h1) and Broad-Complex (BR-C) genes. While Met and Kr-h1 prevent precocious metamorphosis in pre-final larval instars, BR-C specifies the pupal stage. How JH signaling operates in hemimetabolous insects is poorly understood. Here, we compare the function of Met, Kr-h1 and BR-C genes in the two types of insects. Using systemic RNAi in the hemimetabolous true bug, Pyrrhocoris apterus, we show that Met conveys the JH signal to prevent premature metamorphosis by maintaining high expression of Kr-h1. Knockdown of either Met or Kr-h1 (but not of BR-C) in penultimate-instar Pyrrhocoris larvae causes precocious development of adult color pattern, wings and genitalia. A natural fall of Kr-h1 expression in the last larval instar normally permits adult development, and treatment with an exogenous JH mimic methoprene at this time requires both Met and Kr-h1 to block the adult program and induce an extra larval instar. Met and Kr-h1 therefore serve as JH-dependent repressors of deleterious precocious metamorphic changes in both hemimetabolous and holometabolous juveniles, whereas BR-C has been recruited for a new role in specifying the holometabolous pupa. These results show that despite considerable evolutionary distance, insects with diverse developmental strategies employ a common-core JH signaling pathway to commit to adult morphogenesis.

  13. Metabolic analysis reveals changes in the mevalonate and juvenile hormone synthesis pathways linked to the mosquito reproductive physiology.

    PubMed

    Rivera-Perez, Crisalejandra; Nouzova, Marcela; Lamboglia, Ivanna; Noriega, Fernando G

    2014-08-01

    Juvenile hormone (JH) regulates reproductive maturation in insects; therefore interruption of JH biosynthesis has been considered as a strategy for the development of target-specific insecticides. The corpora allata (CA) from mosquitoes is highly specialized to supply variable levels of JH, which are linked to ovarian developmental stages and influenced by nutritional signals. However, very little is known about how changes in JH synthesis relate to reproductive physiology and how JH synthesis regulation is translated into changes in the CA machinery. With the advent of new methods that facilitate the analysis of transcripts, enzymes and metabolites in the minuscule CA, we were able to provide comprehensive descriptions of the mevalonic (MVA) and JH synthesis pathways by integrating information on changes in the basic components of those pathways. Our results revealed remarkable dynamic changes in JH synthesis and exposed part of a complex mechanism that regulates CA activity. Principal component (PC) analyses validated that both pathways (MVAP and JH-branch) are transcriptionally co-regulated as a single unit, and catalytic activities for the enzymes of the MVAP and JH-branch also changed in a coordinate fashion. Metabolite studies showed that global fluctuations in the intermediate pool sizes in the MVAP and JH-branch were often inversely related. PC analyses suggest that in female mosquitoes, there are at least 4 developmental switches that alter JH synthesis by modulating the flux at distinctive points in both pathways.

  14. The roles of juvenile hormone, insulin/target of rapamycin, and ecydsone signaling in regulating body size in Drosophila

    PubMed Central

    Mirth, Christen Kerry; Shingleton, Alexander William

    2014-01-01

    Understanding how organisms regulate their body size has interested biologists for decades. Recent work has shown that both insulin/target of rapamycin (TOR) signaling and the steroid hormone ecdysone act to regulate rates of growth and the duration of the growth period in the fruit fly, Drosophila melanogaster. Our recent work has uncovered a third level of interaction, whereby juvenile hormone (JH) regulates levels of both ecdysone and insulin/TOR signaling to control growth rates. These studies highlight a complex network of interactions involved in regulating body and organ size. PMID:26842847

  15. E-cadherin roles in animal biology: A perspective on thyroid hormone-influence.

    PubMed

    Izaguirre, María Fernanda; Casco, Victor Hugo

    2016-11-04

    The establishment, remodeling and maintenance of tissular architecture during animal development, and even across juvenile to adult life, are deeply regulated by a delicate interplay of extracellular signals, cell membrane receptors and intracellular signal messengers. It is well known that cell adhesion molecules (cell-cell and cell-extracellular matrix) play a critical role in these processes. Particularly, adherens junctions (AJs) mediated by E-cadherin and catenins determine cell-cell contact survival and epithelia function. Consequently, this review seeks to encompass the complex and prolific knowledge about E-cadherin roles during physiological and pathological states, particularly focusing on the influence exerted by the thyroid hormone (TH).

  16. Sex-steroid and thyroid hormone concentrations in juvenile alligators (Alligator mississippiensis) from contaminated and reference lakes in Florida, USA

    USGS Publications Warehouse

    Grain, D.A.; Guillette, L.J.; Pickford, D.B.; Percival, H.F.; Woodward, A.R.

    1998-01-01

    Sex-steroid and thyroid hormones are critical regulators of growth and reproduction in all vertebrates, and several recent studies suggest that environmental chemicals can alter circulating concentrations of these hormones. This study examines plasma concentrations of estradiol-171?? (E2), testosterone (T), triiodothyronine (T3), and thyroxine (T4) in juvenile alligators (60-140 cm total length) from two contaminated lakes and one reference lake in Florida. First, the data were analyzed by comparing hormone concentrations among males and females from the different lakes. Whereas there were no differences in plasma E2 concentrations among animals of the three lakes, male alligators from the contaminated lakes (Lake Apopka and Lake Okeechobee) had significantly lower plasma T concentrations compared 10 males from the reference take (Lake Woodruff). Concentrations of thyroid hormones also differed in animals of the three lakes, with T4 concentrations being elevated in Lake Okeechobee males compared to Lake Woodruff males. Second, the relationship between body size and hormone concentration was examined using regression analysis. Most notably for steroid hormones, no clear relationship was detected between E2 and total length in Apopka females (r2 0.09, p = 0.54) or between T and total length in Apopka males (r2 = 0.007, p = 0.75). Females from Apopka (r2 = 0.318, p = 0.09) and Okeechobee (r2 = 0.222, p = 0.09) exhibited weak correlations between T3 and total length. Males from Apopka (r2 = 0.015, p = 0.66) and Okeechobee (r2 = 0.128, p = 0.19) showed no correlation between T4 and total length. These results indicate: some of the previously reported abnormalities in steroid hormones of hatchling alligators persist, at least, through the juvenile years; steroid and thyroid hormones are related to body size in juvenile alligators from the reference lake, whereas alligators living in lakes Apopka and Okeechobee experience alterations in circulating thyroid and steroid

  17. Roles of ecdysteroid and juvenile hormone in vitellogenesis in an endoparasitic wasp, Pteromalus puparum (Hymenoptera: Pteromalidae).

    PubMed

    Dong, Sheng-zhang; Ye, Gong-yin; Guo, Jian-yang; Hu, Cui

    2009-01-01

    To elucidate the endocrine regulation of vitellogenesis in an endoparastic wasp (Pteromalus puparum), the titers of ecdysteroid and juvenile hormone (JH) from the whole bodies are measured using the method of radioimmunoassay and GC-MS, and compared with the levels of vitellogenin (Vg) mRNA in the fat bodies, hemolymph Vg and ovarian vitellin (Vt), respectively. The results show that the ecdysteroid titer and fat body Vg mRNA level have a similar dynamics tendency, and the peak titer is at adult eclosion. The titer of JH III and ovarian Vt also have a similar dynamics tendency, and the peak titer is at 48h after eclosion. The profiles of hemolymph Vg, Vg mRNA in fat bodies and ovarian Vt, are also measured in the wasps after treated with different amounts of 20-hydroxyecdysone (20HE) or JH III in female pupa and adults. The results show that 20HE stimulates Vg synthesis in the fat bodies and its release into the hemolymph, and that JH III only accelerates Vg sequestration in the oocytes. Decapitation, which is believed to terminate synthesis of JH in insects, can not inhibit vitellogenesis and oocyte maturation in P. puparum. Furthermore, Vg gene is expressed with a lower titer of JH and depressed by a higher titer of JH III. These studies suggest that ecdysteroids play a role in Vg synthesis and believed to be the dominant hormones in regulation of vitellogenesis in P. puparum, and JHs are not the essential factors to female reproduction in this wasp.

  18. Hormone profile in juvenile systemic lupus erythematosus with previous or current amenorrhea.

    PubMed

    Silva, Clovis A; Deen, Maria E J; Febrônio, Marilia V; Oliveira, Sheila K; Terreri, Maria T; Sacchetti, Silvana B; Sztajnbok, Flavio R; Marini, Roberto; Quintero, Maria V; Bica, Blanca E; Pereira, Rosa M; Bonfá, Eloisa; Ferriani, Virginia P; Robazzi, Teresa C; Magalhães, Claudia S; Hilário, Maria O

    2011-08-01

    To identify the underlying mechanism of amenorrhea in juvenile systemic lupus erythematosus (JSLE) patients, thirty-five (11.7%) JSLE patients with current or previous amenorrhea were consecutively selected among the 298 post-menarche patients followed in 12 Brazilian pediatric rheumatology centers. Pituitary gonadotrophins [follicle-stimulating hormone (FSH) and luteinizing hormone (LH)] and estradiol were evaluated in 32/35 patients, and prolactin and total testosterone in 29/35 patients. Patient's medical records were carefully reviewed according to demographic, clinical and therapeutic findings. The mean duration of amenorrhea was 7.2 ± 3.6 months. Low FSH or LH was observed in 7/32 (22%) JSLE patients and normal FSH or LH in 25 (78%). Remarkably, low levels of FSH or LH were associated with higher frequency of current amenorrhea (57% vs. 0%, P = 0.001), higher median disease activity (SLEDAI) and damage (SLICC/ACR-DI) (18 vs. 4, P = 0.011; 2 vs. 0, P = 0.037, respectively) and higher median current dose of prednisone (60 vs. 10 mg/day, P = 0.0001) compared to normal FSH or LH JSLE patients. None of them had decreased ovarian reserve and premature ovarian failure. Six of 29 (21%) patients had high levels of prolactin, and none had current amenorrhea. No correlations were observed between levels of prolactin and SLEDAI, and levels of prolactin and SLICC/ACR-DI scores (Spearman's coefficient). We have identified that amenorrhea in JSLE is associated with high dose of corticosteroids indicated for active disease due to hypothalamic-pituitary-ovary axis suppression.

  19. Effects of juvenile hormone and ecdysone on the timing of vitellogenin appearance in hemolymph of queen and worker pupae of Apis mellifera

    PubMed Central

    Barchuk, Angel Roberto; Bitondi, Marcia Maria Gentile; Simões, Zilá Luz Paulino

    2002-01-01

    The caste-specific regulation of vitellogenin synthesis in the honeybee represents a problem with many yet unresolved details. We carried out experiments to determine when levels of vitellogenin are first detected in hemolymph of female castes of Apis mellifera, and whether juvenile hormone and ecdysteroids modulate this process. Vitellogenin levels were measured in hemolymph using immunological techniques. We show that in both castes the appearance of vitellogenin in the hemolymph occurs during the pupal period, but the timing was different in the queen and worker. Vitellogenin appears in queens during an early phase of cuticle pigmentation approximately 60h before eclosion, while in workers the appearance of vitellogenin is more delayed, initiating in the pharate adult stage, approximately 10h before eclosion. The timing of vitellogenin appearance in both castes coincides with a slight increase in endogenous levels of juvenile hormone that occurs at the end of pupal development. The correlation between these events was corroborated by topical application of juvenile hormone. Exogenous juvenile hormone advanced the timing of vitellogenin appearance in both castes, but caste-specific differences in timing were maintained. Injection of actinomycin D prevented the response to juvenile hormone. In contrast, queen and worker pupae that were treated with ecdysone showed a delay in the appearance of vitellogenin. These data suggest that queens and workers share a common control mechanism for the timing of vitellogenin synthesis, involving an increase in juvenile hormone titers in the presence of low levels of ecdysteroids. PMID:15455035

  20. Juvenile hormone biosynthesis in adult Blattella germanica requires nuclear receptors Seven-up and FTZ-F1

    PubMed Central

    Borras-Castells, Ferran; Nieva, Claudia; Maestro, José L.; Maestro, Oscar; Belles, Xavier; Martín, David

    2017-01-01

    In insects, the transition from juvenile development to the adult stage is controlled by juvenile hormone (JH) synthesized from the corpora allata (CA) glands. Whereas a JH-free period during the last juvenile instar triggers metamorphosis and the end of the growth period, the reappearance of this hormone after the imaginal molt marks the onset of reproductive adulthood. Despite the importance of such transition, the regulatory mechanism that controls it remains mostly unknown. Here, using the hemimetabolous insect Blattella germanica, we show that nuclear hormone receptors Seven-up-B (BgSvp-B) and Fushi tarazu-factor 1 (BgFTZ-F1) have essential roles in the tissue- and stage-specific activation of adult CA JH-biosynthetic activity. Both factors are highly expressed in adult CA cells. Moreover, RNAi-knockdown of either BgSvp-B or BgFTZ-F1 results in adult animals with a complete block in two critical JH-dependent reproductive processes, vitellogenesis and oogenesis. We show that this reproductive blockage is the result of a dramatic impairment of JH biosynthesis, due to the CA-specific reduction in the expression of two key JH biosynthetic enzymes, 3-hydroxy-3-methylglutaryl coenzyme A synthase-1 (BgHMG-S1) and HMG-reductase (BgHMG-R). Our findings provide insights into the regulatory mechanisms underlying the specific changes in the CA gland necessary for the proper transition to adulthood. PMID:28074850

  1. Juvenile hormone biosynthesis in adult Blattella germanica requires nuclear receptors Seven-up and FTZ-F1.

    PubMed

    Borras-Castells, Ferran; Nieva, Claudia; Maestro, José L; Maestro, Oscar; Belles, Xavier; Martín, David

    2017-01-11

    In insects, the transition from juvenile development to the adult stage is controlled by juvenile hormone (JH) synthesized from the corpora allata (CA) glands. Whereas a JH-free period during the last juvenile instar triggers metamorphosis and the end of the growth period, the reappearance of this hormone after the imaginal molt marks the onset of reproductive adulthood. Despite the importance of such transition, the regulatory mechanism that controls it remains mostly unknown. Here, using the hemimetabolous insect Blattella germanica, we show that nuclear hormone receptors Seven-up-B (BgSvp-B) and Fushi tarazu-factor 1 (BgFTZ-F1) have essential roles in the tissue- and stage-specific activation of adult CA JH-biosynthetic activity. Both factors are highly expressed in adult CA cells. Moreover, RNAi-knockdown of either BgSvp-B or BgFTZ-F1 results in adult animals with a complete block in two critical JH-dependent reproductive processes, vitellogenesis and oogenesis. We show that this reproductive blockage is the result of a dramatic impairment of JH biosynthesis, due to the CA-specific reduction in the expression of two key JH biosynthetic enzymes, 3-hydroxy-3-methylglutaryl coenzyme A synthase-1 (BgHMG-S1) and HMG-reductase (BgHMG-R). Our findings provide insights into the regulatory mechanisms underlying the specific changes in the CA gland necessary for the proper transition to adulthood.

  2. Identification of plant compounds that disrupt the insect juvenile hormone receptor complex.

    PubMed

    Lee, Seok-Hee; Oh, Hyun-Woo; Fang, Ying; An, Saes-Byeol; Park, Doo-Sang; Song, Hyuk-Hwan; Oh, Sei-Ryang; Kim, Soo-Young; Kim, Seonghyun; Kim, Namjung; Raikhel, Alexander S; Je, Yeon Ho; Shin, Sang Woon

    2015-02-10

    Insects impact human health through vector-borne diseases and cause major economic losses by damaging crops and stored agricultural products. Insect-specific growth regulators represent attractive control agents because of their safety to the environment and humans. We identified plant compounds that serve as juvenile hormone antagonists (PJHANs). Using the yeast two-hybrid system transformed with the mosquito JH receptor as a reporter system, we demonstrate that PJHANs affect the JH receptor, methoprene-tolerant (Met), by disrupting its complex with CYCLE or FISC, formation of which is required for mediating JH action. We isolated five diterpene secondary metabolites with JH antagonist activity from two plants: Lindera erythrocarpa and Solidago serotina. They are effective in causing mortality of mosquito larvae at relatively low LD50 values. Topical application of two diterpenes caused reduction in the expression of Met target genes and retardation of follicle development in mosquito ovaries. Hence, the newly discovered PJHANs may lead to development of a new class of safe and effective pesticides.

  3. Glutamate-gated chloride channels inhibit juvenile hormone biosynthesis in the cockroach, Diploptera punctata.

    PubMed

    Liu, Hsin-Ping; Lin, Shu-Chen; Lin, Chi-Yen; Yeh, Shih-Rung; Chiang, Ann-Shyn

    2005-11-01

    Juvenile hormone (JH) synthesized and released from endocrine gland corpus allatum (CA) plays an important role in insect metamorphosis, vitellogenesis and reproduction. Glutamate is a major neurotransmitter in the nervous system and its activated receptors possess excitatory and inhibitory forms in muscle fibers of invertebrates. Previously, we have shown that the rise of intracellular calcium through excitatory glutamate receptors, N-methyl-d-aspartate (NMDA) and non-NMDA-type channels stimulates JH synthesis in the cockroach, Diploptera punctata. Here, we demonstrate the occurrence of inhibitory chloride permeable glutamate (GluCl) receptors on CA cell membranes. Application of the GluCl channel activators, ibotenic acid (Ibo) and ivermectin, but not gamma-aminobutyric acid caused a decline in JH synthesis in glands of either high or low activity during the gonadotrophic cycle. Also, while recording the membrane potential of the isolated whole CA glands intracellularly, Ibo induced a hyperpolarizated response. Both changes in the membrane potential and inhibition of JH synthesis could be abolished by the application of the chloride channel blocker picrotoxin. Finally, we found both excitatory and inhibitory glutamate receptors cause antagonistic effects on rates of JH synthesis. These results indicate a novel function of GluCl channels in the inhibition of JH synthesis that could be a potential pathway for developing a new generation of insecticides.

  4. Homeodomain Protein Scr Regulates the Transcription of Genes Involved in Juvenile Hormone Biosynthesis in the Silkworm.

    PubMed

    Meng, Meng; Liu, Chun; Peng, Jian; Qian, Wenliang; Qian, Heying; Tian, Ling; Li, Jiarui; Dai, Dandan; Xu, Anying; Li, Sheng; Xia, Qingyou; Cheng, Daojun

    2015-11-02

    The silkworm Dominant trimolting (Moltinism, M³) mutant undergoes three larval molts and exhibits precocious metamorphosis. In this study, we found that compared with the wild-type (WT) that undergoes four larval molts, both the juvenile hormone (JH) concentration and the expression of the JH-responsive gene Krüppel homolog 1 (Kr-h1) began to be greater in the second instar of the M³ mutant. A positional cloning analysis revealed that only the homeodomain transcription factor gene Sex combs reduced (Scr) is located in the genomic region that is tightly linked to the M³ locus. The expression level of the Scr gene in the brain-corpora cardiaca-corpora allata (Br-CC-CA) complex, which controls the synthesis of JH, was very low in the final larval instar of both the M³ and WT larvae, and exhibited a positive correlation with JH titer changes. Importantly, luciferase reporter analysis and electrophoretic mobility shift assay (EMSA) demonstrated that the Scr protein could promote the transcription of genes involved in JH biosynthesis by directly binding to the cis-regulatory elements (CREs) of homeodomain protein on their promoters. These results conclude that the homeodomain protein Scr is transcriptionally involved in the regulation of JH biosynthesis in the silkworm.

  5. Juvenile hormone connects larval nutrition with target of rapamycin signaling in the mosquito Aedes aegypti.

    PubMed

    Shiao, Shin-Hong; Hansen, Immo A; Zhu, Jinsong; Sieglaff, Douglas H; Raikhel, Alexander S

    2008-01-01

    Anautogenous mosquitoes require blood meals to promote egg development. If adequate nutrients are not obtained during larval development, the resulting "small" sized adult mosquitoes require multiple blood meals for egg development; markedly increasing host-vector contacts and the likelihood of disease transmission. Nutrient-sensitive target of rapamycin (TOR) signaling is a key signaling pathway that links elevated hemolymph amino acid levels derived from the blood meal to the expression of yolk protein precursors in the fat body. Here we report that the blood-meal-induced activation of the TOR-signaling pathway and subsequent egg maturation depends on the accumulation of adequate nutritional reserves during larval development. We have established well-nourished, "standard" mosquitoes and malnourished, "small" mosquitoes as models to address this nutrient sensitive pathway. This regulatory mechanism involves juvenile hormone (JH), which acts as a mediator of fat body competence, permitting the response to amino acids derived from the blood meal. We demonstrate that treatment with JH results in recovery of the TOR molecular machinery, Aedes aegypti cationic amino acid transporter 2 (AaiCAT2), TOR, and S6 kinase (S6K), in fat bodies of small mosquitoes, enabling them to complete their first gonotrophic cycle after a single blood meal. These findings establish a direct link between nutrient reserves and the establishment of TOR signaling in mosquitoes.

  6. Gonadotropic and Physiological Functions of Juvenile Hormone in Bumblebee (Bombus terrestris) Workers

    PubMed Central

    Shpigler, Hagai; Amsalem, Etya; Huang, Zachary Y.; Cohen, Mira; Siegel, Adam J.; Hefetz, Abraham; Bloch, Guy

    2014-01-01

    The evolution of advanced sociality in bees is associated with apparent modifications in juvenile hormone (JH) signaling. By contrast to most insects in which JH is a gonadotropin regulating female fertility, in the highly eusocial honey bee (Apis mellifera) JH has lost its gonadotrophic function in adult females, and instead regulates age-related division of labor among worker bees. In order to shed light on the evolution of JH signaling in bees we performed allatectomy and replacement therapies to manipulate JH levels in workers of the "primitively eusocial" bumblebee Bombus terrestris. Allatectomized worker bees showed remarkable reduction in ovarian development, egg laying, Vitellogenin and Krüppel homolog 1 fat body transcript levels, hemolymph Vitellogenin protein abundance, wax secretion, and egg-cell construction. These effects were reverted, at least partially, by treating allatectomized bees with JH-III, the natural JH of bees. Allatectomy also affected the amount of ester component in Dufour's gland secretion, which is thought to convey a social signal relating to worker fertility. These findings provide a strong support for the hypothesis that in contrast to honey bees, JH is a gonadotropin in bumblebees and lend credence to the hypothesis that the evolution of advanced eusociality in honey bees was associated with major modifications in JH signaling. PMID:24959888

  7. Homeodomain Protein Scr Regulates the Transcription of Genes Involved in Juvenile Hormone Biosynthesis in the Silkworm

    PubMed Central

    Meng, Meng; Liu, Chun; Peng, Jian; Qian, Wenliang; Qian, Heying; Tian, Ling; Li, Jiarui; Dai, Dandan; Xu, Anying; Li, Sheng; Xia, Qingyou; Cheng, Daojun

    2015-01-01

    The silkworm Dominant trimolting (Moltinism, M3) mutant undergoes three larval molts and exhibits precocious metamorphosis. In this study, we found that compared with the wild-type (WT) that undergoes four larval molts, both the juvenile hormone (JH) concentration and the expression of the JH-responsive gene Krüppel homolog 1 (Kr-h1) began to be greater in the second instar of the M3 mutant. A positional cloning analysis revealed that only the homeodomain transcription factor gene Sex combs reduced (Scr) is located in the genomic region that is tightly linked to the M3 locus. The expression level of the Scr gene in the brain-corpora cardiaca-corpora allata (Br-CC-CA) complex, which controls the synthesis of JH, was very low in the final larval instar of both the M3 and WT larvae, and exhibited a positive correlation with JH titer changes. Importantly, luciferase reporter analysis and electrophoretic mobility shift assay (EMSA) demonstrated that the Scr protein could promote the transcription of genes involved in JH biosynthesis by directly binding to the cis-regulatory elements (CREs) of homeodomain protein on their promoters. These results conclude that the homeodomain protein Scr is transcriptionally involved in the regulation of JH biosynthesis in the silkworm. PMID:26540044

  8. Identification of plant compounds that disrupt the insect juvenile hormone receptor complex

    PubMed Central

    Lee, Seok-Hee; Oh, Hyun-Woo; Fang, Ying; An, Saes-Byeol; Park, Doo-Sang; Song, Hyuk-Hwan; Oh, Sei-Ryang; Kim, Soo-Young; Kim, Seonghyun; Kim, Namjung; Raikhel, Alexander S.; Je, Yeon Ho; Shin, Sang Woon

    2015-01-01

    Insects impact human health through vector-borne diseases and cause major economic losses by damaging crops and stored agricultural products. Insect-specific growth regulators represent attractive control agents because of their safety to the environment and humans. We identified plant compounds that serve as juvenile hormone antagonists (PJHANs). Using the yeast two-hybrid system transformed with the mosquito JH receptor as a reporter system, we demonstrate that PJHANs affect the JH receptor, methoprene-tolerant (Met), by disrupting its complex with CYCLE or FISC, formation of which is required for mediating JH action. We isolated five diterpene secondary metabolites with JH antagonist activity from two plants: Lindera erythrocarpa and Solidago serotina. They are effective in causing mortality of mosquito larvae at relatively low LD50 values. Topical application of two diterpenes caused reduction in the expression of Met target genes and retardation of follicle development in mosquito ovaries. Hence, the newly discovered PJHANs may lead to development of a new class of safe and effective pesticides. PMID:25624480

  9. Role of juvenile hormone and allatotropin on nutrient allocation, ovarian development and survivorship in mosquitoes

    PubMed Central

    Hernández-Martínez, Salvador; Mayoral, Jaime G.; Li, Yiping; Noriega, Fernando G.

    2009-01-01

    Teneral reserves are utilized to initiate previtellogenic ovarian development in mosquitoes. Females having emerged with low teneral reserves have reduced juvenile hormone (JH) synthesis and previtellogenic development. We investigated what role JH, allatotropin (AT) and other head-factors play in the regulation of previtellogenic ovarian development and adult survivorship. Factors from the head are essential for corpora allata (CA) activation and reproductive maturation. We have shown that decapitation of females within 9–12 h after adult ecdysis prevented normal development of the previtellogenic follicles; however maximum previtellogenic ovarian development could be induced in decapitated females by topically applying a JH analog. When females were decapitated 12 or more hours after emergence nutritional resources had been committed to ovarian development and survivorship was significantly reduced. To study if allatotropin levels correlated with teneral reserves, we measured AT titers in the heads of two adult phenotypes (large and small females) generated by raising larvae under different nutritional diets. In large mosquitoes AT levels increased to a maximum of 45 fmol in day 4; in contrast, the levels of allatotropin in the heads of small mosquitoes remained below 9 fmol during the 7 days evaluated. These results suggest that only when nutrients are appropriate, factors released from the brain induce the CA to synthesize enough JH to activate reproductive maturation. PMID:17070832

  10. Role of juvenile hormone and allatotropin on nutrient allocation, ovarian development and survivorship in mosquitoes.

    PubMed

    Hernández-Martínez, Salvador; Mayoral, Jaime G; Li, Yiping; Noriega, Fernando G

    2007-03-01

    Teneral reserves are utilized to initiate previtellogenic ovarian development in mosquitoes. Females having emerged with low teneral reserves have reduced juvenile hormone (JH) synthesis and previtellogenic development. We investigated what role JH, allatotropin (AT) and other head-factors play in the regulation of previtellogenic ovarian development and adult survivorship. Factors from the head are essential for corpora allata (CA) activation and reproductive maturation. We have shown that decapitation of females within 9-12h after adult ecdysis prevented normal development of the previtellogenic follicles; however maximum previtellogenic ovarian development could be induced in decapitated females by topically applying a JH analog. When females were decapitated 12 or more hours after emergence nutritional resources had been committed to ovarian development and survivorship was significantly reduced. To study if allatotropin levels correlated with teneral reserves, we measured AT titers in the heads of two adult phenotypes (large and small females) generated by raising larvae under different nutritional diets. In large mosquitoes AT levels increased to a maximum of 45 fmol in day 4; in contrast, the levels of allatotropin in the heads of small mosquitoes remained below 9 fmol during the 7 days evaluated. These results suggest that only when nutrients are appropriate, factors released from the brain induce the CA to synthesize enough JH to activate reproductive maturation.

  11. The role of juvenile hormone in competition and cooperation by burying beetles.

    PubMed

    Scott, Michelle Pellissier

    2006-10-01

    Few studies have addressed the physiological mechanisms that modulate aggression in insects. In some social insects, there is a correlation of JH and aggression in colony defense and in the establishment of dominance, but only a few studies demonstrate a causal relationship. Burying beetles aggressively defend a breeding resource, a carcass, and juvenile hormone (JH) hemolymph titers increase rapidly upon the discovery of a carcass. In this study, I show that treatment with the JH analog, methoprene, in the absence of a carcass increases the probability of injuries from aggressive interactions, but treatment to one member of a pair of competing Nicrophorus orbicollis females does not increase the probability that she will win control of the resource. In addition, higher JH levels are not associated with greater competitive ability in communally breeding Nicrophorus tomentosus females. Treatment of one female N. tomentosus does not increase her share of the communal brood. Methoprene seems to make a less competitive female more persistent and less willing to concede, which, although maintaining her share of reproduction, results in her exclusion from the brood chamber.

  12. Galanin synaptic input to gonadotropin-releasing hormone perikarya in juvenile and adult female mice: implications for sexual maturity.

    PubMed

    Rajendren, G; Li, X

    2001-11-26

    Changes in connectivity of the gonadotropin-releasing hormone (GnRH) neuronal system are believed to occur during the transition from juvenile to adulthood in females. Experiments were designed to investigate whether there is any difference in the number of galanin inputs to GnRH cells located in the organum vasculosum of lamina terminalis-rostral preoptic area (OVLT-rPOA) between juvenile (2 weeks old) and adult (10 weeks old) female mice. Triple label immunofluorescence staining of brain sections for galanin, GnRH and the presynaptic vesicle marker synaptophysin coupled with confocal microscopy was employed to identify galanin synapses to GnRH perikarya. The number of galanin synapses to GnRH cells and the proportion of GnRH cells with galanin input were significantly higher in adults than in juvenile mice. In adult mice, the proportions of GnRH cells with 0, 1, 2, 3, 4, 5 or 6 galanin synapses/cell were comparable to each other whereas in the juveniles the vast majority of them received no galanin synaptic input. A greater number of galanin synapses in adult as compared with juvenile female mice suggests a functional role for galanin in the maturation of the GnRH system.

  13. Hormonal alterations in PCOS and its influence on bone metabolism.

    PubMed

    Krishnan, Abhaya; Muthusami, Sridhar

    2017-02-01

    According to the World Health Organization (WHO) polycystic ovary syndrome (PCOS) occurs in 4-8% of women worldwide. The prevalence of PCOS in Indian adolescents is 12.2% according to the Indian Council of Medical Research (ICMR). The National Institute of Health has documented that it affects approximately 5 million women of reproductive age in the United States. Hormonal imbalance is the characteristic of many women with polycystic ovarian syndrome (PCOS). The influence of various endocrine changes in PCOS women and their relevance to bone remains to be documented. Hormones, which include gonadotrophin-releasing hormone (GnRH), insulin, the leutinizing/follicle-stimulating hormone (LH/FSH) ratio, androgens, estrogens, growth hormones (GH), cortisol, parathyroid hormone (PTH) and calcitonin are disturbed in PCOS women. These hormones influence bone metabolism in human subjects directly as well as indirectly. The imbalance in these hormones results in increased prevalence of osteoporosis in PCOS women. Limited evidence suggests that the drugs taken during the treatment of PCOS increase the risk of bone fracture in PCOS patients through endocrine disruption. This review is aimed at the identification of the relationship between bone mineral density and hormonal changes in PCOS subjects and identifies potential areas to study bone-related disorders in PCOS women.

  14. A new method of detecting hormone-binding proteins electroblotted onto glass fiber filter: juvenile hormone-binding proteins from grasshopper hemolymph.

    PubMed

    Jefferies, L S; Roberts, P E

    1990-03-01

    We have developed a new method to identify juvenile hormone (JH)-binding proteins blotted onto glass fiber filter (GFF) after electrophoretic separation. Insect JH regulates reproduction in the two-striped grasshopper, Melanoplus bivittatus. A number of proteins are involved in the delivery of JH from its site of synthesis to the nuclei of fat body cells where it acts to induce vitellogenesis. To identify JH binding proteins, hemolymph was separated by PAGE, electroblotted onto GFF, and incubated in [10-3H]JH-III. The amount of hormone bound by blotted proteins increased with the amount of protein on the filter, was competitively displaced by excess non-labeled hormone, and was affiliated with individual bands on fluorograms of proteins blotted after electrophoretic separation. GFF etched with trifluoroacetic acid was better than nitrocellulose, Zeta Probe, cellulose acetate or unetched GFF. Phosphate (pH 6.0-7.3) or Tris buffers (pH 7.3-8.0) worked equally well for the procedure. Unbound hormone was easily removed by short washes in buffer, and adequate binding for detection was achieved in a 15 min incubation. Preliminary data suggest that this technique may be used to detect receptors, carriers, and binding proteins of steroid hormones.

  15. Juvenile hormone and insulin suppress lipolysis between periods of lactation during tsetse fly pregnancy.

    PubMed

    Baumann, Aaron A; Benoit, Joshua B; Michalkova, Veronika; Mireji, Paul O; Attardo, Geoffrey M; Moulton, John K; Wilson, Thomas G; Aksoy, Serap

    2013-06-15

    Tsetse flies are viviparous insects that nurture a single intrauterine progeny per gonotrophic cycle. The developing larva is nourished by the lipid-rich, milk-like secretions from a modified female accessory gland (milk gland). An essential feature of the lactation process involves lipid mobilization for incorporation into the milk. In this study, we examined roles for juvenile hormone (JH) and insulin/IGF-like (IIS) signaling pathways during tsetse pregnancy. In particular, we examined the roles for these pathways in regulating lipid homeostasis during transitions between non-lactating (dry) and lactating periods. The dry period occurs over the course of oogenesis and embryogenesis, while the lactation period spans intrauterine larvigenesis. Genes involved in the JH and IIS pathways were upregulated during dry periods, correlating with lipid accumulation between bouts of lactation. RNAi suppression of Forkhead Box Sub Group O (FOXO) expression impaired lipolysis during tsetse lactation and reduced fecundity. Similar reduction of the JH receptor Methoprene tolerant (Met), but not its paralog germ cell expressed (gce), reduced lipid accumulation during dry periods, indicating functional divergence between Met and gce during tsetse reproduction. Reduced lipid levels following Met knockdown led to impaired fecundity due to inadequate fat reserves at the initiation of milk production. Both the application of the JH analog (JHA) methoprene and injection of insulin into lactating females increased stored lipids by suppressing lipolysis and reduced transcripts of lactation-specific genes, leading to elevated rates of larval abortion. To our knowledge, this study is the first to address the molecular physiology of JH and IIS in a viviparous insect, and specifically to provide a role for JH signaling through Met in the regulation of lipid metabolism during insect lactation.

  16. A role for juvenile hormone in the prepupal development of Drosophila melanogaster.

    PubMed

    Riddiford, Lynn M; Truman, James W; Mirth, Christen K; Shen, Yu-Chi

    2010-04-01

    To elucidate the role of juvenile hormone (JH) in metamorphosis of Drosophila melanogaster, the corpora allata cells, which produce JH, were killed using the cell death gene grim. These allatectomized (CAX) larvae were smaller at pupariation and died at head eversion. They showed premature ecdysone receptor B1 (EcR-B1) in the photoreceptors and in the optic lobe, downregulation of proliferation in the optic lobe, and separation of R7 from R8 in the medulla during the prepupal period. All of these effects of allatectomy were reversed by feeding third instar larvae on a diet containing the JH mimic (JHM) pyriproxifen or by application of JH III or JHM at the onset of wandering. Eye and optic lobe development in the Methoprene-tolerant (Met)-null mutant mimicked that of CAX prepupae, but the mutant formed viable adults, which had marked abnormalities in the organization of their optic lobe neuropils. Feeding Met(27) larvae on the JHM diet did not rescue the premature EcR-B1 expression or the downregulation of proliferation but did partially rescue the premature separation of R7, suggesting that other pathways besides Met might be involved in mediating the response to JH. Selective expression of Met RNAi in the photoreceptors caused their premature expression of EcR-B1 and the separation of R7 and R8, but driving Met RNAi in lamina neurons led only to the precocious appearance of EcR-B1 in the lamina. Thus, the lack of JH and its receptor Met causes a heterochronic shift in the development of the visual system that is likely to result from some cells 'misinterpreting' the ecdysteroid peaks that drive metamorphosis.

  17. TGF-β signaling in insects regulates metamorphosis via juvenile hormone biosynthesis.

    PubMed

    Ishimaru, Yoshiyasu; Tomonari, Sayuri; Matsuoka, Yuji; Watanabe, Takahito; Miyawaki, Katsuyuki; Bando, Tetsuya; Tomioka, Kenji; Ohuchi, Hideyo; Noji, Sumihare; Mito, Taro

    2016-05-17

    Although butterflies undergo a dramatic morphological transformation from larva to adult via a pupal stage (holometamorphosis), crickets undergo a metamorphosis from nymph to adult without formation of a pupa (hemimetamorphosis). Despite these differences, both processes are regulated by common mechanisms that involve 20-hydroxyecdysone (20E) and juvenile hormone (JH). JH regulates many aspects of insect physiology, such as development, reproduction, diapause, and metamorphosis. Consequently, strict regulation of JH levels is crucial throughout an insect's life cycle. However, it remains unclear how JH synthesis is regulated. Here, we report that in the corpora allata of the cricket, Gryllus bimaculatus, Myoglianin (Gb'Myo), a homolog of Drosophila Myoglianin/vertebrate GDF8/11, is involved in the down-regulation of JH production by suppressing the expression of a gene encoding JH acid O-methyltransferase, Gb'jhamt In contrast, JH production is up-regulated by Decapentaplegic (Gb'Dpp) and Glass-bottom boat/60A (Gb'Gbb) signaling that occurs as part of the transcriptional activation of Gb'jhamt Gb'Myo defines the nature of each developmental transition by regulating JH titer and the interactions between JH and 20E. When Gb'myo expression is suppressed, the activation of Gb'jhamt expression and secretion of 20E induce molting, thereby leading to the next instar before the last nymphal instar. Conversely, high Gb'myo expression induces metamorphosis during the last nymphal instar through the cessation of JH synthesis. Gb'myo also regulates final insect size. Because Myo/GDF8/11 and Dpp/bone morphogenetic protein (BMP)2/4-Gbb/BMP5-8 are conserved in both invertebrates and vertebrates, the present findings provide common regulatory mechanisms for endocrine control of animal development.

  18. MiR-2 family regulates insect metamorphosis by controlling the juvenile hormone signaling pathway.

    PubMed

    Lozano, Jesus; Montañez, Raúl; Belles, Xavier

    2015-03-24

    In 2009 we reported that depletion of Dicer-1, the enzyme that catalyzes the final step of miRNA biosynthesis, prevents metamorphosis in Blattella germanica. However, the precise regulatory roles of miRNAs in the process have remained elusive. In the present work, we have observed that Dicer-1 depletion results in an increase of mRNA levels of Krüppel homolog 1 (Kr-h1), a juvenile hormone-dependent transcription factor that represses metamorphosis, and that depletion of Kr-h1 expression in Dicer-1 knockdown individuals rescues metamorphosis. We have also found that the 3'UTR of Kr-h1 mRNA contains a functional binding site for miR-2 family miRNAs (for miR-2, miR-13a, and miR-13b). These data suggest that metamorphosis impairment caused by Dicer-1 and miRNA depletion is due to a deregulation of Kr-h1 expression and that this deregulation is derived from a deficiency of miR-2 miRNAs. We corroborated this by treating the last nymphal instar of B. germanica with an miR-2 inhibitor, which impaired metamorphosis, and by treating Dicer-1-depleted individuals with an miR-2 mimic to allow nymphal-to-adult metamorphosis to proceed. Taken together, the data indicate that miR-2 miRNAs scavenge Kr-h1 transcripts when the transition from nymph to adult should be taking place, thus crucially contributing to the correct culmination of metamorphosis.

  19. TGF-β signaling in insects regulates metamorphosis via juvenile hormone biosynthesis

    PubMed Central

    Ishimaru, Yoshiyasu; Tomonari, Sayuri; Matsuoka, Yuji; Watanabe, Takahito; Miyawaki, Katsuyuki; Bando, Tetsuya; Tomioka, Kenji; Ohuchi, Hideyo; Noji, Sumihare; Mito, Taro

    2016-01-01

    Although butterflies undergo a dramatic morphological transformation from larva to adult via a pupal stage (holometamorphosis), crickets undergo a metamorphosis from nymph to adult without formation of a pupa (hemimetamorphosis). Despite these differences, both processes are regulated by common mechanisms that involve 20-hydroxyecdysone (20E) and juvenile hormone (JH). JH regulates many aspects of insect physiology, such as development, reproduction, diapause, and metamorphosis. Consequently, strict regulation of JH levels is crucial throughout an insect’s life cycle. However, it remains unclear how JH synthesis is regulated. Here, we report that in the corpora allata of the cricket, Gryllus bimaculatus, Myoglianin (Gb’Myo), a homolog of Drosophila Myoglianin/vertebrate GDF8/11, is involved in the down-regulation of JH production by suppressing the expression of a gene encoding JH acid O-methyltransferase, Gb’jhamt. In contrast, JH production is up-regulated by Decapentaplegic (Gb’Dpp) and Glass-bottom boat/60A (Gb’Gbb) signaling that occurs as part of the transcriptional activation of Gb’jhamt. Gb’Myo defines the nature of each developmental transition by regulating JH titer and the interactions between JH and 20E. When Gb’myo expression is suppressed, the activation of Gb’jhamt expression and secretion of 20E induce molting, thereby leading to the next instar before the last nymphal instar. Conversely, high Gb’myo expression induces metamorphosis during the last nymphal instar through the cessation of JH synthesis. Gb’myo also regulates final insect size. Because Myo/GDF8/11 and Dpp/bone morphogenetic protein (BMP)2/4-Gbb/BMP5–8 are conserved in both invertebrates and vertebrates, the present findings provide common regulatory mechanisms for endocrine control of animal development. PMID:27140602

  20. Bumblebees can be used in combination with juvenile hormone analogues and ecdysone agonists.

    PubMed

    Mommaerts, Veerle; Sterk, Guido; Smagghe, Guy

    2006-08-01

    This study examined the lethal and sublethal effects on the beneficial insect Bombus terrestris by two classes of insect growth regulators (IGRs) that are commercially used in agriculture to control pest insects. Three juvenile hormones analogues (JHAs) (pyriproxyfen, fenoxycarb and kinoprene) and two ecdysone agonists or moulting accelerating compounds (MACs) (tebufenozide and methoxyfenozide) were tested. The bumblebee workers were exposed to the insecticides via three different routes of exposure: dermally by topical contact, and orally via the drinking sugar water or the pollen. In the first series of experiments the IGRs were applied at their respective maximum field recommended concentration (MFRC). These risk hazard tests showed that the tested IGRs caused no acute toxicity on the workers, and any compound had an adverse effect on reproduction (production of males). In addition, larval development was followed in the treated nests compared with the controls. After application of the two MACs and the JHA fenoxycarb no adverse effects were observed on larval development. However, in the nests where the workers were exposed to the JHAs pyriproxyfen and kinoprene higher numbers of dead larvae were scored. These larvae were third and fourth instars, implying a lethal blockage of development before metamorphosis. In a second test, a series of dilutions was made for kinoprene, and these results revealed that only the MFRC caused a toxic effect on the larval development. On the other hand, kinoprene at lower concentrations (0.0650 mg ai/l) had a stimulatory effect on brood production. It was remarkable that ovaries of such treated dominant workers were longer and contained more eggs than in the controls. In a last experiment, the cuticular uptake was determined for a JHA and MAC to evaluate to what extent worker bees accumulate these classes of IGRs. Cuticular uptake ranged from 34 to 83% at 24 h after topical application. Overall, the obtained results indicate that

  1. MiR-2 family regulates insect metamorphosis by controlling the juvenile hormone signaling pathway

    PubMed Central

    Belles, Xavier

    2015-01-01

    In 2009 we reported that depletion of Dicer-1, the enzyme that catalyzes the final step of miRNA biosynthesis, prevents metamorphosis in Blattella germanica. However, the precise regulatory roles of miRNAs in the process have remained elusive. In the present work, we have observed that Dicer-1 depletion results in an increase of mRNA levels of Krüppel homolog 1 (Kr-h1), a juvenile hormone-dependent transcription factor that represses metamorphosis, and that depletion of Kr-h1 expression in Dicer-1 knockdown individuals rescues metamorphosis. We have also found that the 3′UTR of Kr-h1 mRNA contains a functional binding site for miR-2 family miRNAs (for miR-2, miR-13a, and miR-13b). These data suggest that metamorphosis impairment caused by Dicer-1 and miRNA depletion is due to a deregulation of Kr-h1 expression and that this deregulation is derived from a deficiency of miR-2 miRNAs. We corroborated this by treating the last nymphal instar of B. germanica with an miR-2 inhibitor, which impaired metamorphosis, and by treating Dicer-1-depleted individuals with an miR-2 mimic to allow nymphal-to-adult metamorphosis to proceed. Taken together, the data indicate that miR-2 miRNAs scavenge Kr-h1 transcripts when the transition from nymph to adult should be taking place, thus crucially contributing to the correct culmination of metamorphosis. PMID:25775510

  2. A cytochrome P450 terpenoid hydroxylase linked to the suppression of insect juvenile hormone synthesis.

    PubMed

    Sutherland, T D; Unnithan, G C; Andersen, J F; Evans, P H; Murataliev, M B; Szabo, L Z; Mash, E A; Bowers, W S; Feyereisen, R

    1998-10-27

    A cDNA encoding a cytochrome P450 enzyme was isolated from a cDNA library of the corpora allata (CA) from reproductively active Diploptera punctata cockroaches. This P450 from the endocrine glands that produce the insect juvenile hormone (JH) is most closely related to P450 proteins of family 4 and was named CYP4C7. The CYP4C7 gene is expressed selectively in the CA; its message could not be detected in the fat body, corpora cardiaca, or brain, but trace levels of expression were found in the midgut and caeca. The levels of CYP4C7 mRNA in the CA, measured by ribonuclease protection assays, were linked to the activity cycle of the glands. In adult females, CYP4C7 expression increased immediately after the peak of JH synthesis, reaching a maximum on day 7, just before oviposition. mRNA levels then declined after oviposition and during pregnancy. The CYP4C7 protein was produced in Escherichia coli as a C-terminal His-tagged recombinant protein. In a reconstituted system with insect NADPH cytochrome P450 reductase, cytochrome b5, and NADPH, the purified CYP4C7 metabolized (2E,6E)-farnesol to a more polar product that was identified by GC-MS and by NMR as (10E)-12-hydroxyfarnesol. CYP4C7 converted JH III to 12-trans-hydroxy JH III and metabolized other JH-like sesquiterpenoids as well. This omega-hydroxylation of sesquiterpenoids appears to be a metabolic pathway in the corpora allata that may play a role in the suppression of JH biosynthesis at the end of the gonotrophic cycle.

  3. Molecular mechanism underlying juvenile hormone-mediated repression of precocious larval–adult metamorphosis

    PubMed Central

    Kayukawa, Takumi; Jouraku, Akiya; Ito, Yuka; Shinoda, Tetsuro

    2017-01-01

    Juvenile hormone (JH) represses precocious metamorphosis of larval to pupal and adult transitions in holometabolous insects. The early JH-inducible gene Krüppel homolog 1 (Kr-h1) plays a key role in the repression of metamorphosis as a mediator of JH action. Previous studies demonstrated that Kr-h1 inhibits precocious larval–pupal transition in immature larva via direct transcriptional repression of the pupal specifier Broad-Complex (BR-C). JH was recently reported to repress the adult specifier gene Ecdysone-induced protein 93F (E93); however, its mechanism of action remains unclear. Here, we found that JH suppressed ecdysone-inducible E93 expression in the epidermis of the silkworm Bombyx mori and in a B. mori cell line. Reporter assays in the cell line revealed that the JH-dependent suppression was mediated by Kr-h1. Genome-wide ChIP-seq analysis identified a consensus Kr-h1 binding site (KBS, 14 bp) located in the E93 promoter region, and EMSA confirmed that Kr-h1 directly binds to the KBS. Moreover, we identified a C-terminal conserved domain in Kr-h1 essential for the transcriptional repression of E93. Based on these results, we propose a mechanism in which JH-inducible Kr-h1 directly binds to the KBS site upstream of the E93 locus to repress its transcription in a cell-autonomous manner, thereby preventing larva from bypassing the pupal stage and progressing to precocious adult development. These findings help to elucidate the molecular mechanisms regulating the metamorphic genetic network, including the functional significance of Kr-h1, BR-C, and E93 in holometabolous insect metamorphosis. PMID:28096379

  4. Hairy and Groucho mediate the action of juvenile hormone receptor Methoprene-tolerant in gene repression

    PubMed Central

    Saha, Tusar T.; Shin, Sang Woon; Dou, Wei; Roy, Sourav; Zhao, Bo; Hou, Yuan; Wang, Xue-Li; Zou, Zhen; Girke, Thomas; Raikhel, Alexander S.

    2016-01-01

    The arthropod-specific juvenile hormone (JH) controls numerous essential functions. Its involvement in gene activation is known to be mediated by the transcription factor Methoprene-tolerant (Met), which turns on JH-controlled genes by directly binding to E-box–like motifs in their regulatory regions. However, it remains unclear how JH represses genes. We used the Aedes aegypti female mosquito, in which JH is necessary for reproductive maturation, to show that a repressor, Hairy, is required for the gene-repressive action of JH and Met. The RNA interference (RNAi) screen for Met and Hairy in the Aedes female fat body revealed a large cohort of Met- and Hairy-corepressed genes. Analysis of selected genes from this cohort demonstrated that they are repressed by JH, but RNAi of either Met or Hairy renders JH ineffective in repressing these genes in an in vitro fat-body culture assay. Moreover, this JH action was prevented by the addition of the translational inhibitor cycloheximide (CHX) to the culture, indicating the existence of an indirect regulatory hierarchy. The lack of Hairy protein in the CHX-treated tissue was verified using immunoblot analysis, and the upstream regions of Met/Hairy-corepressed genes were shown to contain common binding motifs that interact with Hairy. Groucho (gro) RNAi silencing phenocopied the effect of Hairy RNAi knockdown, indicating that it is involved in the JH/Met/Hairy hierarchy. Finally, the requirement of Hairy and Gro for gene repression was confirmed in a cell transfection assay. Thus, our study has established that Hairy and its cofactor Gro mediate the repressive function of JH and Met. PMID:26744312

  5. Influences of Neighborhood Context, Individual History and Parenting Behavior on Recidivism among Juvenile Offenders

    ERIC Educational Resources Information Center

    Grunwald, Heidi E.; Lockwood, Brian; Harris, Philip W.; Mennis, Jeremy

    2010-01-01

    This study examined the effects of neighborhood context on juvenile recidivism to determine if neighborhoods influence the likelihood of reoffending. Although a large body of literature exists regarding the impact of environmental factors on delinquency, very little is known about the effects of these factors on juvenile recidivism. The sample…

  6. Modeling the flux of metabolites in the juvenile hormone biosynthesis pathway using generalized additive models and ordinary differential equations.

    PubMed

    Martínez-Rincón, Raúl O; Rivera-Pérez, Crisalejandra; Diambra, Luis; Noriega, Fernando G

    2017-01-01

    Juvenile hormone (JH) regulates development and reproductive maturation in insects. The corpora allata (CA) from female adult mosquitoes synthesize fluctuating levels of JH, which have been linked to the ovarian development and are influenced by nutritional signals. The rate of JH biosynthesis is controlled by the rate of flux of isoprenoids in the pathway, which is the outcome of a complex interplay of changes in precursor pools and enzyme levels. A comprehensive study of the changes in enzymatic activities and precursor pool sizes have been previously reported for the mosquito Aedes aegypti JH biosynthesis pathway. In the present studies, we used two different quantitative approaches to describe and predict how changes in the individual metabolic reactions in the pathway affect JH synthesis. First, we constructed generalized additive models (GAMs) that described the association between changes in specific metabolite concentrations with changes in enzymatic activities and substrate concentrations. Changes in substrate concentrations explained 50% or more of the model deviances in 7 of the 13 metabolic steps analyzed. Addition of information on enzymatic activities almost always improved the fitness of GAMs built solely based on substrate concentrations. GAMs were validated using experimental data that were not included when the model was built. In addition, a system of ordinary differential equations (ODE) was developed to describe the instantaneous changes in metabolites as a function of the levels of enzymatic catalytic activities. The results demonstrated the ability of the models to predict changes in the flux of metabolites in the JH pathway, and can be used in the future to design and validate experimental manipulations of JH synthesis.

  7. Modeling the flux of metabolites in the juvenile hormone biosynthesis pathway using generalized additive models and ordinary differential equations

    PubMed Central

    Martínez-Rincón, Raúl O.; Rivera-Pérez, Crisalejandra; Diambra, Luis; Noriega, Fernando G.

    2017-01-01

    Juvenile hormone (JH) regulates development and reproductive maturation in insects. The corpora allata (CA) from female adult mosquitoes synthesize fluctuating levels of JH, which have been linked to the ovarian development and are influenced by nutritional signals. The rate of JH biosynthesis is controlled by the rate of flux of isoprenoids in the pathway, which is the outcome of a complex interplay of changes in precursor pools and enzyme levels. A comprehensive study of the changes in enzymatic activities and precursor pool sizes have been previously reported for the mosquito Aedes aegypti JH biosynthesis pathway. In the present studies, we used two different quantitative approaches to describe and predict how changes in the individual metabolic reactions in the pathway affect JH synthesis. First, we constructed generalized additive models (GAMs) that described the association between changes in specific metabolite concentrations with changes in enzymatic activities and substrate concentrations. Changes in substrate concentrations explained 50% or more of the model deviances in 7 of the 13 metabolic steps analyzed. Addition of information on enzymatic activities almost always improved the fitness of GAMs built solely based on substrate concentrations. GAMs were validated using experimental data that were not included when the model was built. In addition, a system of ordinary differential equations (ODE) was developed to describe the instantaneous changes in metabolites as a function of the levels of enzymatic catalytic activities. The results demonstrated the ability of the models to predict changes in the flux of metabolites in the JH pathway, and can be used in the future to design and validate experimental manipulations of JH synthesis. PMID:28158248

  8. Hormones in the field: evolutionary endocrinology of juvenile hormone and ecdysteroids in field populations of the wing-dimorphic cricket Gryllus firmus.

    PubMed

    Zera, Anthony J; Zhao, Zangwu; Kaliseck, Katherine

    2007-01-01

    Virtually no published information exists on insect endocrine traits in natural populations, which limits our understanding of endocrine microevolution. We characterized the hemolymph titers of juvenile hormone (JH) and ecdysteroids (ECDs), two key insect hormones, in field-collected short-winged, flightless (SW) and long-winged, flight-capable (LW(f)) morphs of the cricket Gryllus firmus. The JH titer exhibited a dramatic circadian rhythm in the LW(f) morph but was temporally constant in the flightless SW morph. This pattern was consistent in each of three years; in young, middle-aged, and older G. firmus; and in three other cricket species. The ECD titer was considerably higher in SW than in LW(f) females but did not exhibit temporal variation in any morph and did not differ between male morphs. JH and ECD may control different aspects of the morph-specific trade-off between nocturnal dispersal and reproduction. Results confirm and extend laboratory studies on young female G. firmus; most, but not all, important aspects of morph-specific differences in JH and ECD titers can be extrapolated from field to laboratory environments and vice versa. Hormone titers in Gryllus are more complex than those proposed in evolutionary endocrine models. Directly measuring hormone titer variation remains a fundamentally important task of insect evolutionary endocrinology.

  9. Evaluation of Juvenile Hormone Analogues as Rodent Feed-Through Insecticides for Control of Immature Phlebotomine Sandflies

    DTIC Science & Technology

    2011-01-01

    darkness, high relative humidity, protection from extreme temperatures ). Adult sandflies live in close proximity to sources of blood (from the rodents...through insecticides for control of immature phlebotomine sandflies T. M. M A S C A R I1, M. A. M I T C H E L L2, E. D. R O W T O N3 and L. D. F O I L1...juvenile hormone analogues methoprene and pyriproxyfen were evaluated as rodent feed-through insecticides for control of immature stages of the sandfly

  10. Pleiotropic effects of juvenile hormone in ant queens and the escape from the reproduction-immunocompetence trade-off.

    PubMed

    Pamminger, Tobias; Treanor, David; Hughes, William O H

    2016-01-13

    The ubiquitous trade-off between survival and costly reproduction is one of the most fundamental constraints governing life-history evolution. In numerous animals, gonadotropic hormones antagonistically suppressing immunocompetence cause this trade-off. The queens of many social insects defy the reproduction-survival trade-off, achieving both an extraordinarily long life and high reproductive output, but how they achieve this is unknown. Here we show experimentally, by integrating quantification of gene expression, physiology and behaviour, that the long-lived queens of the ant Lasius niger have escaped the reproduction-immunocompetence trade-off by decoupling the effects of a key endocrine regulator of fertility and immunocompetence in solitary insects, juvenile hormone (JH). This modification of the regulatory architecture enables queens to sustain a high reproductive output without elevated JH titres and suppressed immunocompetence, providing an escape from the reproduction-immunocompetence trade-off that may contribute to the extraordinary lifespan of many social insect queens.

  11. Nutritional Signaling Regulates Vitellogenin Synthesis and Egg Development through Juvenile Hormone in Nilaparvata lugens (Stål)

    PubMed Central

    Lu, Kai; Chen, Xia; Liu, Wen-Ting; Zhang, Xin-Yu; Chen, Ming-Xiao; Zhou, Qiang

    2016-01-01

    Insect female reproduction which comprises the synthesis of vitellogenein (Vg) in the fat body and its incorporation into developing oocytes, needs a large amount of energy and food resources. Our previous studies found that juvenile hormone (JH) regulates vitellogenesis in the brown planthopper, Nilaparvata lugens. Here, we report on the role of JH in nutrient-regulated Vg synthesis and egg development. We first cloned the genes coding for juvenile hormone acid methyltransferase (JHAMT) which is involved in JH biosynthesis and methoprene-tolerant (Met) for JH action. Amino acids (AAs) induced the expression of jmtN, while showing no effects on the expression of met using an artificial diet culture system. Reduction in JH biosynthesis or its action by RNA interference (RNAi)-mediated silencing of jmtN or met led to a severe inhibition of AAs-induced Vg synthesis and oocyte maturation, together with lower fecundity. Furthermore, exogenous application of JH III partially restored Vg expression levels in jmtN RNAi females. However, JH III application did not rescue Vg synthesis in these met RNAi insects. Our results show that AAs induce Vg synthesis in the fat body and egg development in concert with JH biosynthesis in Nilaparvata lugens (Stål), rather than through JH action. PMID:26927076

  12. TOR Pathway-Mediated Juvenile Hormone Synthesis Regulates Nutrient-Dependent Female Reproduction in Nilaparvata lugens (Stål).

    PubMed

    Lu, Kai; Chen, Xia; Liu, Wen-Ting; Zhou, Qiang

    2016-03-28

    The "target of rapamycin" (TOR) nutritional signaling pathway and juvenile hormone (JH) regulation of vitellogenesis has been known for a long time. However, the interplay between these two pathways regulating vitellogenin (Vg) expression remains obscure. Here, we first demonstrated the key role of amino acids (AAs) in activation of Vg synthesis and egg development in Nilaparvata lugens using chemically defined artificial diets. AAs induced the expression of TOR and S6K (S6 kinase), whereas RNAi-mediated silencing of these two TOR pathway genes and rapamycin application strongly inhibited the AAs-induced Vg synthesis. Furthermore, knockdown of Rheb (Ras homologue enriched in brain), TOR, S6K and application of rapamycin resulted in a dramatic reduction in the mRNA levels of jmtN (juvenile hormone acid methyltransferase, JHAMT). Application of JH III on the RNAi (Rheb and TOR) and rapamycin-treated females partially rescued the Vg expression. Conversely, knockdown of either jmtN or met (methoprene-tolerant, JH receptor) and application of JH III had no effects on mRNA levels of Rheb, TOR and S6K and phosphorylation of S6K. In summary, our results demonstrate that the TOR pathway induces JH biosynthesis that in turn regulates AAs-mediated Vg synthesis in N. lugens.

  13. Nutritional Signaling Regulates Vitellogenin Synthesis and Egg Development through Juvenile Hormone in Nilaparvata lugens (Stål).

    PubMed

    Lu, Kai; Chen, Xia; Liu, Wen-Ting; Zhang, Xin-Yu; Chen, Ming-Xiao; Zhou, Qiang

    2016-02-26

    Insect female reproduction which comprises the synthesis of vitellogenein (Vg) in the fat body and its incorporation into developing oocytes, needs a large amount of energy and food resources. Our previous studies found that juvenile hormone (JH) regulates vitellogenesis in the brown planthopper, Nilaparvata lugens. Here, we report on the role of JH in nutrient-regulated Vg synthesis and egg development. We first cloned the genes coding for juvenile hormone acid methyltransferase (JHAMT) which is involved in JH biosynthesis and methoprene-tolerant (Met) for JH action. Amino acids (AAs) induced the expression of jmtN, while showing no effects on the expression of met using an artificial diet culture system. Reduction in JH biosynthesis or its action by RNA interference (RNAi)-mediated silencing of jmtN or met led to a severe inhibition of AAs-induced Vg synthesis and oocyte maturation, together with lower fecundity. Furthermore, exogenous application of JH III partially restored Vg expression levels in jmtN RNAi females. However, JH III application did not rescue Vg synthesis in these met RNAi insects. Our results show that AAs induce Vg synthesis in the fat body and egg development in concert with JH biosynthesis in Nilaparvata lugens (Stål), rather than through JH action.

  14. TOR Pathway-Mediated Juvenile Hormone Synthesis Regulates Nutrient-Dependent Female Reproduction in Nilaparvata lugens (Stål)

    PubMed Central

    Lu, Kai; Chen, Xia; Liu, Wen-Ting; Zhou, Qiang

    2016-01-01

    The “target of rapamycin” (TOR) nutritional signaling pathway and juvenile hormone (JH) regulation of vitellogenesis has been known for a long time. However, the interplay between these two pathways regulating vitellogenin (Vg) expression remains obscure. Here, we first demonstrated the key role of amino acids (AAs) in activation of Vg synthesis and egg development in Nilaparvata lugens using chemically defined artificial diets. AAs induced the expression of TOR and S6K (S6 kinase), whereas RNAi-mediated silencing of these two TOR pathway genes and rapamycin application strongly inhibited the AAs-induced Vg synthesis. Furthermore, knockdown of Rheb (Ras homologue enriched in brain), TOR, S6K and application of rapamycin resulted in a dramatic reduction in the mRNA levels of jmtN (juvenile hormone acid methyltransferase, JHAMT). Application of JH III on the RNAi (Rheb and TOR) and rapamycin-treated females partially rescued the Vg expression. Conversely, knockdown of either jmtN or met (methoprene-tolerant, JH receptor) and application of JH III had no effects on mRNA levels of Rheb, TOR and S6K and phosphorylation of S6K. In summary, our results demonstrate that the TOR pathway induces JH biosynthesis that in turn regulates AAs-mediated Vg synthesis in N. lugens. PMID:27043527

  15. Influence of female sex hormones on periodontium: A case series

    PubMed Central

    Jafri, Zeba; Bhardwaj, Ashu; Sawai, Madhuri; Sultan, Nishat

    2015-01-01

    Dental plaque is the primary etiologic factor for the periodontal diseases. Although pathogenic bacteria in dental plaque are necessary for the incidence of periodontal disease, but a susceptible host is as important. The susceptibility of the host can be modified by various systemic factors with hormones level being one. The periodontium shows an exaggerated inflammatory response to plaque modified by female sex hormone during puberty, pregnancy, in women taking oral contraceptives and at the postmenopausal stage. This paper presents such few cases where periodontium is influenced by variation in sex steroid hormones of female during different phases of their life time and to discuss how much a same hormone at different age and stage shows an exaggerated gingival response to plaque. PMID:26604605

  16. The nature and development of sex attractant specificity in cockroaches of the genus Periplaneta. IV. electrophysiological study of attractant specificity and its determination by juvenile hormone.

    PubMed

    Schafer, R

    1977-02-01

    The antennae of male Periplaneta americana acquire a large number of olfactory receptors at the adult stage. Electrophysiological methods (single unit and electroantennogram recording) show that a portion of the receptors added at the adult ecdysis are sex attractant receptors. Sex attractant receptors are not present in large numbers on larval and adult female antennae. The differentiation of pheromone receptors is inhibited during normal larval development by juvenile hormone. Topical application of juvenile hormone-mimic to male antennae during the terminal larval instar inhibits their development. Comparative electrophysiological studies indicate a high degree of cross-reactivity of the P. americana sex attractant among four other species within the genus Periplaneta.

  17. Developmental abnormalities of the gonad and abnormal sex hormone concentrations in juvenile alligators from contaminated and control lakes in Florida.

    PubMed Central

    Guillette, L J; Gross, T S; Masson, G R; Matter, J M; Percival, H F; Woodward, A R

    1994-01-01

    The reproductive development of alligators from a contaminated and a control lake in central Florida was examined. Lake Apopka is adjacent to an EPA Superfund site, listed due to an extensive spill of dicofol and DDT or its metabolites. These compounds can act as estrogens. Contaminants in the lake also have been derived from extensive agricultural activities around the lake that continue today and a sewage treatment facility associated with the city of Winter Garden, Florida. We examined the hypothesis that an estrogenic contaminant has caused the current failure in recruitment of alligators on Lake Apopka. Supporting data include the following: At 6 months of age, female alligators from Lake Apopka had plasma estradiol-17 beta concentrations almost two times greater than normal females from the control lake, Lake Woodruff. The Apopka females exhibited abnormal ovarian morphology with large numbers of polyovular follicles and polynuclear oocytes. Male juvenile alligators had significantly depressed plasma testosterone concentrations comparable to levels observed in normal Lake Woodruff females but more than three times lower than normal Lake Woodruff males. Additionally, males from Lake Apopka had poorly organized testes and abnormally small phalli. The differences between lakes and sexes in plasma hormone concentrations of juvenile alligators remain even after stimulation with luteinizing hormone. Our data suggest that the gonads of juveniles from Lake Apopka have been permanently modified in ovo, so that normal steroidogenesis is not possible, and thus normal sexual maturation is unlikely. Images p680-a Figure 1. Figure 2. Figure 3. A Figure 3. B Figure 3. C Figure 4. A Figure 4. B Figure 4. C Figure 4. D Figure 5. A Figure 5. B Figure 5. C PMID:7895709

  18. Immune Deficiency Influences Juvenile Social Behavior and Maternal Behavior

    PubMed Central

    Quinnies, Kayla M.; Cox, Kimberly H.; Rissman, Emilie F.

    2017-01-01

    Mice with severe combined immunodeficiency (SCID) lack functional T and B-lymphocytes, and have impaired cognitive abilities. Here, we assessed social behaviors in male SCID and C57BL/6 (B6) juvenile mice. In a social preference task, SCID mice spent more time than B6 mice investigating a novel adult male mouse. In a social recognition task, SCID mice habituated to a novel ovariectomized mouse, but failed to show dishabituation when presented with an unfamiliar individual. We hypothesized that partial immune restoration could normalize behaviors. SCID pups (postnatal day 7) received either saline or splenocytes from normal donors. Splenocyte-replaced SCID mice spent less time interacting with a novel mouse than saline-injected SCID or B6 control mice. Again, control SCID mice failed to dishabituate to a novel mouse, but splenocyte-replaced SCID mice showed dishabituation. In both of these studies B6 and SCID pairs were used to produce offspring that remained with their dams until weaning. There are no studies of maternal behavior in SCID dams; therefore to investigate the potential role for this factor we quantified maternal behavior in SCID and B6 dams; several significant differences were found. To control for differences in maternal care we mated heterozygous SCIDs to produce offspring. These homozygous SCID and WT offspring reared by dams of the same genotypes displayed similar responses to a novel mouse; however, in the social recognition task SCID males did not display dishabituation to a novel mouse. Taken together, our data indicate that gene by environment interactions influence social interactions in immune deficient mice. PMID:26030431

  19. Evolutionary genetics of juvenile hormone and ecdysteroid regulation in Gryllus: a case study in the microevolution of endocrine regulation.

    PubMed

    Zera, Anthony J

    2006-07-01

    During the past 15 years the first detailed synthesis of endocrinology and population genetics has begun, in which natural genetic variations for endocrine regulators have been characterized, almost exclusively in species of the cricket genus Gryllus. Artificial selection studies have documented that regulators of the juvenile hormone titer can rapidly evolve and exhibit levels of genetic variability similar to other physiological traits. Strong genetic correlations exist between some but not all regulators of the JH titer during the juvenile stage. No genetic correlation exists between regulators functioning in juvenile and adult stages, and thus, endocrine regulation can evolve independently in these stages. Genetic variation in the JH titer, the ecdysteroid titer, and JHE activity, in adult and juvenile stages, have been documented in genetic stocks of wing-polymorphic crickets; morph-specific differences in these endocrine traits are potentially responsible for genetically based differences in aspects of wing and flight muscle development, adult egg production, and adult dispersal. An unexpected morph-specific, genetic polymorphism for a circadian rhythm for the JH titer was observed in both the laboratory and field. Few comparable studies exist in non-Gryllus species, in which in vivo endocrine-genetic variation has been directly quantified using reliable analytical methods; many reported cases of endocrine variation in these species have been obtained using an inappropriate method and thus should be considered unsubstantiated. Obtaining basic information on the characteristics of natural genetic variation for endocrine regulators still remains one of the most important tasks of the fledgling subdiscipline of evolutionary endocrinology. Single gene endocrine mutants in Drosophila are promising candidates for investigating molecular-genetic variation in natural populations. Future studies should also focus on endocrine traits studied in the field and geographic

  20. The Time- and Age-dependent Effects of the Juvenile Hormone Analog Pesticide, Pyriproxyfen on Daphnia magna Reproduction

    PubMed Central

    Ginjupalli, Gautam K.; Baldwin, William S.

    2013-01-01

    Pyriproxyfen is an insecticidal juvenile hormone analog that perturbs insect and tick development. Pyriproxyfen also alters parthenogenic reproduction in non-target cladoceran species as it induces male production that can lead to a decrease in fecundity, a reduction in population density, and subsequent ecological effects. In this study, we investigate the impacts of pyriproxyfen on Daphnia magna reproduction using a series of male production screening assays. These assays demonstrate that pyriproxyfen increases male production in a concentration-dependent fashion with an EC50 of 156 pM (50.24 ng L-1); a concentration considered environmentally relevant. Furthermore, pyriproxyfen decreases overall fecundity at all ages tested (7, 14, 21-d old female parthenogenic daphnids). Juvenile (3-d old) and reproductively mature (10-d old) female daphnids were also exposed to 155 pM pyriproxyfen for 2 – 12 d and reproduction measured for 16 d to compare the effects of short-term and prolonged exposures, and determine the potential for recovery. Results indicate that longer pyriproxyfen exposures (8–12 d) extend male production and decrease reproduction; however, daphnids exposed for only 2–4 d recover and produce a relatively normal abundance of neonates. In addition, juvenile daphnids are also very sensitive to pyriproxyfen, but the primary effect on juvenile daphnids is reduced reproduction and protracted development not male production. Taken together, continued use of pyriproxyfen around water bodies needs due caution because of its potential adverse effects with significant developmental delays and male production compounded by prolonged exposure. PMID:23714148

  1. The time- and age-dependent effects of the juvenile hormone analog pesticide, pyriproxyfen on Daphnia magna reproduction.

    PubMed

    Ginjupalli, Gautam K; Baldwin, William S

    2013-08-01

    Pyriproxyfen is an insecticidal juvenile hormone analog that perturbs insect and tick development. Pyriproxyfen also alters parthenogenic reproduction in non-target cladoceran species as it induces male production that can lead to a decrease in fecundity, a reduction in population density, and subsequent ecological effects. In this study, we investigate the impacts of pyriproxyfen on Daphnia magna reproduction using a series of male production screening assays. These assays demonstrate that pyriproxyfen increases male production in a concentration-dependent fashion with an EC50 of 156pM (50.24ngL(-1)); a concentration considered environmentally relevant. Furthermore, pyriproxyfen decreases overall fecundity at all ages tested (7, 14, 21-d old female parthenogenic daphnids). Juvenile (3-d old) and reproductively mature (10-d old) female daphnids were also exposed to 155pM pyriproxyfen for 2-12d and reproduction measured for 16d to compare the effects of short-term and prolonged exposures, and determine the potential for recovery. Results indicate that longer pyriproxyfen exposures (8-12d) extend male production and decrease reproduction; however, daphnids exposed for only 2-4d recover and produce a relatively normal abundance of neonates. In addition, juvenile daphnids are also very sensitive to pyriproxyfen, but the primary effect on juvenile daphnids is reduced reproduction and protracted development not male production. Taken together, continued use of pyriproxyfen around water bodies needs due caution because of its potential adverse effects with significant developmental delays and male production compounded by prolonged exposure.

  2. Exposure of juvenile turbot (Scophthalmus maximus) to silver nanoparticles and 17α-ethinylestradiol mixtures: Implications for contaminant uptake and plasma steroid hormone levels.

    PubMed

    Farkas, Julia; Salaberria, Iurgi; Styrishave, Bjarne; Staňková, Radka; Ciesielski, Tomasz M; Olsen, Anders J; Posch, Wilfried; Flaten, Trond P; Krøkje, Åse; Salvenmoser, Willi; Jenssen, Bjørn M

    2017-01-01

    Combined exposure to engineered nanoparticles (ENPs) and anthropogenic contaminants can lead to changes in bioavailability, uptake and thus effects of both groups of contaminants. In this study we investigated effects of single and combined exposures of silver (Ag) nanoparticles (AgNPs) and the synthetic hormone 17α-ethinylestradiol (EE2) on tissue uptake of both contaminants in juvenile turbot (Scophthalmus maximus). Silver uptake and tissue distribution (gills, liver, kidney, stomach, muscle and bile) were analyzed following a 14-day, 2-h daily pulsed exposure to AgNPs (2 μg L(-1) and 200 μg L(-1)), Ag(+) (50 μg L(-1)), EE2 (50 ng L(-1)) and AgNP + EE2 (2 or 200 μg L(-1)+50 ng L(-1)). Effects of the exposures on plasma vitellogenin (Vtg) levels, EE2 and steroid hormone concentrations were investigated. The AgNP and AgNP + EE2 exposures resulted in similar Ag concentrations in the tissues, indicating that combined exposure did not influence Ag uptake in tissues. The highest Ag concentrations were found in gills. For the Ag(+) exposed fish, the highest Ag concentrations were measured in the liver. Our results show dissolution processes of AgNPs in seawater, indicating that the tissue concentrations of Ag may partly originate from ionic release. Plasma EE2 concentrations and Vtg induction were similar in fish exposed to the single contaminants and the mixed contaminants, indicating that the presence of AgNPs did not significantly alter EE2 uptake. Similarly, concentrations of most steroid hormones were not significantly altered due to exposures to the combined contaminants versus the single compound exposures. However, high concentrations of AgNPs in combination with EE2 caused a drop of estrone (E1) (female fish) and androstenedione (AN) (male and female fish) levels in plasma below quantification limits. Our results indicate that the interactive effects between AgNPs and EE2 are limited, with only high concentrations of AgNPs triggering

  3. Gender Differences in Cardiovascular Disease: Hormonal and Biochemical Influences

    PubMed Central

    Pérez-López, Faustino R.; Larrad-Mur, Luis; Kallen, Amanda; Chedraui, Peter; Taylor, Hugh S.

    2011-01-01

    Objective Atherosclerosis is a complex process characterized by an increase in vascular wall thickness owing to the accumulation of cells and extracellular matrix between the endothelium and the smooth muscle cell wall. There is evidence that females are at lower risk of developing cardiovascular disease (CVD) as compared to males. This has led to an interest in examining the contribution of genetic background and sex hormones to the development of CVD. The objective of this review is to provide an overview of factors, including those related to gender, that influence CVD. Methods Evidence analysis from PubMed and individual searches concerning biochemical and endocrine influences and gender differences, which affect the origin and development of CVD. Results Although still controversial, evidence suggests that hormones including estradiol and androgens are responsible for subtle cardiovascular changes long before the development of overt atherosclerosis. Conclusion Exposure to sex hormones throughout an individual's lifespan modulates many endocrine factors involved in atherosclerosis. PMID:20460551

  4. Effect of juvenile hormone analog, methoprene on H-fibroin regulation during the last instar larval development of Corcyra cephalonica.

    PubMed

    Chaitanya, R K; Sridevi, P; Senthilkumaran, B; Dutta Gupta, Aparna

    2013-01-15

    Juvenile hormone (JH) and 20-hydroxyecdysone (20E), co-ordinately orchestrate insect growth and development. The process of silk synthesis and secretion in lepidopteran insects is known to be under hormonal control. However, the role of JH in this process has not been demonstrated hitherto. The present study is aimed to elucidate the role of JH in H-fibroin regulation in Corcyra cephalonica, a serious lepidopteran pest. Reiterated amino acid stretches and the large molecular weight of H-fibroin render its cloning and characterization cumbersome. To address this, a commercially synthesized short amino acid peptide conjugated with a carrier protein was used to generate antibodies against the N-terminal region of H-fibroin. ELISA and immunoblot experiments demonstrated the sensitivity and specificity of antibody. Further, immunohistochemical analyses revealed the antibody's cross-reactivity with H-fibroins of C. cephalonica and Bombyx mori in the silk gland lumen. Quantitative RT-PCR and Western blot analysis demonstrated the tissue-specificity and developmental expression of H-fibroin. Hormonal studies revealed that JH alone does not alter the expression of H-fibroin. However, in the presence 20E, JH reverses the declined expression caused by 20E administration to normal levels. This study provides molecular evidence for the regulation of H-fibroin by the cumulative action of JH and 20E.

  5. Precocene-I inhibits juvenile hormone biosynthesis, ovarian activation, aggression and alters sterility signal production in bumble bee (Bombus terrestris) workers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Juvenile hormone (JH) is an important regulator of development and physiology in insects. While in many insect species, including bumble bees, JH function as gonadotropin in adults, in some highly eusocial insects its role has shifted to regulate social behavior including division of labor, dominanc...

  6. VARIATION IN GROWTH, LIPID CLASS AND FATTY ACID COMPOSITION OF THE MUD CRAB, RHITHROPANOPEUS HARRISII (GOULD) DURING LARVAL DEVELOPMENT FOLLOWING EXPOSURE TO AN INSECT JUVENILE HORMONE ANALOG (FENOXYCARB)

    EPA Science Inventory

    This study examines the effects of fenoxycarb?, an insect juvenile hormone analog, on larval growth, and lipid class and fatty acid composition in first crabs of the mud crab Rhithropanopeus harrisii reared through total larval development in nominal water concentrations from 1 ...

  7. SEX DIFFERENCES AND REPRODUCTIVE HORMONE INFLUENCES ON HUMAN ODOR PERCEPTION

    PubMed Central

    Doty, Richard L.; Cameron, E. Leslie

    2009-01-01

    The question of whether men and women differ in their ability to smell has been the topic of scientific investigation for over a hundred years. Although conflicting findings abound, most studies suggest that, for at least some odorants, women outperform men on tests of odor detection, identification, discrimination, and memory. Most functional imaging and electrophysiological studies similarly imply that, when sex differences are present, they favor women. In this review we examine what is known about sex-related alterations in human smell function, including influences of the menstrual cycle, pregnancy, gonadectomy, and hormone replacement therapy on a range of olfactory measures. We conclude that the relationship between reproductive hormones and human olfactory function is complex and that simple associations between circulating levels of gonadal hormones and measures of olfactory function are rarely present. PMID:19272398

  8. [How corticoids, growth hormone and oestrogens influence lipids and atherosclerosis].

    PubMed

    Marek, J; Hána, V; Krsek, M

    2007-04-01

    The hormones with a strong influence on the lipid spectrum and the development of atherosclerosis include cortisol, growth hormone and oestrogens. Cortisol accelerates atherosclerosis both through dyslipidemia and through an increase in visceral fat, hypertension, increased insulin resistance and the development of reduced glucose tolerance which may result in diabetes mellitus. Even when a cortisol excess disappears, as is the case of patients cured of Cushing syndrome, arterial walls remain permanently vulnerable to the atherosclerotic process. In conditions involving a lack of growth hormone, dyslipidemia develops and increases the burden on the cardiovascular system if not treated in a timely manner by the substitution of growth hormone. Oestrogens have a double effect: they have an anti-atherogenic effect on artery walls that are not yet damaged by an atherosclerotic process, but where atherosclerosis has already developed they have a prothrombotic effect and destabilise the atheromatous plaques. If oestrogen is to be used as protection against the onset of atherogenesis, it is necessary to start in a period when the atherosclerotic process has not yet begun to damage the woman's arterial walls and it is best to use natural hormones (estradiol) and to prevent endometriosis it should be combined with crystalline progesterone applied locally--inravaginally. Oestrogens should be given in small doses, preferably parenterally. Even this will not prevent genetic oestrogen effects though.

  9. Juvenile hormone stimulated tyrosine kinase-mediated protein phosphorylation in the CNS of the silk worm, Bombyx mori.

    PubMed

    Arif, A; Shanavas, A; Murthy, Ch R K; Dutta-Gupta, Aparna

    2002-07-01

    In vitro studies with the larval CNS of the silkworm, Bombyx mori revealed the phosphorylation of a 48-kDa protein, which was not dependent on cyclic nucleotides. Studies also revealed modest phosphorylation of this protein by a calcium-dependent but calmodulin-independent mechanism. However, phosphorylation of this protein was greatly enhanced in the presence of juvenile hormone (JH) I by a calcium-independent mechanism. This stimulatory effect of JH was seen in both homogenates as well as in intact CNS of Bombyx. Immunoblotting studies revealed the cross-reaction of this 48-kDa protein with phosphotyrosine monoclonal antibody and the phosphorylation of this protein was inhibited by genistein. This study suggests that the 48-kDa protein is a substrate for tyrosine kinase. The phosphorylation of this protein was also observed in other larval tissues such as salivary gland, fat body, and epidermis of Bombyx.

  10. Tissue localization and regulation by juvenile hormone of human allergen Bla g 4 from the German cockroach, Blattella germanica (L.).

    PubMed

    Fan, Y; Gore, J C; Redding, K O; Vailes, L D; Chapman, M D; Schal, C

    2005-01-01

    The German cockroach, Blattella germanica (L.), produces several potent protein aeroallergens, including Bla g 4, a approximately 20 kDa lipocalin. RT-PCR, Northern analyses and in situ hybridization showed that Bla g 4 is expressed only in the adult male reproductive system. Western blotting and ELISA with rBla g 4 antiserum detected immunoreactivity in the utricles and the conglobate gland, but not in other tissues of the male reproductive system. The Bla g 4 protein content of males increased from adult emergence to day 14, but during copulation Bla g 4 was depleted in the male and transferred to the female within the spermatophore. Topical application of juvenile hormone III stimulated Bla g 4 production by both conglobate gland and utricles.

  11. [Role of DopR in the molecular mechanism of the dopamine control of juvenile hormone metabolism in female Drosophila].

    PubMed

    Karpova, E K; Bogomolova, E V; Romonova, I V; Gruntenko, N E; Raushenbakh, I Iu

    2012-08-01

    The effect of a decreased availability of the D1-like dopamine receptor (DopR) in Drosophila (caused by DopR antagonist added into food) on the juvenile hormone (JH) synthesis rate in young female D. melanogaster has been studied. The JH degradation rate and the alkaline phosphatase (ALP) and tyrosine decarboxylase (TDC) activities were used as indicators of the JH synthesis rate. Treatment of the flies with butaclamol, a specific DopR antagonist, has been demonstrated to increase the JH degradation rate, and the stress reactivity of the system of JH metabolism and decrease the ALP activity and stress reactivity, and increase the TDC activity and stress reactivity. As shown earlier, all this indicates a decrease in the JH synthesis rate in young female drosophila with a decreased DopR availability. It is concluded that the activating effect of dopamine on JH synthesis in Drosophila is mediated by D1-like receptors.

  12. Lipophorin of female Blattella germanica (L.): characterization and relation to hemolymph titers of juvenile hormone and hydrocarbons.

    PubMed

    Sevala, V; Shu, S; Ramaswamy, S B.; Schal, C

    1999-05-01

    High density lipophorin (HDLp) from the hemolymph of the German cockroach, Blattella germanica (L.) (Family Blattellidae), has an apparent molecular weight of 670kDa, with an isoelectric point of 7.0 and a density of 1.109g/ml. It is composed of two subunits, apolipoprotein-I (212kDa) and apolipoprotein-II (80kDa), and consists of 51.4% lipid, 46.2% protein and 2.4% carbohydrate. Hydrocarbons constitute 42.2% of the total lipids which also contain diacylglycerol, cholesterol and phospholipid. Lipophorin is rich in the amino acids glutamic acid, aspartic acid, lysine, valine, and leucine. Specificity of a polyclonal antibody was demonstrated by Western blotting and Ouchterlony immunodiffusion: the antiserum recognized native HDLp and apolipoprotein-I, but not apolipoprotein-II, purified vitellin, or other hemolymph proteins. It also recognized a protein in the hemolymph of Supella longipalpa (Blattellidae) but did not cross-react with hemolymph proteins from Periplaneta americana (Blattidae) or Diploptera punctata (Blaberidae). An enzyme-linked immunosorbent assay was developed to measure the HDLp titer in the hemolymph of adult females. The titer of HDLp, a juvenile hormone binding protein, exhibited no clear relationship to the changing titer of juvenile hormone in hemolymph. The hemolymph titer of hydrocarbon, which is also carried by HDLp, showed some functional relation to the concentration of HDLp in the hemolymph. Because it concurrently serves multiple functions in insect development and reproduction, lipophorin titer might covary with the titers of lipid ligands that occur at high concentrations and require extensive shuttling through the hemolymph.

  13. Juvenile hormone prevents 20-hydroxyecdysone-induced metamorphosis by regulating the phosphorylation of a newly identified broad protein.

    PubMed

    Cai, Mei-Juan; Liu, Wen; Pei, Xu-Yang; Li, Xiang-Ru; He, Hong-Juan; Wang, Jin-Xing; Zhao, Xiao-Fan

    2014-09-19

    The steroid hormone 20-hydroxyecdysone (20E) initiates insect molting and metamorphosis. By contrast, juvenile hormone (JH) prevents metamorphosis. However, the mechanism by which JH inhibits metamorphosis remains unclear. In this study, we propose that JH induces the phosphorylation of Broad isoform Z7 (BrZ7), a newly identified protein, to inhibit 20E-mediated metamorphosis in the lepidopteran insect Helicoverpa armigera. The knockdown of BrZ7 in larvae inhibited metamorphosis by repressing the expression of the 20E response gene. BrZ7 was weakly expressed and phosphorylated during larval growth but highly expressed and non-phosphorylated during metamorphosis. JH regulated the rapid phosphorylation of BrZ7 via a G-protein-coupled receptor-, phospholipase C-, and protein kinase C-triggered pathway. The phosphorylated BrZ7 bound to the 5'-regulatory region of calponin to regulate its expression in the JH pathway. Exogenous JH induced BrZ7 phosphorylation to prevent metamorphosis by suppressing 20E-related gene transcription. JH promoted non-phosphorylated calponin interacting with ultraspiracle protein to activate the JH pathway and antagonize the 20E pathway. This study reveals one of the possible mechanisms by which JH counteracts 20E-regulated metamorphosis by inducing the phosphorylation of BrZ7.

  14. A cumulative feeding threshold required for vitellogenesis can be obviated with juvenile hormone treatment in lubber grasshoppers.

    PubMed

    Fronstin, R B; Hatle, J D

    2008-01-01

    Developmental thresholds can ensure that an adequate condition has been attained to proceed through major transitions (e.g. initiation of reproduction, metamorphosis). Nutrition is critical to attaining most thresholds, because it is needed for both growth and storage. Attaining a threshold typically stimulates the release of hormones that commit the animal to the developmental transition, yet the relationships between the nutrition needed for developmental thresholds and these endocrine signals are poorly understood. Lubber grasshoppers require a cumulative feeding threshold to initiate vitellogenesis and potentially commit to oviposition. We tested the relative roles of the nutritional threshold and the major gonadotropin (juvenile hormone; JH) in initiating vitellogenesis and committing to oviposition. The source of JH was removed from all females, and then JH analog was applied after different amounts of feeding. Threshold feeding was not required to initiate vitellogenesis, suggesting that sub-threshold grasshoppers are competent to respond to JH. Further, sub-threshold grasshoppers went on to oviposit earlier than supra-threshold grasshoppers treated with JH at the same time. Hence, threshold feeding is required only to cause the production and release of JH. At the same time, we also found that individuals that were restored with JH late in life tended to favor current reproduction, at the expense of future reproduction. Both time to oviposition and vitellogenin profiles were consistent with this developmental allocation. Taken together, our results suggest that lubber grasshoppers adjust reproductive tactics primarily in response to nutrition (which only serves to release JH) and secondarily in response to age.

  15. Pleiotropic effects of juvenile hormone in ant queens and the escape from the reproduction–immunocompetence trade-off

    PubMed Central

    Pamminger, Tobias; Treanor, David; Hughes, William O. H.

    2016-01-01

    The ubiquitous trade-off between survival and costly reproduction is one of the most fundamental constraints governing life-history evolution. In numerous animals, gonadotropic hormones antagonistically suppressing immunocompetence cause this trade-off. The queens of many social insects defy the reproduction–survival trade-off, achieving both an extraordinarily long life and high reproductive output, but how they achieve this is unknown. Here we show experimentally, by integrating quantification of gene expression, physiology and behaviour, that the long-lived queens of the ant Lasius niger have escaped the reproduction–immunocompetence trade-off by decoupling the effects of a key endocrine regulator of fertility and immunocompetence in solitary insects, juvenile hormone (JH). This modification of the regulatory architecture enables queens to sustain a high reproductive output without elevated JH titres and suppressed immunocompetence, providing an escape from the reproduction–immunocompetence trade-off that may contribute to the extraordinary lifespan of many social insect queens. PMID:26763704

  16. Influence of hormones and hormone antagonists on sexual differentiation of the brain.

    PubMed

    Döhler, K D

    1998-01-01

    In summary, a number of studies have shown that not only estrogenic and androgenic steroids and their antagonists influence sexual differentiation of the mammalian brain but also drugs which stimulate or inhibit the adrenergic, the serotoninergic, or the cholinergic system in the developing brain. The present knowledge on the possible participation of neurotransmitter systems in sexual differentiation of the brain and their mode of interaction in this process perinatally with gonadal steroids is still rather limited. Sexual differentiation of the central nervous system is a complex integrated process, which relies on proper chronological and quantitative interactions of various endocrine and neuroendocrine mediators. Any disturbance of this delicate endogenous hormonal balance during ontogenetic development, e.g. by means of environmental influences, can result in permanent manifestation of anatomic and functional sexual deviations. A large number of man-made chemicals that have been released into the environment have the potential to disrupt the endocrine system of animals and humans. They do so because they mimick the effects of natural hormones or neurotransmitters by recognizing their binding sites, or they antagonize the effects of endogenous hormones or neurotransmitters by blocking their interaction with their physiological binding sites. Interaction of environmental endocrine disruptors with animals or humans during ontogeny may have deleterious effects on the differentiation of reproductive structures and functions, rendering the individuals in question permanently incapable to reproduce and, thus, endangering survival of the species.

  17. Farnesol-Like Endogenous Sesquiterpenoids in Vertebrates: The Probable but Overlooked Functional “Inbrome” Anti-Aging Counterpart of Juvenile Hormone of Insects?

    PubMed Central

    De Loof, Arnold; Marchal, Elisabeth; Rivera-Perez, Crisalejandra; Noriega, Fernando G.; Schoofs, Liliane

    2014-01-01

    Literature on the question whether the juvenile stage of vertebrates is hormonally regulated is scarce. It seems to be intuitively assumed that this stage of development is automated, and does not require any specific hormone(s). Such reasoning mimics the state of affairs in insects until it was shown that surgical removal of a tiny pair of glands in the head, the corpora allata, ended larval life and initiated metamorphosis. Decades later, the responsible hormone was found and named “juvenile hormone” (JH) because when present, it makes a larva molt into another larval stage. JH is a simple ester of farnesol, a sesquiterpenoid present in all eukaryotes. Whereas vertebrates do not have an anatomical counterpart of the corpora allata, their tissues do contain farnesol-like sesquiterpenoids (FLS). Some display typical JH activity when tested in appropriate insect bioassays. Some FLS are intermediates in the biosynthetic pathway of cholesterol, a compound that insects and nematodes (=Ecdysozoa) cannot synthesize by themselves. They ingest it as a vitamin. Until a recent (2014) reexamination of the basic principle underlying insect metamorphosis, it had been completely overlooked that the Ca2+-pump (SERCA) blocker thapsigargin is a sesquiterpenoid that mimics the absence of JH in inducing apoptosis. In our opinion, being in the juvenile state is primarily controlled by endogenous FLS that participate in controlling the activity of Ca2+-ATPases in the sarco(endo)plasmic reticulum (SERCAs), not only in insects but in all eukaryotes. Understanding the control mechanisms of being in the juvenile state may boost research not only in developmental biology in general, but also in diseases that develop after the juvenile stage, e.g., Alzheimer’s disease. It may also help to better understand some of the causes of obesity, a syndrome that holometabolous last larval insects severely suffer from, and for which they found a very drastic but efficient solution, namely

  18. The fate of follicles after a blood meal is dependent on previtellogenic nutrition and juvenile hormone in Aedes aegypti.

    PubMed

    Clifton, Mark E; Noriega, Fernando G

    2012-07-01

    Juvenile hormone (JH) mediates the relationship between fecundity and nutrition during the gonotrophic cycle of the mosquito in three ways: (1) by regulating initial previtellogenic development, (2) by mediating previtellogenic resorption of follicles and (3) by altering intrinsic previtellogenic follicle "quality", physiology, and competitiveness thereby predetermining the fate of follicles after a blood meal. To support a role for JH in mediating the response of ovarian follicles after a blood meal, we explored three main questions: (1) Do changes in nutrition during the previtellogenic resting stage lead to relevant biochemical and molecular changes in the previtellogenic ovary? (2) Do hormonal manipulations during the previtellogenic resting stage lead to the same biochemical and molecular changes? (3) Does nutrition and hormones during the previtellogenic resting stage affect vitellogenic resorption and reproductive output? We examined the accumulation of neutral lipids in the previtellogenic ovary as well as the previtellogenic expression of genes integral to endocytosis and oocyte development such as the: vitellogenin receptor (AaVgR), lipophorin receptor (AaLpRov), heavy-chain clathrin (AaCHC), and ribosomal protein L32 (rpL32) under various previtellogenic nutritional and hormonal conditions. mRNA abundance and neutral lipid content increased within the previtellogenic ovary as previtellogenic mosquitoes were offered increasing sucrose concentrations. Methoprene application mimicked the effect of offering the highest sucrose concentrations on mRNA abundance and lipid accumulation in the previtellogenic ovary. These same nutritional and hormonal manipulations altered the extent of vitellogenic resorption. Mosquitoes offered 20% sucrose during the previtellogenic resting stage had nearly 3 times less vitellogenic resorption than mosquitoes offered 3% sucrose despite taking smaller blood meals and developed ∼10% more eggs during the first gonotrophic cycle

  19. Influence of food availability on the spatial distribution of juvenile fish within soft sediment nursery habitats

    NASA Astrophysics Data System (ADS)

    Tableau, A.; Brind'Amour, A.; Woillez, M.; Le Bris, H.

    2016-05-01

    Soft sediments in coastal shallow waters constitute nursery habitats for juveniles of several flatfishes. The quality of a nursery is defined by its capacity to optimize the growth and the survival of juvenile fish. The influence of biotic factors, such as food availability, is poorly studied at the scale of a nursery ground. Whether food availability limits juvenile survival is still uncertain. A spatial approach is used to understand the influence of food availability on the distribution of juvenile fish of various benthic and demersal species in the Bay of Vilaine (France), a productive nursery ground. We quantified the spatial overlap between benthic macro-invertebrates and their predators (juvenile fish) to assess if the latter were spatially covering the most productive areas of the Bay. Three scenarios describing the shapes of the predator-prey spatial relationship were tested to quantify the strength of the relationship and consequently the importance of food availability in determining fish distribution. Our results underline that both food availability and fish densities vary greatly over the nursery ground. When considering small organisational levels (e.g., a single fish species), the predator-prey spatial relationship was not clear, likely because of additional environmental effects not identified here; but at larger organisational level (the whole juvenile fish community), a strong overlap between the fish predators and their prey was identified. The evidence that fish concentrate in sectors with high food availability suggests that either food is the limiting factor in that nursery or/and fish display behavioural responses by optimising their energetic expenditures associated with foraging. Further investigations are needed to test the two hypotheses and to assess the impact of benthic and demersal juvenile fish in the food web of coastal nurseries.

  20. Factors Influencing Emergence of Juveniles from Cysts of Heterodera zeae

    PubMed Central

    Hashmi, Sarwar; Krusberg, Lorin R.

    1995-01-01

    Several factors were studied to determine their effects on hatch and emergence of second-stage juveniles (J2) from cysts of Heterodera zeae. The optimum temperature for emergence of J2 from cysts of H. zeae was 30 C. No juveniles emerged from cysts at 10 or 40 C. Immersion of cysts in 4 mM zinc chloride solution stimulated 10% greater emergence of J2 than occurred in tap water controls during 28 days. Fresh corn rhizosphere leachates from 25-day and older plants growing in sand or sandy field soil stimulated 22-24% greater emergence of J2 from cysts than occurred in tap water after 28 days. Rhizosphere leachates stored for 30 days at 4 C and leachates of sand, sandy field soil, and silty field soil inhibited emergence of J2 from cysts by 7-12% compared to tap water. Rhizosphere leachates from corn plants aged 20, 30, 40, 50, or 60 days growing in sandy field soil stimulated emergence of J2 from cysts. Similar numbers of J2 emerged from cysts regardless of whether the source of cysts was field microplot cultures, greenhouse cultures, or growth chamber cultures. Fertilizing growth chamber cultures of H. zeae on corn plants resulted in a doubling of the numbers of cysts produced in the cultures, and those cysts yielded 2-3 times as many emerged J2 in hatching tests compared to cysts from similar unfertilized cultures. PMID:19277300

  1. Ecdysteroids, juvenile hormone and insect neuropeptides: Recent successes and remaining major challenges.

    PubMed

    De Loof, Arnold

    2008-01-01

    In the recent decade, tremendous progress has been realized in insect endocrinology as the result of the application of a variety of advanced methods in neuropeptidome- and receptor research. Hormones of which the existence had been shown by bioassays four decades ago, e.g. bursicon (a member of the glycoprotein hormone family) and pupariation factor (Neb-pyrokinin 2, a myotropin), could be identified, along with their respective receptors. In control of diurnal rhythms, clock genes got company from the neuropeptide Pigment Dispersing Factor (PDF), of which the receptor could also be identified. The discovery of Inka cells and their function in metamorphosis was a true hallmark. Analysis of the genomes of Caenorhabditis elegans, Drosophila melanogaster and Apis mellifera yielded about 75, 100 and 200 genes coding for putative signaling peptides, respectively, corresponding to approximately 57, 100 and 100 peptides of which the expression could already be proven by means of mass spectrometry. The comparative approach invertebrates-vertebrates recently yielded indications for the existence of counterparts in insects for prolactin, atrial natriuretic hormone and Growth Hormone Releasing Hormone (GRH). Substantial progress has been realized in identifying the Halloween genes, a membrane receptor(s) for ecdysteroids, a nuclear receptor for methylfarnesoate, and dozens of GPCRs for insect neuropeptides. The major remaining challenges concern the making match numerous orphan GPCRs with orphan peptidic ligands, and elucidating their functions. Furthermore, the endocrine control of growth, feeding-digestion, and of sexual differentiation, in particular of males, is still poorly understood. The finding that the prothoracic glands produce an autocrine factor with growth factor-like properties and secrete proteins necessitates a reevaluation of their role in development.

  2. A whole genome screening and RNA interference identify a juvenile hormone esterase-like gene of the diamondback moth, Plutella xylostella.

    PubMed

    Gu, Xiaojun; Kumar, Sunil; Kim, Eunjin; Kim, Yonggyun

    2015-09-01

    Juvenile hormone (JH) plays a crucial role in preventing precocious metamorphosis and stimulating reproduction. Thus, its hemolymph titer should be under a tight control. As a negative controller, juvenile hormone esterase (JHE) performs a rapid breakdown of residual JH in the hemolymph during last instar to induce a larval-to-pupal metamorphosis. A whole genome of the diamondback moth (DBM), Plutella xylostella, has been annotated and proposed 11 JHE candidates. Sequence analysis using conserved motifs commonly found in other JHEs proposed a putative JHE (Px004817). Px004817 (64.61 kDa, pI=5.28) exhibited a characteristic JHE expression pattern by showing high peak at the early last instar, at which JHE enzyme activity was also at a maximal level. RNA interference of Px004817 reduced JHE activity and interrupted pupal development with a significant increase of larval period. This study identifies Px004817 as a JHE-like gene of P. xylostella.

  3. Influences of neighborhood context, individual history and parenting behavior on recidivism among juvenile offenders.

    PubMed

    Grunwald, Heidi E; Lockwood, Brian; Harris, Philip W; Mennis, Jeremy

    2010-09-01

    This study examined the effects of neighborhood context on juvenile recidivism to determine if neighborhoods influence the likelihood of reoffending. Although a large body of literature exists regarding the impact of environmental factors on delinquency, very little is known about the effects of these factors on juvenile recidivism. The sample analyzed includes 7,061 delinquent male juveniles committed to community-based programs in Philadelphia, of which 74% are Black, 13% Hispanic, and 11% White. Since sample youths were nested in neighborhoods, a hierarchical generalized linear model was employed to predict recidivism across three general categories of recidivism offenses: drug, violent, and property. Results indicate that predictors vary across the types of offenses and that drug offending differs from property and violent offending. Neighborhood-level factors were found to influence drug offense recidivism, but were not significant predictors of violent offenses, property offenses, or an aggregated recidivism measure, despite contrary expectations. Implications stemming from the finding that neighborhood context influences only juvenile drug recidivism are discussed.

  4. Examining the Influence of Ethnic/Racial Socialization on Aggressive Behaviors Among Juvenile Offenders.

    PubMed

    Zapolski, Tamika C B; Garcia, Crystal A; Jarjoura, G Roger; Lau, Katherine S L; Aalsma, Matthew C

    2016-01-01

    Risk assessment instruments are commonly used within the juvenile justice system to estimate a juvenile's likelihood of reoffending or engaging in aggressive or violent behavior. Although such instruments assess a broad range of factors, the influence of culture is often excluded. The current study examines the unique effect of ethnic/racial socialization on recent aggressive behaviors above and beyond three well-established risk and protective factors: delinquency history, moral disengagement, and social support. Participants were 95 juveniles who were either on probation or in detention centers in three Midwestern counties and who completed structured surveys related to personal experiences within and outside of the juvenile justice system. The findings provided partial support for our hypotheses: Consistent with previous findings, delinquency history and moral disengagement were significant predictors of recent aggressive behavior. Furthermore, when ethnic/racial socialization was added to the model, promotion of mistrust provided additional predictive validity for aggressive behavior above and beyond the other factors assessed. Based on these findings, the inclusion of education on culture may prove to be an important supplement to established intervention tools for juvenile offenders.

  5. Examining the Influence of Ethnic/Racial Socialization on Aggressive Behaviors Among Juvenile Offenders

    PubMed Central

    Zapolski, Tamika C. B.; Garcia, Crystal A.; Jarjoura, G. Roger; Lau, Katherine S. L.; Aalsma, Matthew C.

    2016-01-01

    Risk assessment instruments are commonly used within the juvenile justice system to estimate a juvenile's likelihood of reoffending or engaging in aggressive or violent behavior. Although such instruments assess a broad range of factors, the influence of culture is often excluded. The current study examines the unique effect of ethnic/racial socialization on recent aggressive behaviors above and beyond three well-established risk and protective factors: delinquency history, moral disengagement, and social support. Participants were 95 juveniles who were either on probation or in detention centers in three Midwestern counties and who completed structured surveys related to personal experiences within and outside of the juvenile justice system. The findings provided partial support for our hypotheses: Consistent with previous findings, delinquency history and moral disengagement were significant predictors of recent aggressive behavior. Furthermore, when ethnic/racial socialization was added to the model, promotion of mistrust provided additional predictive validity for aggressive behavior above and beyond the other factors assessed. Based on these findings, the inclusion of education on culture may prove to be an important supplement to established intervention tools for juvenile offenders. PMID:27453798

  6. Brain sex differences and hormone influences: a moving experience?

    PubMed

    Tobet, S; Knoll, J G; Hartshorn, C; Aurand, E; Stratton, M; Kumar, P; Searcy, B; McClellan, K

    2009-03-01

    Sex differences in the nervous system come in many forms. Although a majority of sexually dimorphic characteristics in the brain have been described in older animals, mechanisms that determine sexually differentiated brain characteristics often operate during critical perinatal periods. Both genetic and hormonal factors likely contribute to physiological mechanisms in development to generate the ontogeny of sexual dimorphisms in brain. Relevant mechanisms may include neurogenesis, cell migration, cell differentiation, cell death, axon guidance and synaptogenesis. On a molecular level, there are several ways to categorize factors that drive brain development. These range from the actions of transcription factors in cell nuclei that regulate the expression of genes that control cell development and differentiation, to effector molecules that directly contribute to signalling from one cell to another. In addition, several peptides or proteins in these and other categories might be referred to as 'biomarkers' of sexual differentiation with undetermined functions in development or adulthood. Although a majority of sex differences are revealed as a direct consequence of hormone actions, some may only be revealed after genetic or environmental disruption. Sex differences in cell positions in the developing hypothalamus, and steroid hormone influences on cell movements in vitro, suggest that cell migration may be one target for early molecular actions that impact brain development and sexual differentiation.

  7. Insect juvenile hormone mimics against the short-nosed cattle louse, Haematopinus eurysternus Denny (Anoplura), and their effect on warbles of Hypoderma sp. Latr. (Diptera:Oestridae).

    PubMed

    Meleney, W P; Roberts, I H

    1975-10-01

    Insect juvenile hormone mimics (IJH) at 0.1 and 0.01% were used as sprays for control of the short-nosed cattle louse, Haematopinus eurysternus Denny, on 11 heavily infested Hereford cows. A significant reduction of lice occurred although eradication was achieved in only one case. Severe reactions, apparently associated with the death or failure of complete development of cattle grub larvae, Hypoderma sp. Latr., were seen in the IJH-treated cows.

  8. Control of larval-pupal-adult molt in the moth Sesamia nonagrioides by juvenile hormone and ecdysteroids.

    PubMed

    Pérez-Hedo, Meritxell; Goodman, Walter G; Schafellner, Christa; Martini, Antonio; Sehnal, Frantisek; Eizaguirre, Matilde

    2011-05-01

    Sesamia nonagrioides (Lepidoptera: Noctuidae) larvae reared under long day (LD; 16L:8D) conditions pupate after 5 or 6 larval instars, whereas under short day (SD; 12L:12D) conditions they undergo up to 12 additional molts before pupating. This extended period of repeated molting is maintained by high levels of juvenile hormone (JH). Previous work demonstrated that both LD and SD larvae decapitated in the 6th instar pupate but further development is halted. By contrast, about one-third of SD larvae from which only the brain has been removed, undergo first a larval molt, then pupate and subsequently developed to the adult stage. Debrained LD larvae molt to larvae exceptionally but regularly pupate and produce adults. Implanted brains may induce several larval molts in debrained recipient larvae irrespectively of the photoperiodic conditions. The results of present work demonstrate that the prothoracic glands (PGs) and the corpora allata (CA) of debrained larvae continue to produce ecdysteroids and JHs, respectively. PGs are active also in the decapitated larvae that lack JH, consistent with the paradigm that CA, which are absent in the decapitated larvae, are the only source of this hormone. Completion of the pupal-adult transformation in both LD and SD debrained insects demonstrates that brain is not crucial for the development of S. nonagrioides but is required for diapause maintenance. Application of JH to headless pupae induces molting, presumably by activating their PGs. It is likely that JH plays this role also in the induction of pupal-adult transformation in debrained insects. Application of the ecdysteroid agonist RH 2485 (methoxyfenozide) to headless pupae also elicits molting: newly secreted cuticle is in some cases thin and indifferent, in other cases it bears distinct pupal or adult features.

  9. Juvenile hormone titers, ovarian status and epicuticular hydrocarbons in gynes and workers of the paper wasp Belonogaster longitarsus.

    PubMed

    Kelstrup, Hans C; Hartfelder, Klaus; Esterhuizen, Nanike; Wossler, Theresa C

    2017-04-01

    The prevailing paradigm for social wasp endocrinology is that of juvenile hormone (JH) functioning pleiotropically in potential and actual queens, where it fuels dominance behaviors, stimulates ovarian growth and/or affects the production of status-linked cuticular compounds. In colonies with annual cycles (e.g., temperate-zone species), female adults produced at the end of the summer (called gynes) are physiologically primed to hibernate. Despite the absence of egg-laying in the pre-overwintering phase, gynes engage in dominance interactions that may affect reproductive potential following hibernation. JH levels have long been inferred to be low in gynes but this has never been tested. In what is the first study to measure JH in gyne-containing colonies of a temperate paper wasp, and the first to incorporate hormone assays in Belonogaster, our results show that the JH titer positively correlates with gyne-specific traits (including oocyte length and a low frequency of foraging trips) in B. longitarsus, a South African paper wasp. Measures of dominance correlated with oocyte length, but not all dominant females possessed activated ovaries. The cuticular hydrocarbon profiles of gynes and workers were distinct, with oocyte length and JH titer showing a positive association with longer-chain methyl-branched alkanes. Nonetheless, evidence for a role of JH in dominance was inconclusive. Finally, the range of JH titers among gynes, and the positive association of JH titers with ovarian status and prospective fertility signals, makes it unlikely that the gyne phenotype is maintained by low JH levels.

  10. Function of Phe-259 and Thr-314 within the Substrate Binding Pocket of the Juvenile Hormone Esterase of Manduca sexta†

    PubMed Central

    Kamita, Shizuo G.; Wogulis, Mark D.; Law, Christopher S.; Morisseau, Christophe; Tanaka, Hiromasa; Huang, Huazhang; Wilson, David K.; Hammock, Bruce D.

    2013-01-01

    Juvenile hormone (JH) is a key insect developmental hormone that is found at low nanomolar levels in larval insects. The methyl ester of JH is hydrolyzed in many insects by an esterase that shows high specificity for JH. We have previously determined a crystal structure of the JH esterase (JHE) of the tobacco hornworm Manduca sexta (MsJHE) [Wogulis, M., Wheelock, C. E., Kamita, S. G., Hinton, A. C., Whetstone, P. A., Hammock, B. D., and Wilson, D. K. (2006) Biochemistry 45, 4045-4057]. Our molecular modeling indicates that JH fits very tightly within the substrate binding pocket of MsJHE. This tight fit places two non-catalytic amino acid residues, Phe-259 and Thr-314, within the appropriate distance and geometry to potentially interact with the α,β-unsaturated ester and epoxide, respectively, of JH. These residues are highly conserved in numerous biologically active JHEs. Kinetic analyses of mutants of Phe-259 or Thr-314 indicate that these residues contribute to the low KM that MsJHE shows for JH. This low KM, however, comes at the cost of reduced substrate turnover. Neither nucleophilic attack of the resonance stabilized ester by the catalytic serine nor the availability of a water molecule for attack of the acyl-enzyme intermediate appear to be a rate-determining step in the hydrolysis of JH by MsJHE. We hypothesize that the release of the JH acid metabolite from the substrate binding pocket limits the catalytic cycle. Our findings also demonstrate that chemical bond strength does not necessarily correlate with how reactive the bond will be to metabolism. PMID:20307057

  11. Potential influence of hormones in the development of slipped capital femoral epiphysis: a preliminary study.

    PubMed

    Papavasiliou, Kyriakos A; Kirkos, John M; Kapetanos, George A; Pournaras, John

    2007-01-01

    The potential influence of hormonal imbalance on the development of slipped capital femoral epiphysis was assessed through a prospective clinical study. The serum levels of T3, T4, thyroid-stimulating hormone, testosterone, estradiol, dehydroepiandrosterone-sulfate, follicle-stimulating hormone, luteinizing hormone, human growth hormone, adrenal cortex hormone and cortisol were evaluated in seven boys and seven girls. Forty-three out of 154 hormonal determinations (27.9%) were abnormal. The results showed increased incidence of pathological values mainly in the levels of follicle-stimulating-hormone, luteinizing-hormone and testosterone. No patient had clinical findings of endocrinopathy. A (possibly) temporary hormonal disorder may play a potentially significant role in the development of slipped capital femoral epiphysis.

  12. The insulin/TOR signal transduction pathway is involved in the nutritional regulation of juvenile hormone synthesis in Aedes aegypti.

    PubMed

    Pérez-Hedo, Meritxell; Rivera-Perez, Crisalejandra; Noriega, Fernando G

    2013-06-01

    Juvenile hormone (JH) levels must be modulated to permit the normal progress of development and reproductive maturation in mosquitoes. JH is part of a transduction system that assesses nutritional information and controls reproduction in mosquitoes. Adult female Aedes aegypti show nutritionally-dependent dynamic changes in corpora allata (CA) JH biosynthetic activities. A coordinated expression of most JH biosynthetic enzymes has been described in female pupae and adult mosquitoes; increases or decreases in transcript levels for all the enzymes were concurrent with increases or decreases in JH synthesis; suggesting that transcriptional changes are at least partially responsible for the dynamic changes of JH biosynthesis. The goal of the present study is to identify signaling network components responsible for the nutritional-dependent changes of JH synthesis in the CA of mosquitoes. The insulin/TOR signaling network plays a central role in the transduction of nutritional signals that regulate cell growth and metabolism in insects. These pathways have also been suggested as a link between nutritional signals and JH synthesis regulation in the CA of cockroaches and flies. We used a combination of in vitro studies and in vivo genetic knockdown experiments to explore nutritional signaling pathways in the CA. Our results suggest that the insulin/TOR pathway plays a role in the transduction of the nutritional information that regulates JH synthesis in mosquitoes. Transcriptional regulation of the genes encoding JH biosynthetic enzymes is at least partially responsible for these nutritionally modulated changes of JH biosynthesis.

  13. Allatostatin-C reversibly blocks the transport of citrate out of the mitochondria and inhibits juvenile hormone synthesis in mosquitoes.

    PubMed

    Nouzova, Marcela; Rivera-Perez, Crisalejandra; Noriega, Fernando G

    2015-02-01

    Aedes aegypti allatostatin-C (AeaAST-C or PISCF-AST) is a strong and fast reversible inhibitor of juvenile hormone III (JH III) synthesis by the corpora allata (CA) of mosquitoes; however, its mechanism of action remains poorly understood. AeaAST-C showed no inhibitory activity in the presence of any of the intermediate precursors of JH III indicating that the AeaAST-C target is located before the entry of acetyl-CoA in the pathway. Stimulation experiments using different sources of carbon (glucose, pyruvate, acetate and citrate) suggest that AST-C acts after pyruvate is transformed to citrate in the mitochondria. In vitro inhibition of the citrate mitochondrial carrier (CIC) mimicked the effect of AeaAST-C, and was overridden by addition of citrate or acetate. Our results provide compelling evidence that AeaAST-C inhibits JH III synthesis by blocking the CIC carrier that transports citrate from the mitochondria to the cytosol, obstructing the production of cytoplasmic acetyl-CoA that sustains JH III synthesis in the CA of mosquitoes.

  14. Juvenile hormone (JH) esterase of the mosquito Culex quinquefasciatus is not a target of the JH analog insecticide methoprene.

    PubMed

    Kamita, Shizuo G; Samra, Aman I; Liu, Jun-Yan; Cornel, Anthony J; Hammock, Bruce D

    2011-01-01

    Juvenile hormones (JHs) are essential sesquiterpenes that control insect development and reproduction. JH analog (JHA) insecticides such as methoprene are compounds that mimic the structure and/or biological activity of JH. In this study we obtained a full-length cDNA, cqjhe, from the southern house mosquito Culex quinquefasciatus that encodes CqJHE, an esterase that selectively metabolizes JH. Unlike other recombinant esterases that have been identified from dipteran insects, CqJHE hydrolyzed JH with specificity constant (k(cat)/K(M) ratio) and V(max) values that are common among JH esterases (JHEs). CqJHE showed picomolar sensitivity to OTFP, a JHE-selective inhibitor, but more than 1000-fold lower sensitivity to DFP, a general esterase inhibitor. To our surprise, CqJHE did not metabolize the isopropyl ester of methoprene even when 25 pmol of methoprene was incubated with an amount of CqJHE that was sufficient to hydrolyze 7,200 pmol of JH to JH acid under the same assay conditions. In competition assays in which both JH and methoprene were available to CqJHE, methoprene did not show any inhibitory effects on the JH hydrolysis rate even when methoprene was present in the assay at a 10-fold higher concentration relative to JH. Our findings indicated that JHE is not a molecular target of methoprene. Our findings also do not support the hypothesis that methoprene functions in part by inhibiting the action of JHE.

  15. Juvenile hormone analog enhances calling behavior, mating success, and quantity of volatiles released by Anastrepha obliqua (Diptera: Tephritidae).

    PubMed

    Chacón-Benavente, Roxana; López-Guillen, Guillermo; Hernández, Emilio; Rojas, Julio C; Malo, Edi A

    2013-04-01

    The application of a juvenile hormone analog, methoprene, to newly emerged adult males reduced the time required for sexual maturation and enhanced mating success in several species of tephritid fruit flies. In this work, we investigated the effect of topical methoprene application on West Indian fruit fly, Anastrepha obliqua (Macquart), male calling, mating, and volatile release. Males treated with topical methoprene exhibited sexual maturation and reproductive behavior 2 d earlier when compared with control males treated with acetone. Methoprene-treated males began calling and mating at 4 d old, whereas control males did not call and mate until 6 d old. The gas chromotography-mass spectrometry analysis of volatiles showed that during calling A. obliqua males consistently released four compounds; three of them were identified as (Z)-3-nonenol, (Z,E)-α-farnesene, (E,E)-α-farnesene, and a fourth compound with the appearance of a farnesene isomer. Both treated and control males released the same compounds, although treated males started to release volatiles before that control males. The results are discussed in view of possible methoprene application with the aim of reducing costs in fly emergence and release facilities before eventual release of A. obliqua in the field, thus improving the sterile insect technique.

  16. Juvenile hormone-dopamine systems for the promotion of flight activity in males of the large carpenter bee Xylocopa appendiculata.

    PubMed

    Sasaki, Ken; Nagao, Takashi

    2013-12-01

    The reproductive roles of dopamine and dopamine regulation systems are known in social hymenopterans, but the knowledge on the regulation systems in solitary species is still needed. To test the possibility that juvenile hormone (JH) and brain dopamine interact to trigger territorial flight behavior in males of a solitary bee species, the effects on biogenic amines of JH analog treatments and behavioral assays with dopamine injections in males of the large carpenter bee Xylocopa appendiculata were quantified. Brain dopamine levels were significantly higher in methoprene-treated males than in control males 4 days after treatment, but were not significantly different after 7 days. Brain octopamine and serotonin levels did not differ between methoprene-treated and control males at 4 and 7 days after treatment. Injection of dopamine caused significantly higher locomotor activities and a shorter duration for flight initiation in experimental versus control males. These results suggest that brain dopamine can be regulated by JH and enhances flight activities in males. The JH-dopamine system in males of this solitary bee species is similar to that of males of the highly eusocial honeybee Apis mellifera.

  17. Control of larval and egg development in Aedes aegypti with RNA interference against juvenile hormone acid methyl transferase.

    PubMed

    Van Ekert, Evelien; Powell, Charles A; Shatters, Robert G; Borovsky, Dov

    2014-11-01

    RNA interference (RNAi) is a powerful approach for elucidating gene functions in a variety of organisms, including mosquitoes and many other insects. Little has been done, however, to harness this approach in order to control adult and larval mosquitoes. Juvenile hormone (JH) plays a pivotal role in the control of reproduction in adults and metamorphism in larval mosquitoes. This report describes an approach to control Aedes aegypti using RNAi against JH acid methyl transferase (AeaJHAMT), the ultimate enzyme in the biosynthetic pathway of JH III that converts JH acid III (JHA III) into JH III. In female A. aegypti that were injected or fed jmtA dsRNA targeting the AeaJHAMT gene (jmtA) transcript, egg development was inhibited in 50% of the treated females. In mosquito larvae that were fed transgenic Pichia pastoris cells expressing long hair pin (LHP) RNA, adult eclosion was delayed by 3 weeks causing high mortality. Northern blot analyses and qPCR studies show that jmtA dsRNA causes inhibition of jmtA transcript in adults and larvae, which is consistent with the observed inhibition of egg maturation and larval development. Taken together, these results suggest that jmtA LHP RNA expressed in heat inactivated genetically modified P. pastoris cells could be used to control mosquito populations in the marsh.

  18. Synchronous vitellogenin expression and sexual maturation during migration are negatively correlated with juvenile hormone levels in Mythimna separata

    PubMed Central

    Xiao, Hai-Jun; Fu, Xiao-Wei; Liu, Yong-Qiang; Wu, Kong-Ming

    2016-01-01

    Annual migration of pests between different seasonal habitats can lead to serious crop damage. Reproductive immaturity is generally associated with the migratory process (oogenesis-flight syndrome), but the mechanism of reproductive development during migration varies unpredictably. Here, the vitellogenin gene (MsVg) and three key regulatory enzyme genes (MsJhamt, MsJheh and MsJhe) related to juvenile hormone (JH) synthesis and degradation were identified and characterized in Mythimna separata. The relative expression of MsVg varied significantly in response to seasonal changes and was significantly correlated with stages of ovarian development. The relatively low levels of JH titer did not differ significantly in male moths but slightly increased in female adults during the migratory season, which was consistent with changes in mRNA levels for MsJhamt, MsJheh and MsJhe. JH titer was negatively associated with relative seasonal levels of vitellogenin mRNA transcripts and with ovarian development in migrating M. separata. The synchrony of MsVg expression with sexual maturation highlighted the potential of MsVg transcript levels to serve as an index to monitor the adult reproductive status. In addition, the level of JH and sexual maturity were correlated with the extent of JH in regulating the MsVg expression and reproduction during seasonal northern and southern migration. PMID:27629246

  19. Juvenile Hormone Biosynthesis Gene Expression in the corpora allata of Honey Bee (Apis mellifera L.) Female Castes

    PubMed Central

    Rosa, Gustavo Conrado Couto; Moda, Livia Maria; Martins, Juliana Ramos; Bitondi, Márcia Maria Gentile; Hartfelder, Klaus; Simões, Zilá Luz Paulino

    2014-01-01

    Juvenile hormone (JH) controls key events in the honey bee life cycle, viz. caste development and age polyethism. We quantified transcript abundance of 24 genes involved in the JH biosynthetic pathway in the corpora allata-corpora cardiaca (CA-CC) complex. The expression of six of these genes showing relatively high transcript abundance was contrasted with CA size, hemolymph JH titer, as well as JH degradation rates and JH esterase (jhe) transcript levels. Gene expression did not match the contrasting JH titers in queen and worker fourth instar larvae, but jhe transcript abundance and JH degradation rates were significantly lower in queen larvae. Consequently, transcriptional control of JHE is of importance in regulating larval JH titers and caste development. In contrast, the same analyses applied to adult worker bees allowed us inferring that the high JH levels in foragers are due to increased JH synthesis. Upon RNAi-mediated silencing of the methyl farnesoate epoxidase gene (mfe) encoding the enzyme that catalyzes methyl farnesoate-to-JH conversion, the JH titer was decreased, thus corroborating that JH titer regulation in adult honey bees depends on this final JH biosynthesis step. The molecular pathway differences underlying JH titer regulation in larval caste development versus adult age polyethism lead us to propose that mfe and jhe genes be assayed when addressing questions on the role(s) of JH in social evolution. PMID:24489805

  20. Juvenile hormone-dopamine systems for the promotion of flight activity in males of the large carpenter bee Xylocopa appendiculata

    NASA Astrophysics Data System (ADS)

    Sasaki, Ken; Nagao, Takashi

    2013-12-01

    The reproductive roles of dopamine and dopamine regulation systems are known in social hymenopterans, but the knowledge on the regulation systems in solitary species is still needed. To test the possibility that juvenile hormone (JH) and brain dopamine interact to trigger territorial flight behavior in males of a solitary bee species, the effects on biogenic amines of JH analog treatments and behavioral assays with dopamine injections in males of the large carpenter bee Xylocopa appendiculata were quantified. Brain dopamine levels were significantly higher in methoprene-treated males than in control males 4 days after treatment, but were not significantly different after 7 days. Brain octopamine and serotonin levels did not differ between methoprene-treated and control males at 4 and 7 days after treatment. Injection of dopamine caused significantly higher locomotor activities and a shorter duration for flight initiation in experimental versus control males. These results suggest that brain dopamine can be regulated by JH and enhances flight activities in males. The JH-dopamine system in males of this solitary bee species is similar to that of males of the highly eusocial honeybee Apis mellifera.

  1. Larval Exposure to the Juvenile Hormone Analog Pyriproxyfen Disrupts Acceptance of and Social Behavior Performance in Adult Honeybees

    PubMed Central

    Fourrier, Julie; Deschamps, Matthieu; Droin, Léa; Alaux, Cédric; Fortini, Dominique; Beslay, Dominique; Le Conte, Yves; Devillers, James; Aupinel, Pierrick; Decourtye, Axel

    2015-01-01

    Background Juvenile hormone (JH) plays an important role in honeybee development and the regulation of age-related division of labor. However, honeybees can be exposed to insect growth regulators (IGRs), such as JH analogs developed for insect pest and vector control. Although their side effects as endocrine disruptors on honeybee larval or adult stages have been studied, little is known about the subsequent effects on adults of a sublethal larval exposure. We therefore studied the impact of the JH analog pyriproxyfen on larvae and resulting adults within a colony under semi-field conditions by combining recent laboratory larval tests with chemical analysis and behavioral observations. Oral and chronic larval exposure at cumulative doses of 23 or 57 ng per larva were tested. Results Pyriproxyfen-treated bees emerged earlier than control bees and the highest dose led to a significant rate of malformed adults (atrophied wings). Young pyriproxyfen-treated bees were more frequently rejected by nestmates from the colony, inducing a shorter life span. This could be linked to differences in cuticular hydrocarbon (CHC) profiles between control and pyriproxyfen-treated bees. Finally, pyriproxyfen-treated bees exhibited fewer social behaviors (ventilation, brood care, contacts with nestmates or food stocks) than control bees. Conclusion Larval exposure to sublethal doses of pyriproxyfen affected several life history traits of the honeybees. Our results especially showed changes in social integration (acceptance by nestmates and social behaviors performance) that could potentially affect population growth and balance of the colony. PMID:26171610

  2. Juvenile hormone analog technology: effects on larval cannibalism and the production of Spodoptera exigua (Lepidoptera: Noctuidae) nucleopolyhedrovirus.

    PubMed

    Elvira, Sonia; Williams, Trevor; Caballero, Primitivo

    2010-06-01

    The production of a multiple nucleopolyhedrovirus (SeMNPV) of the beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), has been markedly increased by using juvenile hormone analog (JHA) technology to generate a supernumerary sixth instar in the species. In the current study we compared the incidence of cannibalism in S. exigua fifth and sixth instars reared at low (two larvae per dish) and a high density (10 larvae per dish). The incidence of cannibalism was significantly higher in fifth instars compared with sixth instars and increased with rearing density on both instars. Infected larvae were more prone to become victims of cannibalism than healthy individuals in mixed groups comprising 50% healthy + 50% infected larvae in both instars reared at high density. Instar had a marked effect on occlusion body (OB) production because JHA-treated insects produced between 4.8- and 5.6-fold increase in OB production per dish compared with fifth instars at high and low densities, respectively. The insecticidal characteristics of OBs produced in JHA-treated insects, as indicated by LD50 values, were similar to those produced in untreated fourth or fifth instars. Because JHA technology did not increase the prevalence of cannibalism and had no adverse effect on the insecticidal properties of SeMNPV OBs, we conclude that the use of JHAs to generate a supernumerary instar is likely to be compatible with mass production systems that involve gregarious rearing of infected insects.

  3. Juvenile hormone biosynthesis gene expression in the corpora allata of honey bee (Apis mellifera L.) female castes.

    PubMed

    Bomtorin, Ana Durvalina; Mackert, Aline; Rosa, Gustavo Conrado Couto; Moda, Livia Maria; Martins, Juliana Ramos; Bitondi, Márcia Maria Gentile; Hartfelder, Klaus; Simões, Zilá Luz Paulino

    2014-01-01

    Juvenile hormone (JH) controls key events in the honey bee life cycle, viz. caste development and age polyethism. We quantified transcript abundance of 24 genes involved in the JH biosynthetic pathway in the corpora allata-corpora cardiaca (CA-CC) complex. The expression of six of these genes showing relatively high transcript abundance was contrasted with CA size, hemolymph JH titer, as well as JH degradation rates and JH esterase (jhe) transcript levels. Gene expression did not match the contrasting JH titers in queen and worker fourth instar larvae, but jhe transcript abundance and JH degradation rates were significantly lower in queen larvae. Consequently, transcriptional control of JHE is of importance in regulating larval JH titers and caste development. In contrast, the same analyses applied to adult worker bees allowed us inferring that the high JH levels in foragers are due to increased JH synthesis. Upon RNAi-mediated silencing of the methyl farnesoate epoxidase gene (mfe) encoding the enzyme that catalyzes methyl farnesoate-to-JH conversion, the JH titer was decreased, thus corroborating that JH titer regulation in adult honey bees depends on this final JH biosynthesis step. The molecular pathway differences underlying JH titer regulation in larval caste development versus adult age polyethism lead us to propose that mfe and jhe genes be assayed when addressing questions on the role(s) of JH in social evolution.

  4. Identification and characterization of a juvenile hormone (JH) response region in the JH esterase gene from the spruce budworm, Choristoneura fumiferana.

    PubMed

    Kethidi, Damodar R; Perera, Srini C; Zheng, S; Feng, Qi-Li; Krell, Peter; Retnakaran, Arthur; Palli, Subba R

    2004-05-07

    Using a differential display of mRNA technique we discovered that the juvenile hormone (JH) esterase gene (Cfjhe) from Choristoneura fumiferana is directly induced by juvenile hormone I (JH I), and the JH I induction is suppressed by 20-hydroxyecdysone (20E). To study the mechanism of action of these two hormones in the regulation of expression of this gene, we cloned the 1270-bp promoter region of the Cfjhe gene and identified a 30-bp region that is located between -604 and -574 and is sufficient to support both JH I induction and 20E suppression. This 30-bp region contains two conserved hormone response element half-sites separated by a 4-nucleotide spacer similar to the direct repeat 4 element and is designated as a putative juvenile hormone response element (JHRE). In CF-203 cells, a luciferase reporter placed under the control of JHRE and a minimal promoter was induced by JH I in a dose- and time-dependent manner. Moreover, 20E suppressed this JH I-induced luciferase activity in a dose- and time-dependent manner. Nuclear proteins isolated from JH I-treated CF-203 cells bound to JHRE and the binding was competed by a 100-fold excess of the cold probe but not by 100-fold excess of double-stranded oligonucleotides of unrelated sequence. JH I induced/modified nuclear proteins prior to their binding to JHRE and 20E suppressed this JH I induction/modification. These results suggest that the 30-bp JHRE identified in the Cfjhe gene promoter is sufficient to support JH induction and 20E suppression of the Cfjhe gene.

  5. Intergenerational effect of juvenile hormone on offspring in Pogonomyrmex harvester ants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Parents can influence the phenotypes of their offspring via a number of mechanisms. In harvester ants, whether female progeny develop into workers or daughter queens is strongly influenced by the age and temperature conditions experienced by their mother, which is associated with variation in mater...

  6. The influence of ovarian factors on the somatostatin-growth hormone system during the postnatal growth and sexual development in lambs.

    PubMed

    Wańkowska, Marta; Polkowska, Jolanta; Misztal, Tomasz; Romanowicz, Katarzyna

    2012-07-01

    The aim of the study was to elucidate the effects of ovarian hormones on somatostatin in the hypothalamic neurons and growth hormone (GH) secretion during the postnatal growth and development of sheep. The study was performed on 9-week-old (infantile) lambs that were ovary-intact (OVI) or ovariectomized (OVX) at 39 days of age, and on 16-week-old (juvenile) lambs that were OVI or OVX at 88 days of age. Hormones in neurons and somatotropic cells were assayed with immunohistochemistry and radioimmunoassay. Following ovariectomy, immunoreactive somatostatin was more abundant (p<0.05) in the hypothalamus of infantile lambs, whereas in juvenile lambs it was more abundant (p<0.05) in the periventricular nucleus but reduced (p<0.01) in the median eminence. In contrast to somatostatin in the hypothalamus, the content of immunoreactive GH in the hypophysis was less in OVX infantile lambs, but greater in OVX juvenile lambs (p<0.05). Basal blood serum concentrations of GH were greater (p<0.05) in OVX infantile lambs, whereas in OVX juvenile lambs, mean and basal concentrations of GH and amplitude of GH pulses were less than in OVI lambs (p<0.05). The postnatal increase in body weight was greatest in middle-late infancy (p<0.01). The body weight did not differ (p>0.05) between OVI and OVX lambs. In conclusion, ovarian factors may inhibit the GH secretion in infantile lambs but enhance the GH secretion in juvenile lambs. Transition to puberty, as related to the growth rate, appears to be due mainly to change in gonadal influence on the somatostatin neurosecretion. A stimulation of somatostatin output in the median eminence by gonadal factors in infancy is followed by a stimulation of somatostatin accumulation after infancy. Thus, ovarian factors modulate mechanisms within the somatotropic system of lambs to synchronize the somatic growth with sexual development.

  7. Variability in leptin and adrenal response in juvenile Steller sea lions (Eumetopias jubatus) to adrenocorticotropic hormone (ACTH) in different seasons.

    PubMed

    Mashburn, Kendall L; Atkinson, Shannon

    2008-01-15

    Eight free-ranging juvenile Steller sea lions (SSL; 6 males, 2 females; 14-20 months) temporarily held under ambient conditions at the Alaska SeaLife Center were physiologically challenged through exogenous administration of adrenocorticotropic hormone (ACTH). Four individuals (3 males, 1 female) underwent ACTH challenge in each of two seasons, summer and winter. Following ACTH injection serial blood and fecal samples were collected for up to 3 and 96 h, respectively. A radioimmunoassay (RIA) was validated for leptin, and using a previously validated RIA for cortisol, collected sera were analyzed for both cortisol and leptin. ACTH injection resulted in a 2.9-fold increase (P=0.164) in leptin which preceded a 3.2-fold increase (P=0.0290) in cortisol by 105 min in summer. In winter, a 1.7-fold increase in leptin (P=0.020) preceded a 2.1-fold increase (P=0.001) in serum cortisol by 45 min. Mean fecal corticosteroid maxima were 10.4 and 16.7-fold above baseline 28 and 12 h post-injection and returned to baseline 52 and 32 h post-injection, in summer and winter, respectively. Data indicate acute activity in juvenile adrenal glands is detectable in feces approximately 12-24 h post-stimulus in either season, with a duration of approximately 40 h in summer and 20 h in winter. Changes in serum cortisol proved statistically significant both seasons and elevated concentrations were detected by 30 min post-stimulus (baseline 64.8+/-4.2; peak 209.5+/-18.3 ng/ml: summer; baseline 87.0+/-15.7; peak 237.6+/-10.0 ng/ml: winter), whereas the changes that occurred in serum leptin proved to be significant only in winter (baseline 6.4+/-0.6; peak 18.7+/-7.0 ng/ml: summer; baseline 4.2+/-0.5; peak 7.5+/-0.6 ng/ml: winter). Changes in fecal corticosteroids proved significant only in summer (baseline 117.8+/-36.7; peak 1219.3+/-298.4 ng/g, P=0.038: summer; baseline 71.8+/-13.7; peak 1198.6+/-369.9 ng/g, P=0.053: winter) due to a high degree of individual variability in winter months. The

  8. On the factors influencing juvenile flatfish abundance in the lower Severn Estuary, England

    NASA Astrophysics Data System (ADS)

    Henderson, P. A.; Seaby, R. M. H.

    Bridgwater Bay within the Bristol Channel, Somerset, England is a nursery ground for sole, Solea solea, and dab, Limanda limanda, during the autumn and winter. Flounder, Platichthys flesus, both juveniles and adults, are common during the summer. Using a 13-year data set of fish in the bay, correlations were studied between climatic, predatory and competitive factors and juvenile flatfish abundance. The major factor was found to be seawater temperature. For sole, abundance was positively correlated with the temperature in the spawning period (April and May). For flounder, abundance was negatively correlated with average temperature during the previous year. For dab, average winter temperature over the spawning period was negatively correlated with juvenile abundance and with mean length observed during the following autumn. These climatic changes were also found to influence the abundance of a large number of other fish and crustacean species which were potential predators or competitors and which in some cases were significantly correlated with flatfish abundance. The data set was analysed using multiple correlation analysis. Multi-factorial models of population change which included interspecific and climatic factors were examined. Using first-order partial correlations it was possible to distinguish between different causal models. In every case it was found that inter-specific correlations were attributable to both species independently changing in abundance with temperature. No significant correlations between the abundance of potential predators or competitors and juvenile flatfish were detected.

  9. Alteration of thyroid hormone concentrations in juvenile Chinook salmon (Oncorhynchus tshawytscha) exposed to polybrominated diphenyl ethers, BDE-47 and BDE-99.

    PubMed

    Arkoosh, Mary R; Van Gaest, Ahna L; Strickland, Stacy A; Hutchinson, Greg P; Krupkin, Alex B; Dietrich, Joseph P

    2017-03-01

    Polybrominated diphenyl ethers (PBDEs) have been used as flame-retardants in consumer products and are currently detected in salmon globally. The two most predominant PBDE congeners found in salmon are BDE-47 (2,2',4,4'-tetrabromodiphenyl ether) and BDE-99 (2,2',4,4',5-pentabromodiphenyl ether). In the present study, groups of juvenile Pacific Chinook salmon were fed five environmentally relevant concentrations of either BDE-47 (0.3-552 ng total PBDEs/g food), BDE-99 (0.3-580 ng total PBDEs/g food), or nearly equal mixtures of both congeners (0.7-690 ng total PBDEs/g food) for 39-40 days. The concentrations of circulating total thyroid hormones, thyroxine (T4) and 3,5,3'-triiodothyronine (T3), were measured using a hormone-specific time-resolved fluoroimmunoassay to determine if PBDE exposure disrupts the hypothalamic-pituitary-thyroid endocrine axis. The concentrations of both circulating T4 and T3 were altered in juvenile salmon by dietary uptake of BDE-99. Exposure to BDE-47 did not alter either T3 or T4 circulating hormone concentrations. However, exposure to a mixture of BDE-47 and BDE-99 reduced T3 in fish with lower concentrations of total whole body PBDEs than with either congener alone at equivalent PBDE whole body concentrations. Accordingly, the disruption of PBDEs on circulating thyroid hormone concentrations has the potential to impact a number of critical functions in juvenile salmon including growth, parr-smolt transformation, and immunological processes.

  10. Plant-derived juvenile hormone III analogues and other sesquiterpenes from the stem bark of Cananga latifolia.

    PubMed

    Yang, Heejung; Kim, Hye Seong; Jeong, Eun Ju; Khiev, Piseth; Chin, Young-Won; Sung, Sang Hyun

    2013-10-01

    Juvenile hormone III (JH III) is a larval metamorphosis-regulating hormone present in most insect species. JH III was first isolated from the plant, Cyperus iria L., but the presence of JH III has not been reported in other plant species. In the present study, proof of the existence of JH III and its analogues from Cananga latifolia was established. From an aqueous MeOH extract of C. latifolia stem bark, six compounds were isolated along with nine known compounds. These were identified by using spectroscopic analyses as: (2E,6E,10R)-11-butoxy-10-hydroxy-3,7,11-trimethyldodeca-2,6-dienoic acid methyl ester, (2E,6E)-3,7,11-trimethyl-10-oxododeca-2,6-dienoic acid methyl ester, (2E)-3-methyl-5-[(1S,2R,6R)-1,2,6-trimethyl-3-oxocyclohexyl]-pent-2-enoic acid methyl ester, 1β-hydroxy-3-oxo-4β, 5α,7α-H-eudesmane 11-O-α-l-rhamnopyranoside, 4-epi-aubergenone 11-O-2',3'-di-O-acetyl-α-l-rhamnopyranoside and 4-epi-aubergenone 11-O-2',4'-di-O-acetyl-α-l-rhamnopyranoside. Three of the previously known compounds, (2E,6E,10R)-10-hydroxy-3,7,11-trimethyldodeca-2,6,11-trienoaic acid methyl ester, (2E,6E,10R)-10,11-dihydroxy-3,7,11-trimethyldodeca-2,6-dienoic acid and (2E,6S)-3-methyl-6-hydroxy-6-[(2R,5R)-5-(2-hydroxypropan-2-yl)-2-methyltetrahydrofuran-2-yl]-hex-2-enoaic acid methyl ester have now been found in a plant species. Ultra performance liquid chromatography-quadruple time-of-flight mass spectroscopy (UPLC-QTOF/MS) analysis of the chemical constituents of C. latifolia showed that several were predominant in the sub-fractions of a C. latifolia stem bark extract.

  11. Juvenile Hormone Differentially Regulates Two Grp78 Genes Encoding Protein Chaperones Required for Insect Fat Body Cell Homeostasis and Vitellogenesis.

    PubMed

    Luo, Maowu; Li, Dong; Wang, Zhiming; Guo, Wei; Kang, Le; Zhou, Shutang

    2017-03-29

    Juvenile hormone (JH) has a well-known role in stimulating insect vitellogenesis (i.e. yolk deposition) and oocyte maturation, but the molecular mechanisms of JH action in insect reproduction are unclear. Glucose-regulated protein of 78 kDa (Grp78) is a heat shock protein 70 kDa family member and one of the most abundant chaperones in the endoplasmic reticulum (ER) where it helps fold newly synthesized peptides. Because of its prominent role in protein folding and also ER stress, we hypothesized that Grp78 might be involved in fat body cell homeostasis and vitellogenesis and a regulatory target of JH. We report here that the migratory locust Locusta migratoria possesses two Grp78 genes that are differentially regulated by JH. We found that Grp78-1 is regulated by JH through Mcm4/7-dependent DNA replication and polyploidization, whereas Grp78-2 expression is directly activated by the JH-receptor complex comprising Methoprene-tolerant and Taiman proteins. Interestingly, Grp78-2 expression in the fat body is about 10-fold higher than that of Grp78-1 Knockdown of either Grp78-1 or Grp78-2 significantly reduced levels of vitellogenin (Vg) protein, accompanied by retarded maturation of oocytes. Depletion of both Grp78-1 and Grp78-2 resulted in ER stress and apoptosis in the fat body and in severely defective Vg synthesis and oocyte maturation. These results indicate a crucial role of Grp78 in JH-dependent vitellogenesis and egg production. The presence and differential regulation of two Grp78 genes in L. migratoria likely help accelerate the production of this chaperone in the fat body to facilitate folding of massively synthesized Vg and other proteins.

  12. Developmental link between sex and nutrition; doublesex regulates sex-specific mandible growth via juvenile hormone signaling in stag beetles.

    PubMed

    Gotoh, Hiroki; Miyakawa, Hitoshi; Ishikawa, Asano; Ishikawa, Yuki; Sugime, Yasuhiro; Emlen, Douglas J; Lavine, Laura C; Miura, Toru

    2014-01-01

    Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutrition-dependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its interaction with juvenile hormone (JH) signaling. doublesex genes encode transcription factors that orchestrate male and female specific trait development, and JH acts as a mediator between nutrition and mandible growth. We found that the Cmdsx gene regulates sex differentiation in the stag beetle. Knockdown of Cmdsx by RNA-interference in both males and females produced intersex phenotypes, indicating a role for Cmdsx in sex-specific trait growth. By combining knockdown of Cmdsx with JH treatment, we showed that female-specific splice variants of Cmdsx contribute to the insensitivity of female mandibles to JH: knockdown of Cmdsx reversed this pattern, so that mandibles in knockdown females were stimulated to grow by JH treatment. In contrast, mandibles in knockdown males retained some sensitivity to JH, though mandibles in these individuals did not attain the full sizes of wild type males. We suggest that moderate JH sensitivity of mandibular cells may be the default developmental state for both sexes, with sex-specific Dsx protein decreasing sensitivity in females, and increasing it in males. This study is the first to demonstrate a causal link between the sex determination and JH signaling pathways, which clearly interact to determine the

  13. Developmental Link between Sex and Nutrition; doublesex Regulates Sex-Specific Mandible Growth via Juvenile Hormone Signaling in Stag Beetles

    PubMed Central

    Gotoh, Hiroki; Miyakawa, Hitoshi; Ishikawa, Asano; Ishikawa, Yuki; Sugime, Yasuhiro; Emlen, Douglas J.; Lavine, Laura C.; Miura, Toru

    2014-01-01

    Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutrition-dependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its interaction with juvenile hormone (JH) signaling. doublesex genes encode transcription factors that orchestrate male and female specific trait development, and JH acts as a mediator between nutrition and mandible growth. We found that the Cmdsx gene regulates sex differentiation in the stag beetle. Knockdown of Cmdsx by RNA-interference in both males and females produced intersex phenotypes, indicating a role for Cmdsx in sex-specific trait growth. By combining knockdown of Cmdsx with JH treatment, we showed that female-specific splice variants of Cmdsx contribute to the insensitivity of female mandibles to JH: knockdown of Cmdsx reversed this pattern, so that mandibles in knockdown females were stimulated to grow by JH treatment. In contrast, mandibles in knockdown males retained some sensitivity to JH, though mandibles in these individuals did not attain the full sizes of wild type males. We suggest that moderate JH sensitivity of mandibular cells may be the default developmental state for both sexes, with sex-specific Dsx protein decreasing sensitivity in females, and increasing it in males. This study is the first to demonstrate a causal link between the sex determination and JH signaling pathways, which clearly interact to determine the

  14. Precocious sexual signalling and mating in Anastrepha fraterculus (Diptera: Tephritidae) sterile males achieved through juvenile hormone treatment and protein supplements.

    PubMed

    Liendo, M C; Devescovi, F; Bachmann, G E; Utgés, M E; Abraham, S; Vera, M T; Lanzavecchia, S B; Bouvet, J P; Gómez-Cendra, P; Hendrichs, J; Teal, P E A; Cladera, J L; Segura, D F

    2013-02-01

    Sexual maturation of Anastrepha fraterculus is a long process. Methoprene (a mimic of juvenile hormone) considerably reduces the time for sexual maturation in males. However, in other Anastrepha species, this effect depends on protein intake at the adult stage. Here, we evaluated the mating competitiveness of sterile laboratory males and females that were treated with methoprene (either the pupal or adult stage) and were kept under different regimes of adult food, which varied in the protein source and the sugar:protein ratio. Experiments were carried out under semi-natural conditions, where laboratory flies competed over copulations with sexually mature wild flies. Sterile, methoprene-treated males that reached sexual maturity earlier (six days old), displayed the same lekking behaviour, attractiveness to females and mating competitiveness as mature wild males. This effect depended on protein intake. Diets containing sugar and hydrolyzed yeast allowed sterile males to compete with wild males (even at a low concentration of protein), while brewer´s yeast failed to do so even at a higher concentration. Sugar only fed males were unable to achieve significant numbers of copulations. Methoprene did not increase the readiness to mate of six-day-old sterile females. Long pre-copulatory periods create an additional cost to the management of fruit fly pests through the sterile insect technique (SIT). Our findings suggest that methoprene treatment will increase SIT effectiveness against A. fraterculus when coupled with a diet fortified with protein. Additionally, methoprene acts as a physiological sexing method, allowing the release of mature males and immature females and hence increasing SIT efficiency.

  15. Comparative ovarian microarray analysis of juvenile hormone-responsive genes in water flea Daphnia magna: potential targets for toxicity.

    PubMed

    Toyota, Kenji; Williams, Timothy D; Sato, Tomomi; Tatarazako, Norihisa; Iguchi, Taisen

    2017-03-01

    The freshwater zooplankton Daphnia magna has been extensively employed in chemical toxicity tests such as OECD Test Guidelines 202 and 211. Previously, it has been demonstrated that the treatment of juvenile hormones (JHs) or their analogues to female daphnids can induce male offspring production. Based on this finding, a rapid screening method for detection of chemicals with JH-activity was recently developed using adult D. magna. This screening system determines whether a chemical has JH-activity by investigating the male offspring inducibility. Although this is an efficient high-throughput short-term screening system, much remains to be discovered about JH-responsive pathways in the ovary, and whether different JH-activators act via the same mechanism. JH-responsive genes in the ovary including developing oocytes are still largely undescribed. Here, we conducted comparative microarray analyses using ovaries from Daphnia magna treated with fenoxycarb (Fx; artificial JH agonist) or methyl farnesoate (MF; a putative innate JH in daphnids) to elucidate responses to JH agonists in the ovary, including developing oocytes, at a JH-sensitive period for male sex determination. We demonstrate that induction of hemoglobin genes is a well-conserved response to JH even in the ovary, and a potential adverse effect of JH agonist is suppression of vitellogenin gene expression, that might cause reduction of offspring number. This is the first report demonstrating different transcriptomics profiles from MF and an artificial JH agonist in D. magna ovary, improving understanding the tissue-specific mode-of-action of JH. Copyright © 2016 John Wiley & Sons, Ltd.

  16. Juvenile hormone biosynthesis, oocyte growth and vitellogenin accumulation in Choristoneura fumiferana and C. rosaceana: a comparative study.

    PubMed

    Delisle, J; Cusson, M

    1999-06-01

    We assessed the effects of age and mating status on in vitro juvenile hormone (JH) biosynthesis, oocyte growth, egg production and vitellogenin (Vg) accumulation in the tortricid moths, Choristoneura fumiferana and C. rosaceana. To determine whether vitellogenesis is dependent on the presence of JH, we also examined the effects of decapitation and JH analog treatments on egg production. In both species, the corpora allata (CA) of adult females released fmol quantities of JH, with JH II being the major homolog produced. The CA began producing detectable quantities of JH around the time of emergence. Full activation of the CA was observed a few hours sooner in C. fumiferana than in C. rosaceana. In pharate adults and young virgin females of both species, growth of the basal oocyte reflected changes in CA activity. Decapitation of newly emerged females significantly reduced egg production, but treatment of decapitated females with the JH analog methoprene resulted in egg production that was similar to (C. fumiferana) or greater than (C. rosaceana) that of controls, indicating that JH is required for oocyte maturation. Vg was first observed in the hemolymph before the presumptive time of CA activation, suggesting that the synthesis of this protein is not dependent on JH. The presence of normal quantities of Vg in the hemolymph of pupae decapitated before CA activation confirmed this hypothesis. The Vg titer underwent a transient decline following CA activation and was significantly lower in mated than in virgin females of both species 3 and 5 days after copulation. Since CA activation at emergence and mating are both expected to cause a rise in the JH titer, we suggest that the declines in the levels of Vg result from JH-enhanced Vg uptake by the developing oocytes. Mating induced a significant increase in egg production but had no measurable impact on rates of JH biosynthesis in vitro.

  17. Functional significance of parasitism-induced suppression of juvenile hormone esterase activity in developmentally delayed Choristoneura fumiferana larvae.

    PubMed

    Cusson, M; Laforge, M; Miller, D; Cloutier, C; Stoltz, D

    2000-03-01

    The parasitic wasp Tranosema rostrale transmits a polydnavirus (PDV) to its host, Choristoneura fumiferana, during oviposition. Last-instar C. fumiferana larvae parasitized by T. rostrale early in the stadium fail to undergo metamorphosis, and injection of the wasp's calyx fluid (CxF; contains PDV) into healthy caterpillars induces a dose-dependent delay in initiation of metamorphosis (D. Doucet and M. Cusson, 1996, Entomol. Exp. Appl. 81, 21-30). In the present work, parasitization and injection of CxF (0.5 female equivalent) on the first day of the last stadium both prevented the rise in hemolymph 20-hydroxyecdysone (20HE) titer observed between day 4 and day 7 in control and saline-injected larvae. Similarly, juvenile hormone esterase (JHE) activity was depressed following parasitization or CxF injection, whereas control larvae displayed a peak on day 4. However, neither parasitism nor injection of CxF on day 1 prevented the JH-producing glands from turning off during the first half of the last stadium. Likewise, low but clearly detectable JH titers were observed in the first hours following the molt but very low titers, at or near the detection limit of our radioimmunoassay, were seen in both control and parasitized larvae on day 4. Prothoracic glands showed no apparent sign of degeneration 4 days after injection of CxF but had significantly smaller cells than saline-injected larvae 7 days postinjection. It is not clear whether this was a direct effect of T. rostrale PDV. Thus, disruption of spruce budworm metamorphosis by T. rostrale CxF involves depression of 20HE titers but is not associated with a measurable increase in the level of JH, as shown for some other host-parasitoid systems. In view of the latter observation, we put forward three hypotheses regarding the functional significance of the observed suppression of JHE activity in developmentally arrested C. fumiferana larvae.

  18. Expressional and functional analysis of CYP15A1, a juvenile hormone epoxidase, in the red flour beetle Tribolium castaneum.

    PubMed

    Minakuchi, Chieka; Ishii, Fumika; Washidu, Yumiko; Ichikawa, Akio; Tanaka, Toshiharu; Miura, Ken; Shinoda, Tetsuro

    2015-09-01

    Juvenile hormone (JH) is synthesized and secreted by the corpora allata. In the final two steps of JH biosynthesis, farnesoic acid (FA) is converted to JH through methylation by JH acid O-methyltransferase (JHAMT) and epoxidation by the cytochrome P450 enzyme CYP15. In the present study, we identified a homolog of CYP15 from the red flour beetle Tribolium castaneum (TcCYP15A1), and analyzed its expression as well as its role in JH biosynthesis. Quantitative RT-PCR analysis showed that the level of TcCYP15A1 mRNA was high in the embryonic stage as well as in the middle of the final larval instar. In the embryonic stage, the transcript level of TcCYP15A1 started to increase 30h after egg laying (AEL), peaked 54-60h AEL, and was followed by an increase of TcJHAMT mRNA, suggesting that JH biosynthesis started at this time point. TcCYP15A1 mRNA was present, but not exclusively so in the larval corpora allata. The recombinant TcCYP15A1 protein epoxidized both FA and methyl farnesoate (MF) in highly stereo-specific manners. These results confirmed that TcCYP15A1 is involved in JH biosynthesis. The RNAi-mediated knockdown of TcCYP15A1 in the pre-final larval instar did not result in precocious metamorphosis to pupa, indicating that MF may exhibit JH-like activity in order to maintain the larval status. The double knockdown of TcJHAMT and TcCYP15A1 resulted in pupae and adults with shorter wings, suggesting that the precursors of JH, JH acid and MF, may be essential for wing expansion.

  19. The influence of stress hormones on fear circuitry.

    PubMed

    Rodrigues, Sarina M; LeDoux, Joseph E; Sapolsky, Robert M

    2009-01-01

    Fear arousal, initiated by an environmental threat, leads to activation of the stress response, a state of alarm that promotes an array of autonomic and endocrine changes designed to aid self-preservation. The stress response includes the release of glucocorticoids from the adrenal cortex and catecholamines from the adrenal medulla and sympathetic nerves. These stress hormones, in turn, provide feedback to the brain and influence neural structures that control emotion and cognition. To illustrate this influence, we focus on how it impacts fear conditioning, a behavioral paradigm widely used to study the neural mechanisms underlying the acquisition, expression, consolidation, reconsolidation, and extinction of emotional memories. We also discuss how stress and the endocrine mediators of the stress response influence the morphological and electrophysiological properties of neurons in brain areas that are crucial for fear-conditioning processes, including the amygdala, hippocampus, and prefrontal cortex. The information in this review illuminates the behavioral and cellular events that underlie the feedforward and feedback networks that mediate states of fear and stress and their interaction in the brain.

  20. Examination of the influence of juvenile Atlantic salmon on the feeding mode of juvenile steelhead in Lake Ontario tributaries

    USGS Publications Warehouse

    Johnson, James H.; Waldt, Emily M.

    2014-01-01

    We examined diets of 1204 allopatric and sympatric juvenile Atlantic salmon (Salmo salar) and steelhead (Oncorhynchus mykiss) in three tributaries of Lake Ontario. The diet composition of both species consisted primarily of ephemeropterans, trichopterans, and chironomids, although juvenile steelhead consumed more terrestrial invertebrates, especially at the sympatric sites. Subyearlings of both species consumed small prey (i.e. chironomids) whereas large prey (i.e. perlids) made up a higher percentage of the diet of yearlings. The diet of juvenile steelhead at the allopatric sites was more closely associated with the composition of the benthos than with the drift, but was about equally associated with the benthos and drift at the sympatric sites. The diet of both subyearling and yearling Atlantic salmon was more closely associated with the benthos than the drift at the sympatric sites. The evidence suggests that juvenile steelhead may subtly alter their feeding behavior in sympatry with Atlantic salmon. This behavioral adaptation may reduce competitive interactions between these species.

  1. Cyp15F1: a novel cytochrome P450 gene linked to juvenile hormone-dependent caste differention in the termite Reticulitermes flavipes.

    PubMed

    Tarver, Matthew R; Coy, Monique R; Scharf, Michael E

    2012-07-01

    Termites are eusocial insects that jointly utilize juvenile hormone (JH), pheromones, and other semiochemicals to regulate caste differentiation and achieve caste homeostasis. Prior EST sequencing from the symbiont-free gut transcriptome of Reticulitermes flavipes unexpectedly revealed a number of unique cytochrome P450 (Cyp) transcripts, including fragments of a Cyp15 family gene (Cyp15F1) with homology to other insect Cyp15s that participate in JH biosynthesis. The present study investigated the role of Cyp15F1 in termite caste polyphenism and specifically tested the hypothesis that it plays a role in JH-dependent caste differentiation. After assembling the full-length Cyp15F1 cDNA sequence, we (i) determined its mRNA tissue expression profile, (ii) investigated mRNA expression changes in response to JH and the caste-regulatory primer pheromones γ-cadinene (CAD) and γ-cadinenal (ALD), and (iii) used RNA interference (RNAi) in combination with caste differentiation bioassays to investigate gene function at the phenotype level. Cyp15F1 has ubiquitous whole-body expression (including gut tissue); is rapidly and sustainably induced from 3 h to 48 h by JH, CAD, and ALD; and functions at least in part by facilitating JH-dependent soldier caste differentiation. These findings provide the second example of a termite caste regulatory gene identified through the use of RNAi, and significantly build upon our understanding of termite caste homeostatic mechanisms. These results also reinforce the concept of environmental caste determination in termites by revealing how primer pheromones, as socioenvironmental factors, can directly influence Cyp15 expression and caste differentiation.

  2. The effect of the juvenile hormone analog, fenoxycarb, on ecdysone receptor B1 expression in the midgut of Bombyx mori during larval-pupal metamorphosis.

    PubMed

    Goncu, Ebru; Parlak, Osman

    2012-04-24

    The Bombyx mori (Lepidoptera: Bombycidae) midgut undergoes remodeling during the larval-pupal metamorphosis. All metamorphic events in insects are controlled by mainly two hormones: 20-hydroxyecdysone (20E) and juvenile hormone (JH). Fenoxycarb, O-ethyl N-(2-(4-phenoxyphenoxy)-ethyl) carbamate, has been shown to be one of the most potent juvenile hormone analogs against a variety of insect species. In this study, the effect of fenoxycarb on EcR-B1 protein expression in the midgut of Bombyx mori during the remodeling processwas investigated. Fenoxycarb was topically treated to the beginning of the fifth instar Bombyx larvae. Its application prolonged the last instar and prevented metamorphic events. Analyses were performed from day 6 of the fifth instar to 24 hr after pupation in controls and to day 14 of the fifth instar in the fenoxycarb treated group. According to our results, the presence of EcR-B1 in the midguts of the fenoxycarb treated group during the feeding period suggested that EcR-B1 was involved in the functioning of larval cells and during this period fenoxycarb did not affect EcR-B1 status. Immediately after termination of the feeding stage, the amount of EcR-B1 protein increased, which indicated that it may strengthen the ecdysone signal for commitment of remodeling process. In the fenoxycarb treated group, its upregulation was delayed, which may be related to the inhibition of ecdysone secretion from the prothoracic gland.

  3. Hypermetabolic Conversion of Plant Oil into Water: Endothermic Biochemical Process Stimulated by Juvenile Hormone in the European Firebug, Pyrrhocoris apterus L.

    PubMed

    Sláma, Karel; Lukáš, Jan

    2016-01-01

    The physiological and biochemical mechanisms that enable insects to feed on dry food to secure enough water for larval growth were investigated. The study was carried out with a plethora of physiological methods, ranging from the simple volumetric determination of O2 consumption and water intake to more advanced methods such as scanning microrespirography and thermovision imaging of insect's body temperature. The experiments were done on the European firebug, Pyrrhocoris apterus, which feeds exclusively on dry linden seeds. In order to survive, it needs to drink water or suck a sap from plants occasionally. It was found that the young larval instars compensate the occasional water deficiency by the increased production of metabolic water. The juvenile hormone (JH)-dependent production of metabolic water, which was previously found in other species consuming dry food, was achieved in P. apterus by total metabolic combustion of the dietary lipid (neutral seed oil). The water-producing, hypermetabolic larvae were heated from inside by endothermic energy released from the uncoupling of oxidation from oxidative phosphorylation. The "warm", hypermetabolic larvae burning the dietary oil into CO2 and water showed the increased rates of respiratory metabolism. Microrespirographic recording of these larvae revealed the ratio of the respiratory quotient (RQ, CO2/O2) of 0.7, which indicated the breakdown of a pure triglyceride. The warm hypermetabolic larvae could be easily spotted and distinguished from the "cold" larvae on the screen of a thermovision camera. The last instar larvae lacking the JH were always only cold. They metabolized a carbohydrate substrate exclusively (RQ = 1.0), while the dietary lipid was stored in the fat body. In comparison with the hypermetabolic larvae of some other species fed on dry food, which exhibited the highest rates of O2 consumption ever recorded in a living organism (10-20 mL O2/g per hour), the metabolic difference between the warm and

  4. Infection by the microsporidium Vairimorpha necatrix (Microspora: Microsporidia) elevates juvenile hormone titres in larvae of the tomato moth, Lacanobia oleracea (Lepidoptera: Noctuidae).

    PubMed

    Down, Rachel E; Bell, Howard A; Bryning, Gareth; Kirkbride-Smith, Anne E; Edwards, John P; Weaver, Robert J

    2008-03-01

    The effects of infection by a microsporidium, Vairimorpha necatrix (Kramer), on the endogenous levels of juvenile hormones in tomato moth (Lacanobia oleracea L.) larvae were investigated. Levels of juvenile hormone II (JH II) were 10-fold greater in the infected larvae on day two of the sixth stadium but no significant difference was observed on day seven. Juvenile hormone I (JH I) was also detected in day two and day seven sixth instar infected larvae but was not detected in non-infected larvae. The duration of the fifth and sixth stadia was significantly longer for infected larvae when compared with non-infected larvae. No evidence was found to suggest that supernumerary moults are a feature of infection by V. necatrix in L. oleracea larvae. Experiments were performed to determine whether the elevation in JH levels, which probably prevents pupation, is an adaptive mechanism of the microsporidium for extending the growth phase of the host, thereby allowing increased spore production. A proportion of infected larvae were collected on days 9 and 24 of the sixth stadium and spore extracts prepared from each larva. These days represent the average duration of the sixth stadium required for uninfected larvae to reach pupation, and the average number of days that V. necatrix-infected larvae survive in the sixth stadium before dying from infection. The mean spore yields from infected larvae 24 days into the sixth stadium were significantly higher than the spore yields obtained from day nine sixth instar larvae. The hypothesis that V. necatrix manipulates host endocrinology (i.e. prolong the host larval state to maximise spore yield) is discussed in context with the results obtained.

  5. SEX-STEROID AND THYROID HORMONE CONCENTRATIONS IN JUVENILE ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) FROM CONTAMINATED AND REFERENCE LAKES IN FLORIDA, USA

    EPA Science Inventory

    Sex-steroid and thyroid hormones are critical regulators of growth and reproduction in all vertebrates, and several recent studies suggest that environmental chemicals can alter circulating concentrations of these hormones. This study examines plasma concentrations of estradiol-...

  6. Hormones

    MedlinePlus

    ... affect many different processes, including Growth and development Metabolism - how your body gets energy from the foods you eat Sexual function Reproduction Mood Endocrine glands, which are special groups of cells, make hormones. The major endocrine glands are the ...

  7. A coordinated expression of biosynthetic enzymes controls the flux of juvenile hormone precursors in the corpora allata of mosquitoes.

    PubMed

    Nouzova, Marcela; Edwards, Marten J; Mayoral, Jaime G; Noriega, Fernando G

    2011-09-01

    Juvenile hormone (JH) is a key regulator of metamorphosis and ovarian development in mosquitoes. Adult female Aedes aegypti mosquitoes show developmental and dynamically regulated changes of JH synthesis. Newly emerged females have corpora allata (CA) with low biosynthetic activity, but they produce high amounts of JH a day later; blood feeding results in a striking decrease in JH synthesis, but the CA returns to a high level of JH synthesis three days later. To understand the molecular bases of these dynamic changes we combined transcriptional studies of 11 of the 13 enzymes of the JH pathway with a functional analysis of JH synthesis. We detected up to a 1000-fold difference in the levels of mRNA in the CA among the JH biosynthetic enzymes studied. There was a coordinated expression of the 11 JH biosynthetic enzymes in female pupae and adult mosquito. Increases or decreases in transcript levels for all the enzymes resulted in increases or decreases of JH synthesis; suggesting that transcript changes are at least partially responsible for the dynamic changes of JH biosynthesis observed. JH synthesis by the CA was progressively increased in vitro by addition of exogenous precursors such as geranyl-diphosphate, farnesyl-diphosphate, farnesol, farnesal and farnesoic acid. These results suggest that the supply of these precursors and not the activity of the last 6 pathway enzymes is rate limiting in these glands. Nutrient reserves play a key role in the regulation of JH synthesis. Nutritionally deficient females had reduced transcript levels for the genes encoding JH biosynthetic enzymes and reduced JH synthesis. Our studies suggest that JH synthesis is controlled by the rate of flux of isoprenoids, which is the outcome of a complex interplay of changes in precursor pools, enzyme levels and external regulators such as nutrients and brain factors. Enzyme levels might need to surpass a minimum threshold to achieve a net flux of precursors through the biosynthetic

  8. Sexual difference in juvenile-hormone titer in workers leads to sex-biased soldier differentiation in termites.

    PubMed

    Toga, Kouhei; Hanmoto, Shutaro; Suzuki, Ryutaro; Watanabe, Dai; Miura, Toru; Maekawa, Kiyoto

    2016-04-01

    In termites, the soldier caste, with its specialized defensive morphology, is one of the most important characteristics for sociality. Most of the basal termite species have both male and female soldiers, and the soldier sex ratio is almost equal or only slightly biased. However, in the apical lineages (especially family Termitidae), there are many species that have soldiers with strongly biased sex ratio. Generally in termites, since high juvenile hormone (JH) titer is required for soldier differentiation from a worker via a presoldier stage, it was hypothesized that the biased soldier-sex ratio was caused by differences in JH sensitivity and/or JH titer between male and female workers. Therefore, we focused on the presoldier differentiation and the worker JH titer in species with only male soldiers (Nasutitermes takasagoensis) and with both male and female soldiers (Reticulitermes speratus) in natural conditions. In the former species, there are four types of workers; male minor, male medium, female medium and female major workers, and presoldiers differentiate from male minor workers. First, we tried to artificially induce presoldiers from male and female workers. In N. takasagoensis, the presoldier differentiation rate and mortality was significantly higher in male minor workers. Morphological analyses showed that both male and female induced presoldiers possessed normal soldier-specific morphologies. It was suggested that female workers, from which soldiers do not differentiate under natural conditions, also maintained the physiological and developmental potential for soldier differentiation. In R. speratus, however, no differences were observed in solder differentiation rate and mortality between male and female workers. Second, the JH titers of each sex/type of workers were quantified by high performance liquid chromatography-mass spectrometry in two different seasons (April and December). The results showed that, in N. takasagoensis, JH titer in male minor

  9. Synthesis of analogs of juvenile hormone on the basis of the telomerization reaction of piperylene with sulfones

    SciTech Connect

    Tolstikov, G.A.; Rozentsvet, O.A.; Pantukh, B.I.; Khalilov, L.M.

    1986-10-20

    In continuing the work on the study of the telomerization of 1,3-dienes with sulfones containing an active H atom, and also with the aim of synthesizing analogs of juvenile hormone (JH) based on the telomers obtained, they studied the catalytic telomerization of 1,3-pentadiene (piperylene) with ..beta..-substituted sulfonates. It was established that trans-piperlyene participates in the telomerization reaction with sulfones in the presence of the catalytic system PdCl/sub 2/(Ph/sub 3/P)/sub 2/-PhONa. Methyl 2-phenylsulfonyl-3,7-dimethyl-4(E), 9-decadienecarboxylate (II) is formed in a yield of 65% by the reaction of methyl phenylsulfonylacetate (I) with piperylene in the course of 20 h at 85/sup 0/C. The presence of absorption bands at 920 (CH/sub 2/=C) and 980 cm/sup -1/ (E-CH=CH) in the IR spectrum of compound (II) and the presence of a group of multiplet signals at delta 4.8-5.3 ppm in the PMR spectrum, corresponding to five protons of double bonds, indicate the addition of two molecules of piperylene to the molecule of the sulfone (I). The oxidation with oxygen on a Pd/Cu-catalyst proceeds smoothly to the methyl ketone (III); this clearly confirms the presence of the terminal C=C bond in the telomer (II). In the PMR spectrum of (II), notice is taken of the group of signals in the region of 3.30-3.53 ppm corresponding to three methoxy protons. There are three pairs of doublets (J = 7 Hz) in the region of 0.1-1.3 ppm which correspond to the methyl group. The complexity of the PMR spectrum is probably explained by the fact that the reaction leads to the formation of a complex mixture of diastereoisomers. As was to be expected, methyl 3,7-dimethyl-4,9-decadienoate (IV) is formed as the sole product with a yield of 70% in the desulfonation of the telomer (II) using Na/Hg in methanol according to the method of (5); the structure of (IV) was established with the aid of /sup 13/C NMR spectroscopy.

  10. Family-specific differences in growth rate and hepatic gene expression in juvenile triploid growth hormone (GH) transgenic Atlantic salmon (Salmo salar).

    PubMed

    Xu, Qingheng; Feng, Charles Y; Hori, Tiago S; Plouffe, Debbie A; Buchanan, John T; Rise, Matthew L

    2013-12-01

    Growth hormone transgenic (GHTg) Atlantic salmon (Salmo salar) have enhanced growth when compared to their non-transgenic counterparts, and this trait can be beneficial for aquaculture production. Biological confinement of GHTg Atlantic salmon may be achieved through the induction of triploidy (3N). The growth rates of triploid GH transgenic (3NGHTg) Atlantic salmon juveniles were found to significantly vary between families in the AquaBounty breeding program. In order to characterize gene expression associated with enhanced growth in juvenile 3NGHTg Atlantic salmon, a functional genomics approach (32K cDNA microarray hybridizations followed by QPCR) was used to identify and validate liver transcripts that were differentially expressed between two fast-growing 3NGHTg Atlantic salmon families (AS11, AS26) and a slow-growing 3NGHTg Atlantic salmon family (AS25); juvenile growth rate was evaluated over a 45-day period. Of 687 microarray-identified differentially expressed features, 143 (116 more highly expressed in fast-growing and 27 more highly expressed in slow-growing juveniles) were identified in the AS11 vs. AS25 microarray study, while 544 (442 more highly expressed in fast-growing and 102 more highly expressed in slow-growing juveniles) were identified in the AS26 vs. AS25 microarray study. Forty microarray features (39 putatively associated with fast growth and 1 putatively associated with slow growth) were present in both microarray experiment gene lists. The expression levels of 15 microarray-identified transcripts were studied using QPCR with individual RNA samples to validate microarray results and to study biological variability of transcript expression. The QPCR results agreed with the microarray results for 12 of 13 putative fast-growth associated transcripts, but QPCR did not validate the microarray results for 2 putative slow-growth associated transcripts. Many of the 39 microarray-identified genes putatively associated at the transcript expression

  11. Youth pathways to placement: the influence of gender, mental health need and trauma on confinement in the juvenile justice system.

    PubMed

    Espinosa, Erin M; Sorensen, Jon R; Lopez, Molly A

    2013-12-01

    Although the juvenile crime rate has generally declined, the involvement of girls in the juvenile justice system has been increasing. Possible explanations for this gender difference include the impact of exposure to trauma and mental health needs on developmental pathways and the resulting influence of youth's involvement in the justice system. This study examined the influence of gender, mental health needs and trauma on the risk of out-of-home placement for juvenile offenders. The sample included youth referred to three urban juvenile probation departments in Texas between January 1, 2007 and December 31, 2008 and who received state-mandated mental health screening (N = 34,222; 30.1 % female). The analysis revealed that, for both genders, elevated scores on the seven factor-analytically derived subscales of a mental health screening instrument (Alcohol and Drug Use, Depressed-Anxious, Somatic Complaints, Suicidal Ideation, Thought Disturbance, and Traumatic Experiences), especially related to past traumatic experiences, influenced how deeply juveniles penetrated the system. The findings suggest that additional research is needed to determine the effectiveness of trauma interventions and the implementation of trauma informed systems for youth involved with the juvenile justice system.

  12. Genetic and diurnal variation in the juvenile hormone titer in a wing-polymorphic cricket: implications for the evolution of life histories and dispersal.

    PubMed

    Zera, A J; Cisper, G

    2001-01-01

    The wing-polymorphic cricket, Gryllus firmus, contains (1) a flight-capable morph (LW(f)) with long wings and functional flight muscles, (2) a flightless morph with reduced wings and underdeveloped flight muscles (SW), and (3) a flightless morph with histolyzed flight muscles but with fully developed wings (LW(h)). The LW(f) morph differed genetically from the SW morph and phenotypically from the LW(h) morph in the size of flight muscles, ovarian growth during the first week of adulthood, and the hemolymph titer of juvenile hormone (JH). This is the first study to document that phenotypes that differ genetically in morphological aspects of dispersal capability and in ovarian growth also differ genetically in the titer of a hormone that potentially regulates those traits. The JH titer rose 9-100-fold during the photophase in the flight-capable LW(f) morph but did not change significantly during this time in either flightless morph. Prolonged elevation of the in vivo JH titer in flight-capable females, by topical application of a hormone analogue, caused a substantial increase in ovarian growth and histolysis of flight muscles. The short-term, diurnal rise in the JH titer in the dispersing morph may be a mechanism that allows JH to positively regulate nocturnal flight behavior, while not causing maladaptive histolysis of flight muscles and ovarian growth. This is the first demonstration of naturally occurring, genetically based variation for diurnal change in a hormone titer in any organism.

  13. Molecular cloning and developmental expression of the gene encoding juvenile hormone esterase in the yellow-spotted longicorn beetle, Psacothea hilaris.

    PubMed

    Munyiri, Florence N; Ishikawa, Yukio

    2007-05-01

    Juvenile hormone (JH) plays a key role in the regulation of growth, development, diapause and reproduction in insects. The regulation of JH titers in the insect body is therefore crucial throughout postembryonic development. One of the major pathways of JH metabolism is degradation by a highly selective enzyme, juvenile hormone esterase (JHE). We obtained a full-length cDNA encoding JHE in Psacothea hilaris (PhJHE). The complete PhJHE cDNA sequence is comprised of 1989 bp with an open reading frame of 1785 bp encoding 595 amino acid residues. The deduced protein sequence of PhJHE showed high homology with the Tenebrio molitor JHE (50% amino acid identity) and moderate homology with the Drosophila melanogaster JHE (34%). The PhJHE transcript was expressed mainly in the fat body. PhJHE transcript levels were low until day 3 of the 5th (final) larval instar, then steadily increased reaching a peak on day 13 (the prepupa stage), coinciding well with the peak hemolymph enzyme activity level. Sustained starvation of larvae after a period of feeding stimulated the expression of PhJHE mRNA while feeding the larvae with glucose downregulated its expression. These results are discussed with reference to the induction of precocious metamorphosis in this beetle by starvation.

  14. The Influence of Sex Hormones on Functional Cerebral Asymmetries in Postmenopausal Women

    ERIC Educational Resources Information Center

    Bayer, Ulrike; Erdmann, Gisela

    2008-01-01

    Studies investigating changes in functional cerebral asymmetries (FCAs) with hormonal fluctuations during the menstrual cycle in young women have led to controversial hypotheses about an influence of estrogen (E) and/or progesterone (P) on FCAs. Based on methodical, but also on principal problems in deriving conclusions about hormone effects from…

  15. Visual pigments and opsin expression in the juveniles of three species of fish (rainbow trout, zebrafish, and killifish) following prolonged exposure to thyroid hormone or retinoic acid.

    PubMed

    Suliman, Tarek; Novales Flamarique, Iñigo

    2014-01-01

    Thyroid hormone (TH) and retinoic acid (RA) are powerful modulators of photoreceptor differentiation during vertebrate retinal development. In the embryos and young juveniles of salmonid fishes and rodents, TH induces switches in opsin expression within individual cones, a phenomenon that also occurs in adult rodents following prolonged (12 week) hypothyroidism. Whether changes in TH levels also modulate opsin expression in the differentiated retina of fish is unknown. Like TH, RA is essential for retinal development, but its role in inducing opsin switches, if any, has not been studied. Here we investigate the action of TH and RA on single-cone opsin expression in juvenile rainbow trout, zebrafish, and killifish and on the absorbance of visual pigments in rainbow trout and zebrafish. Prolonged TH exposure increased the wavelength of maximum absorbance (λmax ) of the rod and the medium (M, green) and long (L, red) wavelength visual pigments in all fish species examined. However, unlike the opsin switch that occurred following TH exposure in the single cones of small juvenile rainbow trout (alevin), opsin expression in large juvenile rainbow trout (smolt), zebrafish, or killifish remained unchanged. RA did not induce any opsin switches or change the visual pigment absorbance of photoreceptors. Neither ligand altered cone photoreceptor densities. We conclude that RA has no effect on opsin expression or visual pigment properties in the differentiated retina of these fishes. In contrast, TH affected both single-cone opsin expression and visual pigment absorbance in the rainbow trout alevin but only visual pigment absorbance in the smolt and in zebrafish. The latter results could be explained by a combination of opsin switches and chromophore shifts from vitamin A1 to vitamin A2.

  16. Influence of sex steroid hormones on the adolescent brain and behavior: An update.

    PubMed

    Vigil, Pilar; Del Río, Juan Pablo; Carrera, BÁrbara; ArÁnguiz, Florencia C; Rioseco, Hernán; Cortés, Manuel E

    2016-08-01

    This review explains the main effects exerted by sex steroids and other hormones on the adolescent brain. During the transition from puberty to adolescence, these hormones participate in the organizational phenomena that structurally shape some brain circuits. In adulthood, this will propitiate some specific behavior as responses to the hormones now activating those neural circuits. Adolescence is, then, a critical "organizational window" for the brain to develop adequately, since steroid hormones perform important functions at this stage. For this reason, the adolescent years are very important for future behaviors in human beings. Changes that occur or fail to occur during adolescence will determine behaviors for the rest of one's lifetime. Consequently, understanding the link between adolescent behavior and brain development as influenced by sex steroids and other hormones and compounds is very important in order to interpret various psycho-affective pathologies. Lay Summary : The effect of steroid hormones on the development of the adolescent brain, and therefore, on adolescent behavior, is noticeable. This review presents their main activational and organizational effects. During the transition from puberty to adolescence, organizational phenomena triggered by steroids structurally affect the remodeling of brain circuits. Later in adulthood, these changes will be reflected in behavioral responses to such hormones. Adolescence can then be seen as a fundamental "organizational window" during which sex steroids and other hormones and compounds play relevant roles. The understanding of the relationship between adolescent behavior and the way hormones influence brain development help understand some psychological disorders.

  17. Naturally occurring insect growth regulators. II. Screening of insect and plant extracts as insect juvenile hormone mimics.

    PubMed

    Jacobson, M; Redfern, R E; Mills, G D

    1975-01-01

    Ethereal extracts prepared from the larvae, pupae, or eggs of 10 species of insects and from various parts of 343 species of higher plants were screened for juvenilizing effects against Tenebrio molitor and Oncopeltus fasciatus. Activity in both species was shown by an extract of the larvae of the stable fly, Stomoxys calcitrans, whereas an extract of the pupae was active in O. fasiatus only. Extracts of two plant species (Echinacea angustifolia roots and Chamaecyparis lawsoniana seeds) showed high juvenilizing activity in T. MOLITOR, AND EXtracts of five plant species (Clethra alnifolia stems, leaves, and fruits, Sassafras albidum roots and root bark, Eucalyptus camaldulensis stems and bark, Pinus rigida twigs and leaves, and Iris douglasiana roots, stems, and fruits) were highly active in O. fasciatus an extract of Tsuga canadensis leaves showed lower activity in this insect. Extracts of 16 species of plants showed high insecticidal activity (mortality) in O. fasciatus but lacked juvenilizing properties in both species of test insects.

  18. How hormones influence composition and physiological function of the brain-blood barrier.

    PubMed

    Hampl, R; Bičíková, M; Sosvorová, L

    2015-01-01

    Hormones exert many actions in the brain. Their access and effects in the brain are regulated by the blood-brain barrier (BBB). Hormones as other substances may enter the brain and vice versa either by paracellular way requiring breaching tight junctions stitching the endothelial cells composing the BBB, or by passage through the cells (transcellular way). Hormones influence both ways through their receptors, both membrane and intracellular, present on/in the BBB. In the review the main examples are outlined how hormones influence the expression and function of proteins forming the tight junctions, as well as how they regulate expression and function of major protein transporters mediating transport of various substances including hormone themselves.

  19. COMPARATIVE EMBRYONIC AND LARVAL DEVELOPMENTAL RESPONSES OF THE ESTUARINE GRASS SHRIMP (PALAEMONETES PUGIO) TO THE JUVENILE HORMONE AGONIST FENOXYCARB

    EPA Science Inventory

    This work was undertaken in order to develop a sensitive bioassay which indicates adverse effects of estuarine-applied insecticides on nontarget species. Newly developed 'third generation' insecticides are designed to act as hormone agonists and bind to endogenous insect hormone...

  20. VARIATION IN GROWTH, LIPID CLASS AND FATTY ACID COMPOSITION OF THE MUD CRAB, RHITHROPANOPEUS HARRISII (GOULD) DURING LARVAL DEVELOPMENT FOLLOWING EXPOSURE TO AN INSECT JUVENILE HORMONE ANALOG (FENOXYCARB(R))

    EPA Science Inventory

    This study examines the effects of fenoxycarb?, an insect juvenile hormone (JH) analog, on larval growth, and lipid class and fatty acid composition in first crabs of the mud crab Rhithropanopeus harrisii reared through total larval development in nominal water concentrations fr...

  1. Hypermetabolic Conversion of Plant Oil into Water: Endothermic Biochemical Process Stimulated by Juvenile Hormone in the European Firebug, Pyrrhocoris apterus L.

    PubMed Central

    Sláma, Karel; Lukáš, Jan

    2016-01-01

    The physiological and biochemical mechanisms that enable insects to feed on dry food to secure enough water for larval growth were investigated. The study was carried out with a plethora of physiological methods, ranging from the simple volumetric determination of O2 consumption and water intake to more advanced methods such as scanning microrespirography and thermovision imaging of insect’s body temperature. The experiments were done on the European firebug, Pyrrhocoris apterus, which feeds exclusively on dry linden seeds. In order to survive, it needs to drink water or suck a sap from plants occasionally. It was found that the young larval instars compensate the occasional water deficiency by the increased production of metabolic water. The juvenile hormone (JH)-dependent production of metabolic water, which was previously found in other species consuming dry food, was achieved in P. apterus by total metabolic combustion of the dietary lipid (neutral seed oil). The water-producing, hypermetabolic larvae were heated from inside by endothermic energy released from the uncoupling of oxidation from oxidative phosphorylation. The “warm”, hypermetabolic larvae burning the dietary oil into CO2 and water showed the increased rates of respiratory metabolism. Microrespirographic recording of these larvae revealed the ratio of the respiratory quotient (RQ, CO2/O2) of 0.7, which indicated the breakdown of a pure triglyceride. The warm hypermetabolic larvae could be easily spotted and distinguished from the “cold” larvae on the screen of a thermovision camera. The last instar larvae lacking the JH were always only cold. They metabolized a carbohydrate substrate exclusively (RQ = 1.0), while the dietary lipid was stored in the fat body. In comparison with the hypermetabolic larvae of some other species fed on dry food, which exhibited the highest rates of O2 consumption ever recorded in a living organism (10–20 mL O2/g per hour), the metabolic difference between

  2. Establishment of a short-term, in vivo screening method for detecting chemicals with juvenile hormone activity using adult Daphnia magna.

    PubMed

    Abe, Ryoko; Watanabe, Haruna; Yamamuro, Masumi; Iguchi, Taisen; Tatarazako, Norihisa

    2015-01-01

    Juvenile hormone (JH) and JH agonists have been shown to induce male offspring production in various daphnids, including Daphnia magna using OECD TG211. The critical period (about 1h) for JH action on ova in the parent's ovary to induce male offspring is existing at 7-8h later from ovulation. Therefore, we considered that adult D. magna could be used to produce a short-term screening method for detecting JH analogs. Using this method, we successfully demonstrated male offspring induction in the second broods after exposure to JH or JH agonists. After investigating the exposure time, the number of repetitions and the exposure concentration, we established a short-term, in vivo screening method for detecting JH analogs using adult D. magna. We examined positive and negative control chemicals using a previously developed method and verified the validity of our new testing method.

  3. The essence of insect metamorphosis and aging: electrical rewiring of cells driven by the principles of juvenile hormone-dependent Ca(2+)-homeostasis.

    PubMed

    De Loof, Arnold; De Haes, Wouter; Janssen, Tom; Schoofs, Liliane

    2014-04-01

    In holometabolous insects the fall to zero of the titer of Juvenile Hormone ends its still poorly understood "status quo" mode of action in larvae. Concurrently it initiates metamorphosis of which the programmed cell death of all internal tissues that actively secrete proteins, such as the fat body, midgut, salivary glands, prothoracic glands, etc. is the most drastic aspect. These tissues have a very well developed rough endoplasmic reticulum, a known storage site of intracellular Ca(2+). A persistent high [Ca(2+)]i is toxic, lethal and causal to apoptosis. Metamorphosis becomes a logical phenomenon if analyzed from: (1) the causal link between calcium toxicity and apoptosis; (2) the largely overlooked fact that at least some isoforms of Ca(2+)-ATPases have a binding site for farnesol-like endogenous sesquiterpenoids (FRS). The Ca(2+)-ATPase blocker thapsigargin, like JH a sesquiterpenoid derivative, illustrates how absence of JH might work. The Ca(2+)-homeostasis system is concurrently extremely well conserved in evolution and highly variable, enabling tissue-, developmental-, and species specificity. As long as JH succeeds in keeping [Ca(2+)]i low by keeping the Ca(2+)-ATPases pumping, it acts as "the status quo" hormone. When it disappears, its various inhibitory effects are lifted. The electrical wiring system of cells, in particular in the regenerating tissues, is subject to change during metamorphosis. The possibility is discussed that in vertebrates an endogenous farnesol-like sesquiterpenoid, probably farnesol itself, acts as a functional, but hitherto completely overlooked Juvenile anti-aging "Inbrome", a novel concept in signaling.

  4. Molecular cloning, characterization and expression analysis of two juvenile hormone esterase-like carboxylesterase cDNAs in Chinese mitten crab, Eriocheir sinensis.

    PubMed

    Xu, Yu; Zhao, Muzi; Deng, Yanfei; Yang, Yuanjie; Li, Xuguang; Lu, Quanping; Ge, Jiachun; Pan, Jianlin; Xu, Zhiqiang

    2017-03-01

    Precise regulation of methyl farnesoate (MF) titer is of prime importance throughout the crustacean life-cycle. Although the synthetic pathway of MF is well-documented, little is known about its degradation and recycling in crustaceans. Juvenile hormone esterase-like (JHE-like) carboxylesterase (CXE) is a key enzyme in MF degradation, thus playing a significant role in regulating the MF titer. We identified and characterized two cDNAs, Es-CXE1 and Es-CXE2, encoding JHE-like CXEs in Chinese mitten crab. Full-length cDNAs of Es-CXE1 and Es-CXE2 encode proteins composed of 584 and 597 amino acids, respectively, both of which contain a typical carboxylesterase domain. Alignment and phylogenetic analyses revealed that the Es-CXEs are highly similar to those of other crustaceans. To further validate their functions, we evaluated the mRNA expression patterns of the Es-CXEs in various tissues and in different physiological conditions. Tissue-specific expression analysis showed that the two Es-CXEs were predominantly expressed in the hepatopancreas and ovaries, which are the major tissues for MF metabolism. Es-CXE2 expression levels in the hepatopancreas and ovaries were about 100 and 25-fold higher, than the respective Es-CXE1 expressions. During ovarian rapid development stage, the global expressions of Es-CXEs were up-regulated in the hepatopancreas and down-regulated in the ovaries. After eyestalk ablation (ESA), the mRNA expressions of the two Es-CXEs were up-regulated in the hepatopancreas, further indicating their potential in degrading MF. Taken together, our results suggest that Es-CXEs, the key component of the juvenile hormone degradation pathway, may play vital roles in the development and reproduction of the Chinese mitten crab.

  5. Influence of diabetes surgery on gut hormones and incretins.

    PubMed

    Papamargaritis, D; Miras, A D; le Roux, Carel W

    2013-03-01

    The dramatic rise in the prevalence of obesity and type 2 diabetes mellitus (T2DM) has become a major global public health issue. There is increasing evidence that metabolic surgery is more effective than diet and exercise for diabetes remission and weight loss. Moreover, the rapid time course and disproportional degree of T2DM improvement after metabolic procedures compared with equivalent weight loss with conservative treatment, suggest surgery-specific, weight-independent effects on glucose homeostasis. Gut hormones has been proposed as one of the potential mechanisms for the weight-independent diabetes remission and long-term weight loss after these procedures. In this review we discuss the available current metabolic procedures and we review the current human data on changes in gut hormones after each metabolic procedure.

  6. The Influence of Stress on Juvenile Delinquency: Focusing on the Buffering Effects of Protective Factors among Korean Adolescents.

    PubMed

    Jeon, Hye Sook; Chun, JongSerl

    2017-01-01

    The present study sought to examine self-control, parental support, and peer support as internal and external protective factors that buffer the influence of adolescent stress on delinquency among Korean adolescents. To this end, the paper utilized the 1st-year data from the Korea Youth Panel Study (KYPS) conducted by the National Youth Policy Institute; the study surveyed a total of 3,449 2nd-year middle school students. The results of the hierarchical regression analysis indicated that despite high levels of stress, high self-control mitigated the negative influence of stress on delinquency in adolescents. In contrast, parental and peer support were only found to be directly influential on juvenile delinquency. Parental support had only negative influences on status delinquency, and peer support had positive influences on both status and serious delinquency. Based on these results, we propose implications for preventing and intervening with juvenile delinquency.

  7. Thyroid hormone influences muscle mechanics in carp (Cyprinus carpio) independently from SERCA activity.

    PubMed

    James, Rob S; Little, Alexander G; Tallis, Jason; Seebacher, Frank

    2016-09-15

    Thyroid hormone is a key regulator of metabolism, and in zebrafish, hypothyroidism decreases sustained and burst swimming performance. These effects are accompanied by decreases in both metabolic scope and the activity of sarco-endoplasmic reticulum ATPase (SERCA) in zebrafish. Our aim was to determine whether thyroid hormone affects skeletal muscle contractile function directly and whether these effects are mediated by influencing SERCA activity. We show that hypothyroidism reduces sustained locomotor performance but not sprint performance in carp (Cyprinus carpio). We accept our hypothesis that hypothyroidism reduces force production in isolated skeletal muscle, when compared with the thyroid hormone T2, but we reject the hypothesis that this effect is mediated by influencing SERCA activity. Blocking SERCA activity with thapsigargin reduced muscle fatigue resistance, but hypothyroidism had no effect on fatigue. Hence, thyroid hormone plays a role in determining isolated skeletal muscle mechanics, but its effects are more likely to be mediated by mechanisms other than affecting SERCA activity.

  8. Modelling the Influence of Long-Term Hydraulic Conditions on Juvenile Salmon Habitats in AN Upland Scotish River

    NASA Astrophysics Data System (ADS)

    Fabris, L.; Malcolm, I.; Millidine, K. J.; Buddendorf, B.; Tetzlaff, D.; Soulsby, C.

    2015-12-01

    Wild Atlantic salmon populations in Scottish rivers constitute an important economic and recreational resource, as well as being a key component of biodiversity. Salmon have very specific habitat requirements at different life stages and their distribution is therefore strongly influenced by a complex suite of biological and physical controls. Previous research has shown that stream hydrodynamics and channel morphology have a strong influence on the distribution and density of juvenile salmon. Here, we utilise a unique 20 year data set of spatially distributed juvenile salmon densities derived from annual electro-fishing surveys in an upland Scottish river. We examine to what extent the spatial and temporal variability of in-stream hydraulics regulates the spatial and temporal variability in the performance and density of juvenile salmon. A 2-D hydraulic model (River2D) is used to simulate water velocity and water depth under different flow conditions for seven different electro-fishing sites. The selected sites represent different hydromorphological environments including plane-bed, step-pool and pool riffle reaches. The bathymetry of each site was characterised using a total station providing an accurate DTM of the bed, and hydraulic simulations were driven by 20 year stream flow records. Habitat suitability curves, based on direct observations during electro-fishing surveys, were produced for a range of hydraulic indices for juvenile salmon. The hydraulic simulations showed marked spatial differences in juvenile habitat quality both within and between reaches. They also showed marked differences both within and between years. This is most evident in extreme years with wet summers when salmon feeding opportunities may be constrained. Integration of hydraulic habitat models, with fish preference curves and the long term hydrological data allows us to assess whether long-term changes in hydroclimate may be affecting juvenile salmonid populations in the study stream

  9. Body size and condition influence migration timing of juvenile Arctic grayling

    USGS Publications Warehouse

    Heim, Kurt C.; Wipfli, Mark S.; Whitman, Matthew S.; Seitz, Andrew C

    2016-01-01

    Freshwater fishes utilising seasonally available habitats within annual migratory circuits time movements out of such habitats with changing hydrology, although individual attributes of fish may also mediate the behavioural response to environmental conditions. We tagged juvenile Arctic grayling in a seasonally flowing stream on the Arctic Coastal Plain in Alaska and recorded migration timing towards overwintering habitat. We examined the relationship between individual migration date, and fork length (FL) and body condition index (BCI) for fish tagged in June, July and August in three separate models. Larger fish migrated earlier; however, only the August model suggested a significant relationship with BCI. In this model, 42% of variability in migration timing was explained by FL and BCI, and fish in better condition were predicted to migrate earlier than those in poor condition. Here, the majority (33%) of variability was captured by FL with an additional 9% attributable to BCI. We also noted strong seasonal trends in BCI reflecting overwinter mass loss and subsequent growth within the study area. These results are interpreted in the context of size and energetic state-specific risks of overwinter starvation and mortality (which can be very high in the Arctic), which may influence individuals at greater risk to extend summer foraging in a risky, yet prey rich, habitat. Our research provides further evidence that heterogeneity among individuals within a population can influence migratory behaviour and identifies potential risks to late season migrants in Arctic beaded stream habitats influenced by climate change and petroleum development.

  10. Effects of the juvenile hormone analogue methoprene on rate of behavioural development, foraging performance and navigation in honey bees (Apis mellifera).

    PubMed

    Chang, Lun-Hsien; Barron, Andrew B; Cheng, Ken

    2015-06-01

    Worker honey bees change roles as they age as part of a hormonally regulated process of behavioural development that ends with a specialised foraging phase. The rate of behavioural development is highly plastic and responsive to changes in colony condition such that forager losses, disease or nutritional stresses accelerate behavioural development and cause an early onset of foraging in workers. It is not clear to what degree the behavioural development of workers can be accelerated without there being a cost in terms of reduced foraging performance. Here, we compared the foraging performance of bees induced to accelerate their behavioural development by treatment with the juvenile hormone analogue methoprene with that of controls that developed at a normal rate. Methoprene treatment accelerated the onset of both flight and foraging behaviour in workers, but it also reduced foraging span, the total time spent foraging and the number of completed foraging trips. Methoprene treatment did not alter performance in a short-range navigation task, however. These data indicate a limitation to the physiological plasticity of bees, and a trade off between forager performance and the speed at which bees begin foraging. Chronic stressors will be expected to reduce the mean age of the foraging force, and therefore also reduce the efficiency of the foraging force. This interaction may explain why honey bee colonies react to sustained stressors with non-linear population decline.

  11. Juvenile hormone counteracts the bHLH-PAS transcription factors MET and GCE to prevent caspase-dependent programmed cell death in Drosophila.

    PubMed

    Liu, Ying; Sheng, Zhentao; Liu, Hanhan; Wen, Di; He, Qianyu; Wang, Sheng; Shao, Wei; Jiang, Rong-Jing; An, Shiheng; Sun, Yaning; Bendena, William G; Wang, Jian; Gilbert, Lawrence I; Wilson, Thomas G; Song, Qisheng; Li, Sheng

    2009-06-01

    Juvenile hormone (JH) regulates many developmental and physiological events in insects, but its molecular mechanism remains conjectural. Here we report that genetic ablation of the corpus allatum cells of the Drosophila ring gland (the JH source) resulted in JH deficiency, pupal lethality and precocious and enhanced programmed cell death (PCD) of the larval fat body. In the fat body of the JH-deficient animals, Dronc and Drice, two caspase genes that are crucial for PCD induced by the molting hormone 20-hydroxyecdysone (20E), were significantly upregulated. These results demonstrated that JH antagonizes 20E-induced PCD by restricting the mRNA levels of Dronc and Drice. The antagonizing effect of JH on 20E-induced PCD in the fat body was further confirmed in the JH-deficient animals by 20E treatment and RNA interference of the 20E receptor EcR. Moreover, MET and GCE, the bHLH-PAS transcription factors involved in JH action, were shown to induce PCD by upregulating Dronc and Drice. In the Met- and gce-deficient animals, Dronc and Drice were downregulated, whereas in the Met-overexpression fat body, Dronc and Drice were significantly upregulated leading to precocious and enhanced PCD, and this upregulation could be suppressed by application of the JH agonist methoprene. For the first time, we demonstrate that JH counteracts MET and GCE to prevent caspase-dependent PCD in controlling fat body remodeling and larval-pupal metamorphosis in Drosophila.

  12. Effects of hypophysectomy and substitution with growth hormone, prolactin, and thyroxine on growth and deposition in juvenile frogs, Xenopus laevis.

    PubMed

    Nybroe, O; Rosenkilde, P; Ryttersgaard, L

    1985-02-01

    Growth was studied in young metamorphosed frogs, Xenopus laevis, following hypophysectomy and substitution with mammalian growth hormone (bGH or pGH), mammalian prolactin (oPRL), and thyroxine. Hypophysectomy reduced growth (weight and length increase). GH and PRL proved equally efficient in restoring growth and in mobilizing energy stores (fat bodies and liver glycogen). No synergistic effects between GH and PRL could be observed. GH exerted its growth-promoting effects by increasing gross food conversion efficiency (weight increase/food intake), but did not stimulate appetite. Moderate GH doses given to a group of frogs in growth stagnation exerted moderate metabolic effects, and may have stimulated appetite in some animals, but did not increase body size significantly. Thyroxine was unable to promote growth, but increased mobilization of energy stores. Hypophysectomy and hormone substitution affected feeding behavior. The nature of the actions of pituitary somatotropic hormones and of thyroxine on growth and deposition is discussed.

  13. Dietary contaminant exposure affects plasma testosterone, but not thyroid hormones, vitamin A, and vitamin E, in male juvenile arctic foxes (Vulpes lagopus).

    PubMed

    Hallanger, Ingeborg G; Jørgensen, Even H; Fuglei, Eva; Ahlstrøm, Øystein; Muir, Derek C G; Jenssen, Bjørn Munro

    2012-01-01

    Levels of persistent organic pollutants (POP), such as polychlorinated biphenyls (PCB), are high in many Arctic top predators, including the Arctic fox (Vulpes lagopus). The aim of this study was to examine possible endocrine-disruptive effects of dietary POP exposure in male juvenile Arctic foxes in a controlled exposure experiment. The study was conducted using domesticated farmed blue foxes (Vulpes lagopus) as a model species. Two groups of newly weaned male foxes received a diet supplemented with either minke whale (Baleneoptera acutorostrata) blubber that was naturally contaminated with POP (exposed group, n = 5 or 21), or pork (Sus scrofa) fat (control group, n = 5 or 21). When the foxes were 6 mo old and had received the 2 diets for approximately 4 mo (147 d), effects of the dietary exposure to POP on plasma concentrations of testosterone (T), thyroid hormones (TH), thyroid-stimulating hormone (TSH), retinol (vitamin A), and tocopherol (viramin E) were examined. At sampling, the total body concentrations of 104 PCB congeners were 0.1 ± 0.03 μg/g lipid weight (l.w.; n = 5 [mean ± standard deviation]) and 1.5 ± 0.17 μg/g l.w. (n = 5) in the control and exposed groups, respectively. Plasma testosterone concentrations in the exposed male foxes were significantly lower than in the control males, being approximately 25% of that in the exposed foxes. There were no between-treatment differences for TH, TSH, retinol, or tocopherol. The results suggest that the high POP levels experienced by costal populations of Arctic foxes, such as in Svalbard and Iceland, may result in delayed masculine maturation during adolescence. Sex hormone disruption during puberty may thus have lifetime consequences on all aspects of reproductive function in adult male foxes.

  14. Effect of a peri-juvenile exposure to Triclosan on serum androgens and thyroid hormone in the male Wistar rat

    EPA Science Inventory

    Triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) is a potent antibacterial and antifungal compound that is widely used in personal care products. Studies testing triclosan exposure in the bullfrog showed altered thyroid hormone homeostasis. More recently, triclosan has been s...

  15. Influences of sex, incubation temperature, and environmental quality on gonadal estrogen and androgen receptor messenger RNA expression in juvenile American alligators (Alligator mississippiensis).

    PubMed

    Moore, Brandon C; Milnes, Matthew R; Kohno, Satomi; Katsu, Yoshinao; Iguchi, Taisen; Guillette, Louis J

    2010-01-01

    Gonadal steroid hormone receptors play a vital role in transforming ligand signals into gene expression. We have shown previously that gonads from wild-caught juvenile alligators express greater levels of estrogen receptor 1 (ESR1) than estrogen receptor 2 (ESR2). Furthermore, sexually dimorphic ESR2 mRNA expression (female > male) observed in animals from the reference site (Lake Woodruff, FL, USA) was lost in alligators from the contaminated Lake Apopka (FL, USA). We postulated that environmental contaminant exposure could influence gonadal steroid hormone receptor expression. Here, we address questions regarding gonadal estrogen and androgen receptor (AR) mRNA expression in 1-yr-old, laboratory-raised alligators. What are relative expression levels within gonads? Do these levels vary between sexes or incubation temperatures? Can contaminant exposure change these levels? We observed a similar pattern of expression (ESR1 > AR > ESR2) in ovary and testis. However, both incubation temperature and environment modulated expression. Males incubated at 33.5 degrees C expressed greater AR levels than females incubated at 30 degrees C; dimorphic expression was not observed in animals incubated at 32 degrees C. Compared to Lake Woodruff alligators, Lake Apopka animals of both sexes showed lesser ESR2 mRNA expression levels. Employing cluster analyses, we integrated these receptor expression patterns with those of steroidogenic factors. Elevated ESR2 and CYP19A1 expressions were diagnostic of alligator ovary, whereas elevated HSD3B1, CYP11A1, and CYP17A1 expressions were indicative of testis. In contrast, AR, ESR1, and NR5A1 showed variable expressions that were not entirely associated with sex. These findings demonstrate that the mRNA expression of receptors required for steroid hormone signaling are modified by exposure to environmental factors, including temperature and contaminants.

  16. Influence of parathyroid hormone on bone cell ultrastructure

    SciTech Connect

    Matthews, J.L.; Talmage, R.V.

    1981-05-01

    A study in rats demonstrated that morphologic changes in the bone osteocytes and osteoblasts are produced following parathyroid hormone (PTH) injection into thyroparathyroidectomized animals. It further showed that similar changes occur in normal rats as the result of extended fasting. The most significant morphologic alterations involved surface microvilli and blebs as determined by scanning electron microscopy. Transmission electron microscopy studies showed alterations in the cisternae of the rough endoplasmic reticulum. Additionally, cell shape varied markedly from the control cuboidal morphology. These morphologic changes occurred during peak periods of plasma calcium change and returned to control morphology as plasma calcium levels normalized. The study supports the concept that osteocytes and lining cells on the surface of bone play a role in maintenance of plasma calcium concentrations. (JMT)

  17. Influence of Photoperiod on Hormones, Behavior, and Immune Function

    PubMed Central

    Walton, James C.; Weil, Zachary M.; Nelson, Randy J.

    2011-01-01

    Photoperiodism is the ability of plants and animals to measure environmental day length to ascertain time of year. Central to the evolution of photoperiodism in animals is the adaptive distribution of energetically challenging activities across the year to optimize reproductive fitness while balancing the energetic tradeoffs necessary for seasonally- appropriate survival strategies. The ability to accurately predict future events requires endogenous mechanisms to permit physiological anticipation of annual conditions. Day length provides a virtually noise free environmental signal to monitor and accurately predict time of the year. In mammals, melatonin provides the hormonal signal transducing day length. Duration of pineal melatonin is inversely related to day length and its secretion drives enduring changes in many physiological systems, including the HPA, HPG, and brain-gut axes, the autonomic nervous system, and the immune system. Thus, melatonin is the fulcrum mediating redistribution of energetic investment among physiological processes to maximize fitness and survival. PMID:21156187

  18. Juvenile angiofibroma

    MedlinePlus

    Nasal tumor; Angiofibroma - juvenile; Benign nasal tumor; Juvenile nasal angiofibroma; JNA ... Juvenile angiofibroma is not very common. It is most often found in adolescent boys. The tumor contains ...

  19. The influence of pituitary, adrenal, and parathyroid hormones on hemostasis and thrombosis.

    PubMed

    Squizzato, Alessandro; Van Zaane, Bregje; Gerdes, Victor E A; Büller, Harry R

    2011-02-01

    Endocrine disorders can influence the hemostatic balance. Abnormal coagulation test results have been observed in patients with abnormal hormone levels. The present review updates the available evidence on the influence of pituitary, adrenal, and parathyroid hormones on the coagulation and the fibrinolytic system, and their possible clinical implications. The literature supports a possible relevant clinical effect of the imbalance between coagulation and fibrinolysis on thrombotic events in endogenous Cushing's syndrome. An effect on markers of coagulation and fibrinolysis has been shown for hyperprolactinemia, growth hormone excess or deficiency, exogenous hypercortisolism, pheochromocytoma, primary hyperaldosteronism, and hyperparathyroidism. However, the clinical relevance is still unproven. Until definitive evidence is available, clinicians should be aware of the possibility that endocrine disorders may be risk factors for thrombotic events.

  20. Influence of Thyroid Hormone Disruption on the Incidence of Shingles

    PubMed Central

    Ajavon, Amakoe; Killian, Dennis; Odom, Randy; Figliozzi, Robert W.; Chen, Feng; Balish, Matthew; Parmar, Jayesh; Freeman, Robert; Snitzer, Jack; Hsia, S. Victor

    2015-01-01

    SUMMARY The reactivation of dormant alpha-Human Herpes Virus (αHHV) has been attributed to various causes often referred to as stressors. However, no clinical study investigating the relationship between stressors and reactivation exists in humans at this time. Herpes Simplex Virus Type-1 (HSV-1), an important αHHV, was shown to have its gene expression and replication regulated by Thyroid hormone (TH) using molecular biology approaches. Varicella Zoster Virus (VZV) is categorized in αHHV superfamily and shares similar homology with HSV-1. We hypothesize that a history of TH imbalance may be associated with the incidence of shingles (VZV reactivation). This current pilot study, based on a hospital medical claim database, was conducted as a retrospective case-controlled investigation to determine if a putative link between TH imbalance and incidence of shingles is present. An OR of 2.95 with a Chi-square of 51.74 was calculated for the total population diagnosed with TH disruption and shingles. Further analyses indicated that African American males exhibited much higher chance of simultaneous diagnoses. These results showed that a TH imbalance history may affect VZV reactivation at different incidence rates in different races and age groups. PMID:26189668

  1. Influence of thyroid hormone disruption on the incidence of shingles.

    PubMed

    Ajavon, A; Killian, D; Odom, R; Figliozzi, R W; Chen, F; Balish, M; Parmar, J; Freeman, R; Snitzer, J; Hsia, S V

    2015-12-01

    The reactivation of dormant alpha-human herpesvirus (αHHV) has been attributed to various causes often referred to as stressors. However, no clinical study investigating the relationship between stressors and reactivation exists in humans at this time. Herpes simplex virus type-1 (HSV-1), an important αHHV, was shown to have its gene expression and replication regulated by thyroid hormone (TH) using molecular biology approaches. Varicella zoster virus (VZV) is categorized in αHHV superfamily and shares similar homology with HSV-1. We hypothesize that a history of TH imbalance may be associated with the incidence of shingles (VZV reactivation). This current pilot study, based on a hospital medical claims database, was conducted as a retrospective case-controlled investigation to determine if a putative link between TH imbalance and incidence of shingles is present. An odds ratio of 2·95 with a χ 2 value of 51·74 was calculated for the total population diagnosed with TH disruption and shingles. Further analyses indicated that African American males exhibited a much higher chance of simultaneous diagnoses. These results show that a TH imbalance history may affect VZV reactivation at different incidence rates in different races and age groups.

  2. Nitrite-induced alterations in sex steroids and thyroid hormones of Labeo rohita juveniles: effects of dietary vitamin E and L-tryptophan.

    PubMed

    Ciji, A; Sahu, N P; Pal, A K; Akhtar, M S

    2013-10-01

    An experiment was conducted to study the effect of sub-lethal nitrite exposure on sex steroids (testosterone and estradiol), cortisol and thyroid hormones (T3 and T4) of Labeo rohita juveniles. Fishes previously fed with normal or elevated levels of vitamin E (VE) and tryptophan for 60 days were exposed to sub-lethal nitrite for another 45 days with same feeding regime. There were nine treatment groups, viz. VE0TRP0-N, VE0TRP0+N, VE100TRP0-N, VE100TRP0+N, VE100TRP0.75+N, VE100TRP1.5+N, VE150TRP0+N, VE300TRP0+N and VE200TRP1+N. Except the groups VE0TRP0-N and VE100TRP0-N, all other groups were exposed to nitrite. At the end of the 45 days of nitrite exposure, serum samples were assayed for sex steroids, cortisol and thyroid hormones. The serum T3 and T4 levels decreased to the extent of 84.5 and 94.06%, respectively, upon nitrite exposure. Dietary supplementation with additional amounts of VE and tryptophan appears to reduce the decline of the production of T4. The serum testosterone and estradiol decreased 97.31 and 92.86%, respectively, upon nitrite exposure. Supplementation with additional amounts of VE was found to reverse nitrite-induced inhibition of testosterone and estradiol production. Serum cortisol increased upon nitrite exposure and unexposed (VE100-N) group showed lower levels, which were comparable to groups fed with elevated levels of VE. The overall results of the present study revealed that environmental nitrites have a negative impact on steroidogenesis, which can be overcome by dietary supplementation of elevated amounts of VE (minimum of 150 mg VE Kg diet(-1)) and to a lesser extent by tryptophan (only at the level of 1.5% of the diet).

  3. Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts.

    PubMed

    Furey, Nathan B; Vincent, Stephen P; Hinch, Scott G; Welch, David W

    2015-01-01

    Variability in animal migratory behavior is expected to influence fitness, but few empirical examples demonstrating this relationship exist. The initial marine phase in the migration of juvenile salmon smolts has been identified as a potentially critical life history stage to overall population productivity, yet how fine-scale migration routes may influence survival are unknown. Large-scale acoustic telemetry studies have estimated survival rates of outmigrant Pacific salmon smolts through the Strait of Georgia (SOG) along the British Columbian coastline to the Pacific Ocean, but these data have not been used to identify and characterize fine-scale movements. Data collected on over 850 sockeye salmon (Oncorhynchus nerka) and steelhead (Oncorhynchus mykiss) smolts detected at an array in the Strait of Georgia in 2004-2008 and 2010-2013 were analyzed to characterize migration routes and link movements to subsequent survival at an array 250 km further along the marine migration pathway. Both species exhibited disproportionate use of the most eastern route in the Strait of Georgia (Malaspina Strait). While many smolts moved across the northern Strait of Georgia acoustic array with no indication of long-term milling or large-scale east-to-west movements, large proportions (20-40% of sockeye and 30-50% of steelhead) exhibited a different behavior, apparently moving in a westward or counterclockwise pattern. Variability in migratory behavior for both species was linked to subsequent survival through the Strait of Georgia. Survival for both species was influenced by initial east-to-west location, and sockeye were further influenced by migration timing and duration of time spent near the northern Strait of Georgia array. Westward movements result in a net transport of smolts from Malaspina Strait to the Strait of Georgia, particularly for steelhead. Counterclockwise movements may be due to the currents in this area during the time of outmigration, and the higher proportion

  4. Variability in Migration Routes Influences Early Marine Survival of Juvenile Salmon Smolts

    PubMed Central

    Furey, Nathan B.; Vincent, Stephen P.; Hinch, Scott G.; Welch, David W.

    2015-01-01

    Variability in animal migratory behavior is expected to influence fitness, but few empirical examples demonstrating this relationship exist. The initial marine phase in the migration of juvenile salmon smolts has been identified as a potentially critical life history stage to overall population productivity, yet how fine-scale migration routes may influence survival are unknown. Large-scale acoustic telemetry studies have estimated survival rates of outmigrant Pacific salmon smolts through the Strait of Georgia (SOG) along the British Columbian coastline to the Pacific Ocean, but these data have not been used to identify and characterize fine-scale movements. Data collected on over 850 sockeye salmon (Oncorhynchus nerka) and steelhead (Oncorhynchus mykiss) smolts detected at an array in the Strait of Georgia in 2004–2008 and 2010–2013 were analyzed to characterize migration routes and link movements to subsequent survival at an array 250 km further along the marine migration pathway. Both species exhibited disproportionate use of the most eastern route in the Strait of Georgia (Malaspina Strait). While many smolts moved across the northern Strait of Georgia acoustic array with no indication of long-term milling or large-scale east-to-west movements, large proportions (20–40% of sockeye and 30–50% of steelhead) exhibited a different behavior, apparently moving in a westward or counterclockwise pattern. Variability in migratory behavior for both species was linked to subsequent survival through the Strait of Georgia. Survival for both species was influenced by initial east-to-west location, and sockeye were further influenced by migration timing and duration of time spent near the northern Strait of Georgia array. Westward movements result in a net transport of smolts from Malaspina Strait to the Strait of Georgia, particularly for steelhead. Counterclockwise movements may be due to the currents in this area during the time of outmigration, and the higher

  5. Krüppel homolog 1 and E93 mediate Juvenile hormone regulation of metamorphosis in the common bed bug, Cimex lectularius

    PubMed Central

    Gujar, Hemant; Palli, Subba Reddy

    2016-01-01

    The common bed bug is an obligate hematophagous parasite of humans. We studied the regulation of molting and metamorphosis in bed bugs with a goal to identify key players involved. qRT-PCR studies on the expression of genes known to be involved in molting and metamorphosis showed high levels of Krüppel homolog 1 [Kr-h1, a transcription factor that plays key roles in juvenile hormone (JH) action] mRNA in the penultimate nymphal stage (N4). However, low levels of Kr-h1 mRNA were detected in the fifth and last nymphal stage (N5). Knockdown of Kr-h1 in N4 resulted in a precocious development of adult structures. Kr-h1 maintains the immature stage by suppressing E93 (early ecdysone response gene) in N4. E93 expression increases during the N5 in the absence of Kr-h1 and promotes the development of adult structures. Knockdown of E93 in N5 results in the formation of supernumerary nymphs. The role of JH in the suppression of adult structures through interaction with Kr-h1 and E93 was also studied by the topical application of JH analog, methoprene, to N5. Methoprene induced Kr-h1 and suppressed E93 and induced formation of the supernumerary nymph. These data show interactions between Kr-h1, E93 and JH in the regulation of metamorphosis in the bed bugs. PMID:27185064

  6. An isoform of Taiman that contains a PRD-repeat motif is indispensable for transducing the vitellogenic juvenile hormone signal in Locusta migratoria.

    PubMed

    Wang, Zhiming; Yang, Libin; Song, Jiasheng; Kang, Le; Zhou, Shutang

    2017-03-01

    Taiman (Tai) has been recently identified as the dimerizing partner of juvenile hormone (JH) receptor, Methoprene-tolerant (Met). However, the role of Tai isoforms in transducing vitellogenic signal of JH has not been determined. In this study, we show that the migratory locust Locusta migratoria has two Tai isoforms, which differ in an INDEL-1 domain with the PRD-repeat motif rich in histidine and proline at the C-terminus. Tai-A with the INDEL-1 is expressed at levels about 50-fold higher than Tai-B without the INDEL-1 in the fat body of vitellogenic adult females. Knockdown of Tai-A but not Tai-B results in a substantial reduction of vitellogenin expression in the fat body accompanied by the arrest of ovarian development and oocyte maturation, similar to that caused by depletion of both Tai isoforms. Either Tai-A or Tai-B combined with Met can induce target gene transcription in response to JH, but Tai-A appears to mediate a significantly higher transactivation. Our data suggest that the INDEL-1 domain plays a critical role in Tai function during reproduction as Tai-A appears be more active than Tai-B in transducing the vitellogenic JH signal in L. migratoria.

  7. The juvenile hormone (JH) epoxide hydrolase gene in the honey bee (Apis mellifera) genome encodes a protein which has negligible participation in JH degradation.

    PubMed

    Mackert, Aline; Hartfelder, Klaus; Bitondi, Márcia Maria Gentile; Simões, Zilá Luz Paulino

    2010-09-01

    Epoxide hydrolases are multifunctional enzymes that are best known in insects for their role in juvenile hormone (JH) degradation. Enzymes involved in JH catabolism can play major roles during metamorphosis and reproduction, such as the JH epoxide hydrolase (JHEH), which degrades JH through hydration of the epoxide moiety to form JH diol, and JH esterase (JHE), which hydrolyzes the methyl ester to produce JH acid. In the honey bee, JH has been co-opted for additional functions, mainly in caste differentiation and in age-related behavioral development of workers, where the activity of both enzymes could be important for JH titer regulation. Similarity searches for jheh candidate genes in the honey bee genome revealed a single Amjheh gene. Sequence analysis, quantification of Amjheh transcript levels and Western blot assays using an AmJHEH-specific antibody generated during this study revealed that the AmJHEH found in the fat body shares features with the microsomal JHEHs from several insect species. Using a partition assay we demonstrated that AmJHEH has a negligible role in JH degradation, which, in the honey bee, is thus performed primarily by JHE. High AmJHEH levels in larvae and adults were related to the ingestion of high loads of lipids, suggesting that AmJHEH has a role in dietary lipid catabolism.

  8. Proteome analysis of male accessory gland secretions in oriental fruit flies reveals juvenile hormone-binding protein, suggesting impact on female reproduction.

    PubMed

    Wei, Dong; Li, Hui-Min; Tian, Chuan-Bei; Smagghe, Guy; Jia, Fu-Xian; Jiang, Hong-Bo; Dou, Wei; Wang, Jin-Jun

    2015-11-19

    In insects, the accessory gland proteins (Acps) secreted by male accessory glands (MAGs) account for the majority of seminal fluids proteins. Mixed with sperm, they are transferred to the female at mating and so impact reproduction. In this project, we identified 2,927 proteins in the MAG secretions of the oriental fruit fly Bactrocera dorsalis, an important agricultural pest worldwide, using LC-MS analysis, and all sequences containing open reading frames were analyzed using signalP. In total, 90 Acps were identified. About one third (26) of these 90 Acps had a specific functional description, while the other two thirds (64) had no functional description including dozens of new classes of proteins. Hence, several of these novel Acps were abundant in the MAG secretions, and we confirmed their MAG-specific expression by qPCR. Finally and interestingly, one of these novel proteins was functionally predicted as juvenile hormone-binding protein, suggesting the impact of Acps with reproductive events in the female. Our results will aid in the development of an experimental method to identify Acps in insects, and in turn this information with new Acps in B. dorsalis will pave the way of further exploration their function in reproduction and potential development as new insecticide targets.

  9. Proteome analysis of male accessory gland secretions in oriental fruit flies reveals juvenile hormone-binding protein, suggesting impact on female reproduction

    PubMed Central

    Wei, Dong; Li, Hui-Min; Tian, Chuan-Bei; Smagghe, Guy; Jia, Fu-Xian; Jiang, Hong-Bo; Dou, Wei; Wang, Jin-Jun

    2015-01-01

    In insects, the accessory gland proteins (Acps) secreted by male accessory glands (MAGs) account for the majority of seminal fluids proteins. Mixed with sperm, they are transferred to the female at mating and so impact reproduction. In this project, we identified 2,927 proteins in the MAG secretions of the oriental fruit fly Bactrocera dorsalis, an important agricultural pest worldwide, using LC-MS analysis, and all sequences containing open reading frames were analyzed using signalP. In total, 90 Acps were identified. About one third (26) of these 90 Acps had a specific functional description, while the other two thirds (64) had no functional description including dozens of new classes of proteins. Hence, several of these novel Acps were abundant in the MAG secretions, and we confirmed their MAG-specific expression by qPCR. Finally and interestingly, one of these novel proteins was functionally predicted as juvenile hormone-binding protein, suggesting the impact of Acps with reproductive events in the female. Our results will aid in the development of an experimental method to identify Acps in insects, and in turn this information with new Acps in B. dorsalis will pave the way of further exploration their function in reproduction and potential development as new insecticide targets. PMID:26582577

  10. Krüppel homolog 1 and E93 mediate Juvenile hormone regulation of metamorphosis in the common bed bug, Cimex lectularius.

    PubMed

    Gujar, Hemant; Palli, Subba Reddy

    2016-05-17

    The common bed bug is an obligate hematophagous parasite of humans. We studied the regulation of molting and metamorphosis in bed bugs with a goal to identify key players involved. qRT-PCR studies on the expression of genes known to be involved in molting and metamorphosis showed high levels of Krüppel homolog 1 [Kr-h1, a transcription factor that plays key roles in juvenile hormone (JH) action] mRNA in the penultimate nymphal stage (N4). However, low levels of Kr-h1 mRNA were detected in the fifth and last nymphal stage (N5). Knockdown of Kr-h1 in N4 resulted in a precocious development of adult structures. Kr-h1 maintains the immature stage by suppressing E93 (early ecdysone response gene) in N4. E93 expression increases during the N5 in the absence of Kr-h1 and promotes the development of adult structures. Knockdown of E93 in N5 results in the formation of supernumerary nymphs. The role of JH in the suppression of adult structures through interaction with Kr-h1 and E93 was also studied by the topical application of JH analog, methoprene, to N5. Methoprene induced Kr-h1 and suppressed E93 and induced formation of the supernumerary nymph. These data show interactions between Kr-h1, E93 and JH in the regulation of metamorphosis in the bed bugs.

  11. Juvenile hormone enhances aversive learning performance in 2-day old worker honey bees while reducing their attraction to queen mandibular pheromone.

    PubMed

    McQuillan, H James; Nakagawa, Shinichi; Mercer, Alison R

    2014-01-01

    Previous studies have shown that exposing young worker bees (Apis mellifera) to queen mandibular pheromone (QMP) reduces their aversive learning performance, while enhancing their attraction to QMP. As QMP has been found to reduce the rate of juvenile hormone (JH) synthesis in worker bees, we examined whether aversive learning in 2-day old workers exposed to QMP from the time of adult emergence could be improved by injecting JH (10 µg in a 2 µl volume) into the haemolymph. We examined in addition, the effects of JH treatment on worker attraction to QMP, and on the levels of expression of amine receptor genes in the antennae, as well as in the mushroom bodies of the brain. We found that memory acquisition and 1-hour memory recall were enhanced by JH. In contrast, JH treatment reduced the bees' attraction towards a synthetic strip impregnated with QMP (Bee Boost). Levels of expression of the dopamine receptor gene Amdop1 were significantly lower in the mushroom bodies of JH-treated bees than in bees treated with vehicle alone (acetone diluted with bee ringer). Expression of the octopamine receptor gene, Amoa1, in this brain region was also affected by JH treatment, and in the antennae, Amoa1 transcript levels were significantly lower in JH-treated bees compared to controls. The results of this study suggest that QMP's effects on JH synthesis may contribute to reducing aversive learning performance and enhancing attraction to QMP in young worker bees.

  12. Brain sex differences and the organisation of juvenile social play behaviour.

    PubMed

    Auger, A P; Olesen, K M

    2009-06-01

    Juvenile social play behaviour is one of the earliest forms of non-mother directed social behaviour in rodents. Juvenile social play behaviour is sexually dimorphic, with males exhibiting higher levels compared to females, making it a useful model to study both social development and sexual differentiation of the brain. As with most sexually dimorphic behaviour, juvenile play behaviour is organised by neonatal steroid hormone exposure. The developmental organisation of juvenile play behaviour also appears to be influenced by the early maternal environment. This review will focus briefly on why and how rats play, some brain regions controlling play behaviour, and how neurotransmitters and the social environment converge within the developing brain to influence sexual differentiation of juvenile play behaviour.

  13. Repeated, Intermittent Social Defeat across the Entire Juvenile Period Resulted in Behavioral, Physiological, Hormonal, Immunological, and Neurochemical Alterations in Young Adult Male Golden Hamsters.

    PubMed

    Yu, Wei-Chun; Liu, Ching-Yi; Lai, Wen-Sung

    2016-01-01

    The developing brain is vulnerable to social defeat during the juvenile period. As complements of human studies, animal models of social defeat provide a straightforward approach to investigating the functional and neurobiological consequences of social defeats. Taking advantage of agonist behavior and social defeat in male golden hamster, a set of 6 experiments was conducted to investigate the consequences at multiple levels in young adulthood resulting from repeated, intermittent social defeats or "social threats" across the entire juvenile period. Male hamsters at postnatal day 28 (P28) were randomly assigned to either the social defeat, "social threat", or arena control group, and they correspondingly received a series of nine social interaction trials (i.e., either social defeat, "social threat", or arena control conditions) from P33 to P66. At the behavioral level (Experiment 1), we found that repeated social defeats (but not "social threats") significantly impacted locomotor activity in the familiar context and social interaction in the familiar/unfamiliar social contexts. At the physiological and hormonal levels (Experiments 2 and 3), repeated social defeat significantly enhanced the cortisol and norepinephrine concentrations in blood. Enlargement of the spleen was also found in the social defeat and "social threat" groups. At the immunological level (Experiment 4), the social defeat group showed lower levels of pro-inflammatory cytokines in the hypothalamus and hippocampus but higher concentration of IL-6 in the striatum compared to the other two groups. At the neurochemical level (Experiment 5), the socially defeated hamsters mainly displayed reductions of dopamine, dopamine metabolites, and 5-HT levels in the striatum and decreased level of 5-HT in the hippocampus. In Experiment 6, an increase in the spine density of hippocampal CA1 pyramidal neurons was specifically observed in the "social threat" group. Collectively, our findings indicate that repeated

  14. Repeated, Intermittent Social Defeat across the Entire Juvenile Period Resulted in Behavioral, Physiological, Hormonal, Immunological, and Neurochemical Alterations in Young Adult Male Golden Hamsters

    PubMed Central

    Yu, Wei-Chun; Liu, Ching-Yi; Lai, Wen-Sung

    2016-01-01

    The developing brain is vulnerable to social defeat during the juvenile period. As complements of human studies, animal models of social defeat provide a straightforward approach to investigating the functional and neurobiological consequences of social defeats. Taking advantage of agonist behavior and social defeat in male golden hamster, a set of 6 experiments was conducted to investigate the consequences at multiple levels in young adulthood resulting from repeated, intermittent social defeats or “social threats” across the entire juvenile period. Male hamsters at postnatal day 28 (P28) were randomly assigned to either the social defeat, “social threat”, or arena control group, and they correspondingly received a series of nine social interaction trials (i.e., either social defeat, “social threat”, or arena control conditions) from P33 to P66. At the behavioral level (Experiment 1), we found that repeated social defeats (but not “social threats”) significantly impacted locomotor activity in the familiar context and social interaction in the familiar/unfamiliar social contexts. At the physiological and hormonal levels (Experiments 2 and 3), repeated social defeat significantly enhanced the cortisol and norepinephrine concentrations in blood. Enlargement of the spleen was also found in the social defeat and “social threat” groups. At the immunological level (Experiment 4), the social defeat group showed lower levels of pro-inflammatory cytokines in the hypothalamus and hippocampus but higher concentration of IL-6 in the striatum compared to the other two groups. At the neurochemical level (Experiment 5), the socially defeated hamsters mainly displayed reductions of dopamine, dopamine metabolites, and 5-HT levels in the striatum and decreased level of 5-HT in the hippocampus. In Experiment 6, an increase in the spine density of hippocampal CA1 pyramidal neurons was specifically observed in the “social threat” group. Collectively, our

  15. Knockdown of the juvenile hormone receptor gene inhibits soldier-specific morphogenesis in the damp-wood termite Zootermopsis nevadensis (Isoptera: Archotermopsidae).

    PubMed

    Masuoka, Yudai; Yaguchi, Hajime; Suzuki, Ryutaro; Maekawa, Kiyoto

    2015-09-01

    The Methoprene-tolerant (Met) protein has been established as a juvenile hormone (JH) receptor. Knockdown of the Met gene caused precocious metamorphosis and suppression of ovarian development. However, the function of Met in caste development of social insects is unclear. In termites, JH acts as a central factor for caste development, especially for soldier differentiation, which involves two molts from workers via a presoldier stage. Increased JH titer in workers is needed for the presoldier molt, and the high JH titer is maintained throughout the presoldier period. Although presoldiers have the fundamental morphological features of soldiers, the nature of the cuticle is completely different from that of soldiers. We expected that JH signals via Met are involved in soldier-specific morphogenesis of the head and mandibles during soldier differentiation, especially in the presoldier period, in natural conditions. To test this hypothesis, we focused on soldier differentiation in an incipient colony of the damp-wood termite Zootermopsis nevadensis. Met homolog (ZnMet) expression in heads increased just after the presoldier molt. This high expression was reduced by ZnMet double stranded (dsRNA) injection before the presoldier molt. Although this treatment did not cause any morphological changes in presoldiers, it caused strong effects on soldiers, their mandibles being significantly shorter and head capsules smaller than those of control soldiers. Injection of ZnMet dsRNA throughout the presoldier stage did not affect the formation of soldier morphology, including cuticle formation. These results suggested that the rapid increase in ZnMet expression and subsequent activation of JH signaling just after the presoldier molt are needed for the formation of soldier-specific weapons. Therefore, besides its established role in insect metamorphosis, the JH receptor signaling also underlies soldier development in termites.

  16. Comparative metabolism of branched-chain amino acids to precursors of juvenile hormone biogenesis in corpora allata of lepidopterous versus nonlepidopterous insects

    SciTech Connect

    Brindle, P.A.; Schooley, D.A.; Tsai, L.W.; Baker, F.C.

    1988-08-05

    Comparative studies were performed on the role of branched-chain amino acids (BCAA) in juvenile hormone (JH) biosynthesis using several lepidopterous and nonlepidopterous insects. Corpora cardiaca-corpora allata complexes (CC-CA, the corpora allata being the organ of JH biogenesis) were maintained in culture medium containing a uniformly /sup 14/C-labeled BCAA, together with (methyl-/sup 3/H)methionine as mass marker for JH quantification. BCAA catabolism was quantified by directly analyzing the medium for the presence of /sup 14/C-labeled propionate and/or acetate, while JHs were extracted, purified by liquid chromatography, and subjected to double-label liquid scintillation counting. Our results indicate that active BCAA catabolism occurs within the CC-CA of lepidopterans, and this efficiently provides propionyl-CoA (from isoleucine or valine) for the biosynthesis of the ethyl branches of JH I and II. Acetyl-CoA, formed from isoleucine or leucine catabolism, is also utilized by lepidopteran CC-CA for biosynthesizing JH III and the acetate-derived portions of the ethyl-branched JHs. In contrast, CC-CA of nonlepidopterans fail to catabolize BCAA. Consequently, exogenous isoleucine or leucine does not serve as a carbon source for the biosynthesis of JH III by these glands, and no propionyl-CoA is produced for genesis of ethyl-branched JHs. This is the first observation of a tissue-specific metabolic difference which in part explains why these novel homosesquiterpenoids exist in lepidopterans, but not in nonlepidopterans.

  17. Juvenile hormone and methyl farnesoate production in cockroach embryos in relation to dorsal closure and the reproductive modes of different species of cockroaches.

    PubMed

    Li, Xinyi

    2007-12-01

    Juvenile hormone (JH), produced by the corpora allata (CA), is first detectable after dorsal closure, a conspicuous event in embryogenesis. The present research found that the timing of dorsal closure was consistently at about 45% of the total embryonic development time across most of the oviparous and ovoviviparous cockroach species examined. These included the ovoviviparous cockroaches Blaberus discoidalis, Byrsotria fumigata, Rhyparobia maderae, Nauphoeta cinerea, Phoetalia pallida, Schultesia lampyridiformis, and Panchlora nivea, as well as the oviparous cockroaches Blatta orientalis, Periplaneta americana, Eurycotis floridana, and Supella longipalpa. However, the only known viviparous cockroach Diploptera punctata completed dorsal closure at 20.8% of embryo development time. Methyl farnesoate (MF), the immediate precursor of JH III, is considered a functional molecule in crustaceans; however, in insects its function is still unclear. To understand the role of JH and MF in cockroach embryos, I compared JH and MF biosynthesis and release in several cockroach species of known phylogenetic relationships. Using a radiochemical assay, the present research showed that cockroach embryos representing all three reproductive modes produced and released both JH and MF, as previously shown for B. germanica, N. cinerea, and D. punctata. Members of a pair of embryonic CA from B. discoidalis, B. fumigata, R. maderae, and D. punctata were incubated with and without farnesol. MF accumulated in large amounts only in CA of R. maderae in the presence of farnesol, which indicates that control of the last step of biosynthesis of JH, conversion of MF into JH by MF epoxidase, is probably a rate-limiting step in this species.

  18. Mosquito-specific microRNA-1890 targets the juvenile hormone-regulated serine protease JHA15 in the female mosquito gut

    PubMed Central

    Lucas, Keira J; Zhao, Bo; Roy, Sourav; Gervaise, Amanda L; Raikhel, Alexander S

    2015-01-01

    Females of the hematophagous mosquito species require a vertebrate blood meal to supply amino acids and other nutrients necessary for egg development, serving as the driving force for the spread of many vector-borne diseases in humans. Blood digestion utilizes both early and late phase serine proteases (SPs) that are differentially regulated at the transcriptional and post-transcriptional level. To uncover the regulatory complexity of SPs in the female mosquito midgut, we investigated involvement of miRNAs in regulating the juvenile hormone (JH)-controlled chymotrypsin-like SP, JHA15. We identified regulatory regions complementary to the mosquito-specific miRNA, miR-1890, within the 3′ UTR of JHA15 mRNA. The level of the JHA15 transcript is highest post eclosion and drastically declines post blood meal (PBM), exhibiting an opposite trend to miR-1890 that peaks at 24 h PBM. Depletion of miR-1890 results in defects in blood digestion, ovary development and egg deposition. JHA15 mRNA and protein levels are elevated in female mosquitoes with miR-1890 inhibition. JHA15 RNA interference in the miR-1890 depletion background alleviates miR-1890 depletion phenotypes. The miR-1890 gene is activated by the 20-hydroxyecdysone pathway that involves the ecdysone receptor and the early genes, E74B and Broad Z2. Our study suggests that miR-1890 controls JHA15 mRNA stability in a stage- and tissue- specific manner. PMID:26488481

  19. Juvenile hormone facilitates the antagonism between adult reproduction and diapause through the methoprene-tolerant gene in the female Colaphellus bowringi.

    PubMed

    Liu, Wen; Li, Yi; Zhu, Li; Zhu, Fen; Lei, Chao-Liang; Wang, Xiao-Ping

    2016-07-01

    In insects, the process whereby juvenile hormone (JH) regulates short-day (SD)-induced reproductive diapause has been previously investigated. However, we still do not understand the mechanism by which JH regulates long-day (LD)-induced reproductive diapause. In this study, we use a cabbage beetle, Colaphellus bowringi, which is a serious pest of cruciferous vegetables in Asia capable of entering reproductive diapause under LD conditions, as a model to test whether JH regulates female reproductive diapause similar to the mechanism of SD-induced diapause. Our results showed that the JH analog (JHA) methoprene significantly induced ovarian development but inhibited lipid accumulation of diapause-destined adults. Meanwhile, the transcripts of the vitellogenin (Vg) genes were upregulated, whereas the expression of the fat synthesis and stress tolerance genes were downregulated. RNA interference of the JH candidate receptor gene methoprene-tolerant (Met) blocked JH-induced ovarian development and Vg transcription, suggesting a positive regulatory function for JH-Met signaling in reproduction. Furthermore, under reproduction-inducing conditions, Met depletion promoted a diapause-like phenotype, including arrested ovarian development and increased lipid storage, and stimulated the expression of diapause-related genes involved in lipid synthesis and stress tolerance, suggesting JH-Met signaling plays an important role in the inhibition of diapause. Accordingly, our data indicate that JH acts through Met to facilitate development of the reproductive system by upregulating Vg expression while inhibiting diapause by suppressing lipid synthesis and stress tolerance in the cabbage beetle. Combined with previous studies in SD-induced reproductive diapause, we conclude that JH may regulate female reproductive diapause using a conserved Met-dependent pathway, regardless of the length of the photoperiod inducing diapause in insects.

  20. Linear growth in children suffering from juvenile idiopathic arthritis requiring steroid therapy: natural history and effects of growth hormone treatment on linear growth.

    PubMed

    Simon, D; Lucidarme, N; Prieur, A M; Ruiz, J C; Czernichow, P

    2001-01-01

    We assessed linear growth and final height retrospectively in a group of 24 patients suffering from juvenile idiopathic arthritis (JIA) during childhood who had received steroid therapy. In these patients, there was a significant loss of height of more than 2 standard deviations during the first years of the disease, which correlated positively with the duration of prednisone therapy. After remission of the disease and discontinuation of prednisone treatment, 70% of the patients achieved catch-up growth, although 30% showed a persistent loss of height. Their mean final height was strongly correlated with their mean height at the end of steroid therapy and was significantly different between the group of patients with catch-up growth and the group without catch-up growth. This pattern of growth observed in patients with JIA should help us to define strategies of growth hormone (GH) treatment in these patients in order to improve their final height. We have previously reported the beneficial effects on growth and body composition of 1 year of GH treatment in a group of 14 growth-retarded patients suffering from JIA who received glucocorticoid therapy. These patients (n = 13) were treated again with GH at the same dosage (0.46 mg/kg/week [0.07 mg/kg/day]) for another 3-year period. GH treatment markedly increased growth velocity in these patients, but had a minor effect on height SDS, suggesting that these children will remain short when adults. Starting GH therapy in these patients earlier after the onset of the disease may prevent growth deterioration and metabolic complications induced by chronic inflammation and long-term steroid therapy.

  1. Green tea proanthocyanidins cause impairment of hormone-regulated larval development and reproductive fitness via repression of juvenile hormone acid methyltransferase, insulin-like peptide and cytochrome P450 genes in Anopheles gambiae sensu stricto

    PubMed Central

    Nyanjom, Steven G.; Mutunga, James M.; Njeru, Sospeter N.; Bargul, Joel L.

    2017-01-01

    Successful optimization of plant-derived compounds into control of nuisance insects would benefit from scientifically validated targets. However, the close association between the genotypic responses and physiological toxicity effects mediated by these compounds remains underexplored. In this study, we evaluated the sublethal dose effects of proanthocyanidins (PAs) sourced from green tea (Camellia sinensis) on life history traits of Anopheles gambiae (sensu stricto) mosquitoes with an aim to unravel the probable molecular targets. Based on the induced phenotypic effects, genes selected for study targeted juvenile hormone (JH) biosynthesis, signal transduction, oxidative stress response and xenobiotic detoxification in addition to vitellogenesis in females. Our findings suggest that chronic exposure of larval stages (L3/L4) to sublethal dose of 5 ppm dramatically extended larval developmental period for up to 12 days, slowed down pupation rates, induced abnormal larval-pupal intermediates and caused 100% inhibition of adult emergence. Further, females exhibited significant interference of fecundity and egg hatchability relative to controls (p < 0.001). Using reverse transcription quantitative polymerase chain reaction (RT-qPCR), our findings show that PA-treated larvae exhibited significant repression of AgamJHAMT (p < 0.001), AgamILP1 (p < 0.001) and AgamCYP6M2 (p < 0.001) with up-regulation of Hsp70 (p < 0.001). Females exposed as larvae demonstrated down-regulation of AgamVg (p = 0.03), AgamILP1 (p = 0.009), AgamCYP6M2 (p = 0.05) and AgamJHAMT (p = 0.02). Our findings support that C. sinensis proanthocyanidins affect important vectorial capacity components such as mosquito survival rates and reproductive fitness thus could be potentially used for controlling populations of malaria vectors. PMID:28301607

  2. Green tea proanthocyanidins cause impairment of hormone-regulated larval development and reproductive fitness via repression of juvenile hormone acid methyltransferase, insulin-like peptide and cytochrome P450 genes in Anopheles gambiae sensu stricto.

    PubMed

    Muema, Jackson M; Nyanjom, Steven G; Mutunga, James M; Njeru, Sospeter N; Bargul, Joel L

    2017-01-01

    Successful optimization of plant-derived compounds into control of nuisance insects would benefit from scientifically validated targets. However, the close association between the genotypic responses and physiological toxicity effects mediated by these compounds remains underexplored. In this study, we evaluated the sublethal dose effects of proanthocyanidins (PAs) sourced from green tea (Camellia sinensis) on life history traits of Anopheles gambiae (sensu stricto) mosquitoes with an aim to unravel the probable molecular targets. Based on the induced phenotypic effects, genes selected for study targeted juvenile hormone (JH) biosynthesis, signal transduction, oxidative stress response and xenobiotic detoxification in addition to vitellogenesis in females. Our findings suggest that chronic exposure of larval stages (L3/L4) to sublethal dose of 5 ppm dramatically extended larval developmental period for up to 12 days, slowed down pupation rates, induced abnormal larval-pupal intermediates and caused 100% inhibition of adult emergence. Further, females exhibited significant interference of fecundity and egg hatchability relative to controls (p < 0.001). Using reverse transcription quantitative polymerase chain reaction (RT-qPCR), our findings show that PA-treated larvae exhibited significant repression of AgamJHAMT (p < 0.001), AgamILP1 (p < 0.001) and AgamCYP6M2 (p < 0.001) with up-regulation of Hsp70 (p < 0.001). Females exposed as larvae demonstrated down-regulation of AgamVg (p = 0.03), AgamILP1 (p = 0.009), AgamCYP6M2 (p = 0.05) and AgamJHAMT (p = 0.02). Our findings support that C. sinensis proanthocyanidins affect important vectorial capacity components such as mosquito survival rates and reproductive fitness thus could be potentially used for controlling populations of malaria vectors.

  3. The influence of sex hormones on seizures in dogs and humans.

    PubMed

    Van Meervenne, Sofie A E; Volk, Holger A; Matiasek, Kaspar; Van Ham, Luc M L

    2014-07-01

    Epilepsy is the most common chronic neurological disorder in both humans and dogs. The effect of sex hormones on seizures is well documented in human medicine. Catamenial epilepsy is defined as an increase in frequency and severity of seizures during certain periods of the menstrual cycle. Oestradiol increases seizure activity and progesterone is believed to exhibit a protective effect. The role of androgens is controversial and there is a lack of research focusing on androgens and epilepsy. Indeed, little is known about the influence of sex hormones on epilepsy in dogs. Sterilisation is believed to improve seizure control, but no systematic research has been conducted in this field. This review provides an overview of the current literature on the influence of sex hormones on seizures in humans. The literature on idiopathic epilepsy in dogs was assessed to identify potential risk factors related to sex and sterilisation status. In general, there appears to be an over-representation of male dogs with idiopathic epilepsy but no explanation for this difference in prevalence between sexes has been reported. In addition, no reliable conclusions can be drawn on the effect of sterilisation due to the lack of focused research and robust scientific evidence.

  4. Influence of externally attached transmitters on the swimming performance of juvenile white sturgeon

    USGS Publications Warehouse

    Counihan, T.D.; Frost, C.N.

    1999-01-01

    We measured the critical swimming speed of juvenile white sturgeons Acipenser transmontanus equipped with externally attached dummy ultrasonic transmitters and of untagged control fish in the laboratory. White sturgeons ranging from 31.9 to 37.0 cm fork length were subjected to one of three treatments: control (handled but not tagged), tag attached below the dorsal fin, and tag attached with the anterior insertion point between the fourth and fifth dorsal scutes. Although transmitters were of recommended weight, we found that the swimming performance of tagged white sturgeons was significantly less than that of untagged control fish. Swimming performance of tagged fish was not differentially affected by tag location. Our results suggest that data from ultrasonic telemetry studies of externally tagged juvenile white sturgeons should be interpreted with caution due to the reduced swimming performance caused by external transmitters.

  5. Influence of externally attached trasmitters on the swimming performance of juvenile white sturgeon

    USGS Publications Warehouse

    Counihan, T.D.; Frost, C.N.

    1999-01-01

    We measured the critical swimming speed of juvenile white sturgeons Acipenser transmontanus equipped with externally attached dummy ultrasonic transmitters and of untagged control fish in the laboratory. White sturgeons ranging from 31.9 to 37.0 cm fork length were subjected to one of three treatments: Control (handled but not tagged), tag attached below the dorsal fin, and tag attached with the anterior insertion point between the fourth and fifth dorsal scutes. Although transmitters were of recommended weight, we found that the swimming performance of tagged white sturgeons was significantly less than that of untagged control fish. Swimming performance of tagged fish was not differentially affected by tag location. Our results suggest that data from ultrasonic telemetry studies of externally tagged juvenile white sturgeons should be interpreted with caution due to the reduced swimming performance caused by external transmitters.

  6. Climate-driven coral reorganisation influences aggressive behaviour in juvenile coral-reef fishes

    NASA Astrophysics Data System (ADS)

    Kok, Judith E.; Graham, Nicholas A. J.; Hoogenboom, Mia O.

    2016-06-01

    Globally, habitat degradation is altering the abundance and diversity of species in a variety of ecosystems. This study aimed to determine how habitat degradation, in terms of changing coral composition under climate change, affected abundance, species richness and aggressive behaviour of juveniles of three damselfishes ( Pomacentrus moluccensis, P. amboinensis and Dischistodus perspicillatus, in order of decreasing reliance on coral). Patch reefs were constructed to simulate two types of reefs: present-day reefs that are vulnerable to climate-induced coral bleaching, and reefs with more bleaching-robust coral taxa, thereby simulating the likely future of coral reefs under a warming climate. Fish communities were allowed to establish naturally on the reefs during the summer recruitment period. Climate-robust reefs had lower total species richness of coral-reef fishes than climate-vulnerable reefs, but total fish abundance was not significantly different between reef types (pooled across all species and life-history stages). The nature of aggressive interactions, measured as the number of aggressive chases, varied according to coral composition; on climate-robust reefs, juveniles used the substratum less often to avoid aggression from competitors, and interspecific aggression became relatively more frequent than intraspecific aggression for juveniles of the coral-obligate P. moluccensis. This study highlights the importance of coral composition as a determinant of behaviour and diversity of coral-reef fishes.

  7. The influence of androgenic steroid hormones on female aggression in 'atypical' mammals.

    PubMed

    French, Jeffrey A; Mustoe, Aaryn C; Cavanaugh, Jon; Birnie, Andrew K

    2013-01-01

    Dimorphism on dominance and agonistic behaviour in mammals tends to be strongly biased toward males. In this review, we focus on a select few species of mammals in which females are as or more aggressive than males, and/or are dominant to males, and explore the role of androgenic hormones in mediating this important difference. While the data are not as clear-cut as those published on traditional laboratory mammals, our review highlights important endocrine substrates for both organizational and activational influences of steroids on female aggressive behaviour. We highlight areas in which further observations and experiments are crucial, especially the potential facilitative effects of androgens on female aggression. Finally, new and innovative techniques, including molecular genetics and receptor pharmacology, portend important insights into the ways in which androgenic hormones regulate aggressive behaviour in 'atypical' female mammals.

  8. How type of parturition and health status influence hormonal and metabolic profiles in newborn foals.

    PubMed

    Panzani, S; Comin, A; Galeati, G; Romano, G; Villani, M; Faustini, M; Veronesi, M C

    2012-04-01

    Thyroid hormones, insulin growth factor I (IGF-I) and non-esterified fatty acids (NEFA) represent important hormonal and metabolic factors associated with perinatal growth and maturation. Their action could be influenced by the type of parturition and the health status of the foal and therefore the aim of this work is to evaluate their plasma concentrations in newborn foals during the first 2 wks of life. Three groups of subjects were enrolled: 15 healthy foals born by spontaneous parturition, 24 healthy foals born by induced parturition and 26 pathologic foals. From each of the healthy foals, blood was collected at 10, 20 and 30 minutes, 3 and 12 hours from birth, daily from Day 1 to Day 7, and at Day 10 and 14 of life. In pathologic foals samples were collected twice a day from the day of admission at the hospital until the day of discharge or death. Thyroid hormones (T3 and T4) and IGF-I were analyzed by radioimmunoassay and NEFA by enzymatic-colorimetric methods. In all the three groups a declining trend of T3 and T4 plasma concentrations was detectable, with lower levels in the pathologic group compared to healthy foals. Spontaneous foals showed higher levels of T3 at 7 d compared to induced foals, while T4 levels were higher in spontaneous vs. induced foals before 6 h of life, at three and seven days. IGF-I showed increasing plasma concentrations in all three considered groups. No differences were found between healthy and pathologic foals. NEFA in spontaneous and induced healthy foals showed a declining trend with higher levels during the first hours of life. Pathologic foals presented higher levels compared to spontaneous foals only at 24 h and 10 d. These data suggest that the type of foaling could influence the reference ranges for thyroid hormones. Moreover, pathologic foals showed some hormonal and metabolic differences related to their health status. Above all changes of thyroid hormones levels, early in postnatal life, could be a cause, and not only a

  9. Influence of age on pulsatile luteinizing hormone release and responsiveness of the gonadotrophs to sex hormone feedback in men.

    PubMed

    Deslypere, J P; Kaufman, J M; Vermeulen, T; Vogelaers, D; Vandalem, J L; Vermeulen, A

    1987-01-01

    The influence of aging on serum LH and testosterone (T) pulse frequency and gonadotroph sensitivity to androgen and estrogen feedback was studied in young (less than 55 yr old) and elderly (greater than 65 yr) Trappist monks. LH pulse frequency (sampling interval, 20 min) was significantly lower [0.25 +/- 0.03 (+/- SEM) vs. 0.38 +/- 0.02 pulses/h; P less than 0.01] in elderly (n = 21) than in young monks (n = 27); the pulse amplitudes were similar. Similarly, T pulse frequency was lower in the elderly than in the young monks (0.13 +/- 0.04 vs. 0.23 +/- 0.02 pulses/h; P less than 0.01). In elderly men, the hypothalamo-pituitary complex was more sensitive to 5 alpha-androstan-17 beta-ol-3-one feedback, as determined by the decrease in serum LH and T levels. Moreover, during 5 alpha-androstan-17 beta-ol-3-one (125 mg/day, percutaneously, for 10 days) administration, the LH response to LHRH (100 micrograms, iv) was significantly higher in the elderly men compared to the pretreatment response. During estradiol (1.5 mg/day, percutaneously for 10 days) administration, the LH response to LHRH was decreased in the elderly men, but unchanged in the young men, suggesting greater responsiveness to estradiol in the elderly men. We conclude that in aged men, decreased testicular androgen secretion is not exclusively the consequence of a primary testicular alteration, but that important changes occur in hypothalamo-pituitary function, specifically decreased LH pulse frequency and increased LH responsiveness to sex hormone feedback.

  10. Influence of pH on the acute toxicity of ammonia to juvenile freshwater mussels (fatmucket, Lampsilis siliquoidea).

    PubMed

    Wang, Ning; Erickson, Russell J; Ingersoll, Christopher G; Ivey, Christopher D; Brunson, Eric L; Augspurger, Tom; Barnhart, M Christopher

    2008-05-01

    The objective of the present study was to evaluate the influence of pH on the toxicity of ammonia to juvenile freshwater mussels. Acute 96-h ammonia toxicity tests were conducted with 10-d-old juvenile mussels (fatmucket, Lampsilis siliquoidea) at five pH levels ranging from 6.5 to 9.0 in flow-through diluter systems at 20 degrees C. Acute 48-h tests with amphipods (Hyalella azteca) and 96-h tests with oligochaetes (Lumbriculus variegatus) were conducted concurrently under the same test conditions to determine the sensitivity of mussels relative to these two commonly tested benthic invertebrate species. During the exposure, pH levels were maintained within 0.1 of a pH unit and ammonia concentrations were relatively constant through time (coefficient of variation for ammonia concentrations ranged from 2 to 30% with a median value of 7.9%). The median effective concentrations (EC50s) of total ammonia nitrogen (N) for mussels were at least two to six times lower than the EC50s for amphipods and oligochaetes, and the EC50s for mussels decreased with increasing pH and ranged from 88 mg N/L at pH 6.6 to 0.96 mg N/L at pH 9.0. The EC50s for mussels were at or below the final acute values used to derive the U.S. Environmental Protection Agency's acute water quality criterion (WQC). However, the quantitative relationship between pH and ammonia toxicity to juvenile mussels was similar to the average relationship for other taxa reported in the WQC. These results indicate that including mussel toxicity data in a revision to the WQC would lower the acute criterion but not change the WQC mathematical representation of the relative effect of pH on ammonia toxicity.

  11. Determine the Influence of Time Held in “Knockdown” Anesthesia on Survival and Stress of Surgically Implanted Juvenile Salmonids

    SciTech Connect

    Woodley, Christa M.; Wagner, Katie A.; Knox, Kasey M.

    2012-01-31

    The Juvenile Salmon Acoustic Telemetry System (JSATS) was developed for the U.S. Army Corp of Engineers Portland District (USACE) to address questions related to survival and performance measures of juvenile salmonids as they pass through the Federal Columbia River Power System (FCRPS). Researchers using JSATS acoustic transmitters (ATs) were tasked with standardizing the surgical implantation procedure to ensure that the stressors of handling and surgery on salmonids were consistent and less likely to cause effects of tagging in survival studies. Researchers questioned whether the exposure time in 'knockdown' anesthesia (or induction) to prepare fish for surgery could influence the survival of study fish (CBSPSC 2011). Currently, fish are held in knockdown anesthesia after they reach Stage 4 anesthesia until the completion of the surgical implantation of a transmitter, varies from 5 to 15 minutes for studies conducted in the Columbia Basin. The Columbia Basin Surgical Protocol Steering Committee (CBSPSC ) expressed concern that its currently recommended 10-minute maximum time limit during which fish are held in anesthetic - tricaine methanesulfonate (MS-222, 80 mg L-1 water) - could increase behavioral and physiological costs, and/or decrease survival of outmigrating juvenile salmonids. In addition, the variability in the time fish are held at Stage 4 could affect the data intended for direct comparison of fish within or among survival studies. Under the current recommended protocol, if fish exceed the 10-minute time limit, they are to be released without surgical implantation, thereby increasing the number of fish handled and endangered species 'take' at the bypass systems for FCRPS survival studies.

  12. Influence of pH on the acute toxicity of ammonia to juvenile freshwater mussels (fatmucket, Lampsills siliquoidea)

    USGS Publications Warehouse

    Wang, N.; Erickson, R.J.; Ingersoll, C.G.; Ivey, C.D.; Brunson, E.L.; Augspurger, T.; Barnhart, M.C.

    2008-01-01

    The objective of the present study was to evaluate the influence of pH on the toxicity of ammonia to juvenile freshwater mussels. Acute 96-h ammonia toxicity tests were conducted with 10-d-old juvenile mussels (fatmucket, Lampsilis siliquoidea) at five pH levels ranging from 6.5 to 9.0 in flow-through diluter systems at 20??C. Acute 48-h tests with amphipods (Hyalella azteca) and 96-h tests with oligochaetes (Lumbriculus variegatus) were conducted concurrently under the same test conditions to determine the sensitivity of mussels relative to these two commonly tested benthic invertebrate species. During the exposure, pH levels were maintained within 0.1 of a pH unit and ammonia concentrations were relatively constant through time (coefficient of variation for ammonia concentrations ranged from 2 to 30% with a median value of 7.9%). The median effective concentrations (EC50s) of total ammonia nitrogen (N) for mussels were at least two to six times lower than the EC50s for amphipods and oligochaetes, and the EC50s for mussels decreased with increasing pH and ranged from 88 mg N/L at pH 6.6 to 0.96 mg N/L at pH 9.0. The EC50s for mussels were at or below the final acute values used to derive the U.S. Environmental Protection Agency's acute water quality criterion (WQC). However, the quantitative relationship between pH and ammonia toxicity to juvenile mussels was similar to the average relationship for other taxa reported in the WQC. These results indicate that including mussel toxicity data in a revision to the WQC would lower the acute criterion but not change the WQC mathematical representation of the relative effect of pH on ammonia toxicity. ?? 2008 SETAC.

  13. EFFECT OF ACUTE STRESS ON PLASMA CONCENTRATIONS OF SEX AND STRESS HORMONES IN JUVENILE ALLIGATORS LIVING IN CONTROL AND CONTAMINATED LAKES

    EPA Science Inventory

    Environmental contaminants can act as stressors, inducing elevated circulating concentrations of stress hormones such as corticosterone and cortisol. Development in contaminated eggs has been reported to modify circulating sex steroid hormone concentrations in alligators (Alligat...

  14. Novel NAD+-Farnesal Dehydrogenase from Polygonum minus Leaves. Purification and Characterization of Enzyme in Juvenile Hormone III Biosynthetic Pathway in Plant

    PubMed Central

    Mohamed-Hussein, Zeti-Azura; Ng, Chyan Leong

    2016-01-01

    Juvenile Hormone III is of great concern due to negative effects on major developmental and reproductive maturation in insect pests. Thus, the elucidation of enzymes involved JH III biosynthetic pathway has become increasing important in recent years. One of the enzymes in the JH III biosynthetic pathway that remains to be isolated and characterized is farnesal dehydrogenase, an enzyme responsible to catalyze the oxidation of farnesal into farnesoic acid. A novel NAD+-farnesal dehydrogenase of Polygonum minus was purified (315-fold) to apparent homogeneity in five chromatographic steps. The purification procedures included Gigacap S-Toyopearl 650M, Gigacap Q-Toyopearl 650M, and AF-Blue Toyopearl 650ML, followed by TSK Gel G3000SW chromatographies. The enzyme, with isoelectric point of 6.6 is a monomeric enzyme with a molecular mass of 70 kDa. The enzyme was relatively active at 40°C, but was rapidly inactivated above 45°C. The optimal temperature and pH of the enzyme were found to be 35°C and 9.5, respectively. The enzyme activity was inhibited by sulfhydryl agent, chelating agent, and metal ion. The enzyme was highly specific for farnesal and NAD+. Other terpene aldehydes such as trans- cinnamaldehyde, citral and α- methyl cinnamaldehyde were also oxidized but in lower activity. The Km values for farnesal, citral, trans- cinnamaldehyde, α- methyl cinnamaldehyde and NAD+ were 0.13, 0.69, 0.86, 1.28 and 0.31 mM, respectively. The putative P. minus farnesal dehydrogenase that’s highly specific towards farnesal but not to aliphatic aldehydes substrates suggested that the enzyme is significantly different from other aldehyde dehydrogenases that have been reported. The MALDI-TOF/TOF-MS/MS spectrometry further identified two peptides that share similarity to those of previously reported aldehyde dehydrogenases. In conclusion, the P. minus farnesal dehydrogenase may represent a novel plant farnesal dehydrogenase that exhibits distinctive substrate specificity

  15. In silico and bio assay of juvenile hormone analogs as an insect growth regulator against Galleria mellonella (wax moth) - Part I.

    PubMed

    Sharma, Priyanka; Thakur, Sunil; Awasthi, Pamita

    2016-05-01

    Juvenile hormone (JH) analogs are nowadays in use to control harmful pests. In order to develop new bioactive molecules as potential pesticides, we have incorporated different active structural features like sulfonamide, aromatic rings, amide group, and amino acid moiety to the base structure. We have screened a series of designed novel JH analogs against JH receptor protein (jhbpGm-2RCK) of Galleria mellonella in comparison to commercial insect growth regulators (IGRs) - Pyriproxyfen (T1) and Fenoxycarb (T2). All analogs exhibit the binding energy profile comparable to commercial IGRs. Based upon these results, a series of sulfonamide-based JHAs (T3-T8) as IGRs have been synthesized and characterized. Further, the efficacy of synthesized analogs (T3-T8) and commercial IGRs (Pyriproxyfen and Fenoxycarb) has been assessed against fourth instars larvae of G. mellonella under the laboratory conditions. LC50 values of all the analogs (T1-T8) against the fourth instars larvae were 9.99, 10.12, 24.76, 30.73, 38.45, 34.15, 34.14, 19.48 ppm and the LC90 153.27, 131.69, 112.15, 191.46, 427.02, 167.13, 217.10, 172.00 ppm, respectively. Among these analogs, N-(1-isopropyl-2-oxo-3-aza-3-N-ethyl-pentanyl)-p-toluene sulfonamide (T8) and N-(1-isopropyl-2-oxo-3-aza-3-N-ethyl-pentanyl) benzene sulfonamide (T7) exhibited the good pest larval mortality at different exposure periods (in hours) and different concentrations (in ppm) in comparison to in use IGRs- T1 and T2. Bio assay results are supported by docking at higher concentration. The present investigation clearly exhibits that analog T8 could serve as a potential IGR in comparison to in use IGRs (T1 and T2). The results are promising and provide new array of synthetic chemicals that may be utilized as IGRs.

  16. SEASONAL VARIATION IN PLASMA SEX STEROID CONCENTRATION IN JUVENILE ALLIGATORS

    EPA Science Inventory

    Seasonal variation in plasma sex steroid concentrations is common in mature vertebrates, and is occasionally seen in juvenile animals. In this study, we examine the seasonal pattern of sex hormone concentration in juvenile American alligators (Alligator mississippiensis) and make...

  17. [The influence of 24-epibrassidinole on the hormone status of wheat plants under sodium chloride].

    PubMed

    Aval'baev, A M; Iuldashev, R A; Fatkhutdinova, R A; Urusov, F A; Safutdinova, Iu V; Shakirova, F M

    2010-01-01

    We studied the influence of the preconditioning of wheat germ (Triticum aestivum L.) with 0.4 microM 24-epibrassidinole (EB) on the growth and hormone status of plants under the influence of 2% NaCl. The preconditioning with EB promoted the lowering of the extent of the damaging influence of pickling on the growth of germs. The important contribution to the realization of the protective action of EB in the preconditioning of plants is probably that of its ability to lower the level of stress-induced abscisic acid accumulation and the decrease in the content of indole-acetic acid. At the same time, the cytokinin concentration in plants preconditioned with EB under pickling was practically the same as in plants without stress. This fact combined with data about the ability of EB to induce the increase in cytokinin content in wheat, obtained before, allowed us to assume that the protective action of EB on plants is connected, first of all, with the prevention of the increase in level of hormones of cytokinin nature under pickling.

  18. Yolk hormones influence in ovo chemosensory learning, growth, and feeding behavior in domestic chicks.

    PubMed

    Bertin, Aline; Meurisse, Maryse; Arnould, Cécile; Leterrier, Christine; Constantin, Paul; Cornilleau, Fabien; Vaudin, Pascal; Burlot, Thierry; Delaveau, Joel; Rat, Christophe; Calandreau, Ludovic

    2016-03-01

    In this study, we assessed whether prenatal exposure to elevated yolk steroid hormones can influence in ovo chemosensory learning and the behavior of domestic chicks. We simulated a maternal environmental challenge by experimentally enhancing yolk progesterone, testosterone, and estradiol concentrations in hen eggs prior to incubation. The embryos from these hormones-treated eggs (HO) as well as sham embryos (O) that had received the vehicle-only were exposed to the odor of fish oil (menhaden) between embryonic Days 11 and 20. An additional group of control embryos (C) was not exposed to the odor. All chicks were tested following hatching for their feeding preferences between foods that were or were not odorized with the menhaden odor. In the 3-min choice tests, the behavior of O chicks differed significantly according to the type of food whereas C and HO chicks showed no preference between odorized and non-odorized food. Our result suggests weaker response in HO chicks. In addition, HO chicks showed impaired growth and reduced intake of an unfamiliar food on the 24-h time scale compared to controls. Our data suggest that embryonic exposure to increased yolk hormone levels can alter growth, chemosensory learning, and the development of feeding behaviors.

  19. Maternal and environmental influences on egg size and juvenile life-history traits in Pacific salmon

    PubMed Central

    Braun, Douglas C; Patterson, David A; Reynolds, John D

    2013-01-01

    Life-history traits such as fecundity and offspring size are shaped by investment trade-offs faced by mothers and mediated by environmental conditions. We use a 21-year time series for three populations of wild sockeye salmon (Oncorhynchus nerka) to test predictions for such trade-offs and responses to conditions faced by females during migration, and offspring during incubation. In years when their 1100 km upstream migration was challenged by high water discharges, females that reached spawning streams had invested less in gonads by producing smaller but not fewer eggs. These smaller eggs produced lighter juveniles, and this effect was further amplified in years when the incubation water was warm. This latter result suggests that there should be selection for larger eggs to compensate in populations that consistently experience warm incubation temperatures. A comparison among 16 populations, with matching migration and rearing environments but different incubation environments (i.e., separate spawning streams), confirmed this prediction; smaller females produced larger eggs for their size in warmer creeks. Taken together, these results reveal how maternal phenotype and environmental conditions can shape patterns of reproductive investment and consequently juvenile fitness-related traits within and among populations. PMID:23789081

  20. Hormonal effects on women's facial masculinity preferences: the influence of pregnancy, post-partum, and hormonal contraceptive use.

    PubMed

    Cobey, Kelly D; Little, Anthony C; Roberts, S Craig

    2015-01-01

    Here, we investigate changes in women's facial masculinity preferences across pregnancy and the post-partum period. The majority of previous research demonstrating changes in women's masculinity preferences has examined the impact of hormonal variation across the female menstrual cycle. Hormonal changes experienced during pregnancy and the post-partum period, critical periods in women's reproductive life histories, are considerably more extreme than the variation that occurs across the menstrual cycle, suggesting that differences in preferences may also be displayed during these times. We find that women's preference for masculinity in men's faces, but not women's faces, decreases in the post-partum period relative to pregnancy. Furthermore, when compared to a sample of nulliparous control participants, post-partum participants showed different masculinity preferences compared with women who were using hormonal contraception, with the direction of this difference dependent upon the sex of the face assessed.

  1. Influence of Acidification on the Partitioning of Steroid Hormones among Filtrate, Filter Media, and Retained Particulate Matter.

    PubMed

    Havens, Sonya M; Hedman, Curtis J; Hemming, Jocelyn D C; Mieritz, Mark G; Shafer, Martin M; Schauer, James J

    2016-09-01

    Hormone contamination of aquatic systems has been shown to have deleterious effects on aquatic biota. However, the assessment of hormone contamination of aquatic environments requires a quantitative evaluation of the potential effects of sample preservation on hormone concentrations. This study investigated the influence of acidification (pH 2) of surface water samples on the partitioning of hormones among filtrate, filter media, and filter-retained particulate matter. Hormones were spiked into unpreserved and sulfuric acid-preserved ultrapure water and surface water runoff samples. The samples were filtered, and hormones were extracted from the filter and filtrate and analyzed by high-performance liquid chromatography. Acidification did not influence the partitioning of hormones onto the filter media. For the majority of the hormones investigated in this study, the partitioning of hormones to the filter-retained particulate matter was not influenced by acidification. Acidification increased the partitioning of progesterone and melengestrol acetate onto the retained particulate matter (about 25% for both analytes). Incorporation of an isotopically labeled internal standard (ISTD) for progesterone accounted for the loss of progesterone to the filter-retained particulates and resulted in accurate concentrations of progesterone in the filtrate. The incorporation of an ISTD for melengestrol acetate, however, was unable to account for the loss of melengestrol acetate to the retained particulates and resulted in underestimations of melengestrol acetate in the filtrate. Our results indicate that the analysis of melengestrol acetate in acid preserved surface runoff samples should be conducted on the filter-retained particulates as well as the filtrate.

  2. Influence of methionine oxidation on the aggregation of recombinant human growth hormone.

    PubMed

    Mulinacci, Filippo; Poirier, Emilie; Capelle, Martinus A H; Gurny, Robert; Arvinte, Tudor

    2013-09-01

    Oxidation of methionine (Met) residues is one of the major chemical degradations of therapeutic proteins. This chemical degradation can occur at various stages during production and storage of a biotherapeutic drug. During the oxidation process, the side chain of methionine residue undergoes a chemical modification, with the thioether group substituted by a sulfoxide group. In previous papers, we showed that oxidation of the two most accessible methionine residues of recombinant human growth hormone (r-hGH), Met¹⁴ and Met¹²⁵, has no influence on the conformation of the protein [1]. However, the oxidized r-hGH is less thermally stable than the native protein [2]. In the current work, the consequences of the oxidation of these two methionine residues on the aggregation of r-hGH were investigated. The aggregation properties and kinetics of the native and oxidized r-hGH were measured in different buffers with both spectroscopic and chromatographic methods. Stabilities of oxidized and non-oxidized r-hGH were studied after storage at 37°C and freeze/thawing cycles. Methionine oxidation influenced the aggregation properties of r-hGH. In accelerated stability studies at 37°C, oxidized hormone aggregated more and faster than non-oxidized hormone. In freezing/thawing stability studies, it was found that oxidized r-hGH was less stable than its non-oxidized counterpart. In case of hGH, we have shown that chemical degradations such as oxidation can affect its physical stability and can induce aggregation.

  3. Habitat selection influences sex distribution, morphology, tissue biochemistry, and parasite load of juvenile coho salmon in the West Fork Smith River, Oregon

    EPA Science Inventory

    Given the strong influence of water temperature on salmonid physiology and behavior, in the summers of 2004 and 2005 we studied juvenile male and female coho salmon Oncorhynchus kisutch in two reaches of Oregon’s West Fork Smith River with different thermal profiles. Our goals we...

  4. Metabolism of testosterone by human granulosa cells in culture: influence of follicle-stimulating hormone and luteinizing hormone

    SciTech Connect

    Moon, Y.S.; Duleba, A.; Leung, P.C.; Gomel, V.

    1982-03-15

    Human granulosa cells were isolated from follicles (8 to 15 mm) and cultivated for 24 hours in the presence or absence of follicle-stimulating hormone (NIH-FSH-HS-1, 1 microgram/ml) and luteinizing hormone (NIAMDD-hLH-1, 1 microgram/ml). Testosterone -4-14C was added subsequently to all cultures for 4-, 6-, and 24-hour periods. Of the seven metabolites of testosterone studied, 17 beta-estradiol (E2) and estrone (E1) were the major products. In all patients, levels of E2 were three to ten times higher than those of E1. Production of E2, but not E1, was stimulated by either follicle-stimulating hormone (FSH) or luteinizing hormone (LH). The cells of the largest follicle (15 mm) showed greater response to LH than to FSH. Production of the other C19 and C18 metabolites was very low or negligible. These results further suggest that FSH regulates the aromatization of testosterone in human granulosa cells, and that LH may have the same effect on the matured follicle during the preovulatory period.

  5. Influence of Green Tides in Coastal Nursery Grounds on the Habitat Selection and Individual Performance of Juvenile Fish

    PubMed Central

    Murillo, Laurence; Randon, Marine; Lebot, Clément

    2017-01-01

    Coastal ecosystems, which provide numerous essential ecological functions for fish, are threatened by the proliferation of green macroalgae that significantly modify habitat conditions in intertidal areas. Understanding the influence of green tides on the nursery function of these ecosystems is essential to determine their potential effects on fish recruitment success. In this study, the influence of green tides on juvenile fish was examined in an intertidal sandy beach area, the Bay of Saint-Brieuc (Northwestern France), during two annual cycles of green tides with varying levels of intensity. The responses of three nursery-dependent fish species, the pelagic Sprattus sprattus (L.), the demersal Dicentrarchus labrax (L.) and the benthic Pleuronectes platessa L., were analysed to determine the effects of green tides according to species-specific habitat niche and behaviour. The responses to this perturbation were investigated based on habitat selection and a comparison of individual performance between a control and an impacted site. Several indices on different integrative scales were examined to evaluate these responses (antioxidant defence capacity, muscle total lipid, morphometric condition and growth). Based on these analyses, green tides affect juvenile fish differently according to macroalgal density and species-specific tolerance, which is linked to their capacity to move and to their distribution in the water column. A decreasing gradient of sensitivity was observed from benthic to demersal and pelagic fish species. At low densities of green macroalgae, the three species stayed at the impacted site and the growth of plaice was reduced. At medium macroalgal densities, plaice disappeared from the impacted site and the growth of sea bass and the muscle total lipid content of sprat were reduced. Finally, when high macroalgal densities were reached, none of the studied species were captured at the impacted site. Hence, sites affected by green tides are less

  6. The influence of ethanol and liver disease on sex hormones and hepatic oestrogen receptors in women.

    PubMed

    Becker, U

    1993-09-01

    In contrast to the numerous studies of men, very few studies have been concerned with sex hormone disturbances in women with chronic alcoholic and non-alcoholic liver diseases. The aim of the study was, to evaluate the effect of ethanol and liver dysfunction on menstrual cycle, serum sex hormone concentrations and hepatic oestrogen receptors in women. In premenopausal female alcoholics ethanol consumption increase the frequency of menstrual disturbances, abortions, and miscarriages, while infertility is not frequent. Acute ethanol intoxication has only minor effects on pituitary-gonadal hormones in premenopausal women, while chronic ethanol abuse lead to reduced concentrations of sulphated steroids, and these changes may be seen before severe liver dysfunction has appeared. In women liver dysfunction lead to earlier occurrence of menopause in comparison with normal controls, while information is insufficient or lacking regarding the influence upon fertility, pregnancy outcome and sexual behavior in women. In postmenopausal women with alcoholic and non-alcoholic liver disease, the main disturbances of sex hormone metabolism consist of elevated oestrone and sex hormone binding globulin (SHBG) concentrations, while serum concentrations of steroid sulphates and 5 alpha-dihydrotestosterone (DHT) are reduced, and the degree of liver dysfunction is a major determinant for the observed disturbances. The presence of high affinity, low capacity, specific oestrogen receptors (ER) in the liver is confirmed using a ligand binding assay (DCC), specificity analyses, and sucrose gradient centrifugation. Furthermore, the sensitivity of an enzyme immunoassay has been improved enabling the quantitative measurement of hepatic ER in 102 small liver biopsies from patients with alcoholic and non-alcoholic liver diseases. The method is suitable for quantitative assessment and ER in small tissue samples, and can be applied to other tissues than the liver. Patients with chronic liver

  7. Donor life stage influences juvenile American eel Anguilla rostrata attraction to conspecific chemical cues

    USGS Publications Warehouse

    Galbraith, Heather S.; Blakeslee, Carrie J.; Schmucker, Andrew K.; Johnson, Nicholas; Hansen, Michael J.; Li, Weiming

    2017-01-01

    The present study investigated the potential role of conspecific chemical cues in inland juvenile American eel Anguilla rostrata migrations by assessing glass eel and 1 year old elver affinities to elver washings, and elver affinity to adult yellow eel washings. In two-choice maze assays, glass eels were attracted to elver washings, but elvers were neither attracted to nor repulsed by multiple concentrations of elver washings or to yellow eel washings. These results suggest that A. rostrata responses to chemical cues may be life-stage dependent and that glass eels moving inland may use the odour of the previous year class as information to guide migration. The role of chemical cues and olfaction in eel migrations warrants further investigation as a potential restoration tool.

  8. Donor life stage influences juvenile American eel Anguilla rostrata attraction to conspecific chemical cues.

    PubMed

    Galbraith, H S; Blakeslee, C J; Schmucker, A K; Johnson, N S; Hansen, M J; Li, W

    2017-01-01

    The present study investigated the potential role of conspecific chemical cues in inland juvenile American eel Anguilla rostrata migrations by assessing glass eel and 1 year old elver affinities to elver washings, and elver affinity to adult yellow eel washings. In two-choice maze assays, glass eels were attracted to elver washings, but elvers were neither attracted to nor repulsed by multiple concentrations of elver washings or to yellow eel washings. These results suggest that A. rostrata responses to chemical cues may be life-stage dependent and that glass eels moving inland may use the odour of the previous year class as information to guide migration. The role of chemical cues and olfaction in eel migrations warrants further investigation as a potential restoration tool.

  9. Social influences on the acquisition of sex-typical foraging patterns by juveniles in a group of wild tufted capuchin monkeys (Cebus nigritus).

    PubMed

    Agostini, Ilaria; Visalberghi, Elisabetta

    2005-04-01

    Foraging traditions in primates are becoming the subject of increasing debate. Recent evidence for such a phenomenon was recently provided for wild Cebus capucinus [Fragaszy & Perry, 2003]. To better understand the bases of animal traditions, one should examine intrapopulation behavioral variability and the influence of social context on within-group transmission of specific foraging patterns. We studied the variability of foraging patterns across age and sex classes, and the proximity patterns of juveniles to adults of both sexes in a group of wild tufted capuchin monkeys (Cebus nigritus) living in the Iguazu National Park, Argentina. Foraging activity was examined for a period of 9 months in terms of proportions of focal samples devoted to foraging on certain food targets, microhabitats, and supports, and using specific foraging patterns. Proximity analyses were performed to reveal patterns of association between juveniles and adults. Sex differences in foraging behavior were present and overrode age differences. Overall, males ate more animal foods, foraged more for invertebrates on woody microhabitats (especially large branches), palms, and epiphytes, and used lower and larger supports than females. Females ate more fruits, foraged more on leaves and bamboo microhabitats, and used smaller supports than males. Juveniles were similar to adults of the same sex in terms of food targets, foraging substrates, and choice of supports, but were less efficient than adults. Proximity patterns indicated that juvenile males stayed in close spatial association with adult males and preferentially focused their "food interest" on them. This phenomenon was less evident in juvenile females. The degree to which juveniles, especially males, showed some of the sex-typical foraging patterns correlated positively with their proximity to adults of the same sex. These findings suggest that the acquisition of foraging behaviors by juvenile males is socially biased by their closeness to

  10. Understanding the influence of predation by introduced fishes on juvenile salmonids in the Columbia River Basin: Closing some knowledge gaps. Interim Report of Research 2010

    USGS Publications Warehouse

    Rose, Brien P.; Hansen, Gabriel S.; Mesa, Matthew G.

    2011-01-01

    In response to these recent concerns about the potential predatory impact of non-native piscivores on salmon survival, the Bonneville Power Administration (BPA) and the Columbia Basin Fish and Wildlife Authority (CBFWA) co-hosted a workshop to address predation on juvenile salmonids in the CRB by non-native fish (Halton 2008). The purpose of the workshop was to review, evaluate, and develop strategies to reduce predation by non-native fishes on juvenile salmonids. In the end, discussion at the workshop and at subsequent meetings considered two potential ideas to reduce predation by non-native fish on juvenile salmonids; (1) understanding the role of juvenile American shad Alosa sapidissima in the diet of non-native predators in the fall; and (2) the effects of localized, intense reductions of smallmouth bass in areas of particularly high salmonid predation. In this report, we describe initial efforts to understand the influence of juvenile American shad as a prey item for introduced predators in the middle Columbia River. Our first objective, addressed in Chapter 1, was to evaluate the efficacy of nonlethal methods to describe the physiological condition of smallmouth bass, walleye, and channel catfish from late summer through late fall. Such information will be used to understand the contribution of juvenile American shad to the energy reserves of predaceous fish prior to winter. In Chapter 2, we describe the results of some limited sampling to document the food habits of smallmouth bass, walleye, and channel catfish in three reservoirs of the middle Columbia River during late fall. Collectively, we hope to increase our understanding of the contribution of juvenile American shad to the diets of introduced predators and the contribution of this diet to their energy reserves, growth, and perhaps over-winter survival. Managers should be able to use this information for deciding whether to control the population of American shad in the CRB or for managing introduced

  11. Hormones and pheromones in regulation of insect behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Both pheromones and hormones are well recognized regulators of insect biology. However, the interactions between hormones and pheromones in coordinating insect biology are less well understood. We have studied the interactions between juvenile hormone, its precursor methyl farnesoate, and pheromon...

  12. In Vitro Growth and Steroidogenesis of Dog Follicles as Influenced by the Physical and Hormonal Microenvironment

    PubMed Central

    Songsasen, N; Woodruff, TK; Wildt, DE

    2011-01-01

    The present study examined the influences of physical and hormonal microenvironment on in vitro growth and steroidogenesis of dog follicles. Follicles were enzymatically-isolated and individually-encapsulated in 0.5% (w/v; n = 17) or 1.5% (n = 10) alginate and cultured with 0.5 IU/ml equine chorionic gonadotropin for 192 h. In a separate experiment, follicles were encapsulated in 0.5% alginate and cultured with 0 (n = 22), 1 (n= 23), 10 (n = 20) or 100 (n = 21) µg/ml FSH for 240 h. Follicle diameter and steroid production were assessed every 48 h in both studies. Follicles encapsulated in the 0.5% alginate grew faster (P < 0.05) than those cultured in the 1.5% concentration. Oestradiol (E2) and progesterone (P4) increased consistently (P < 0.05) over time, and follicles in the 1.5% alginate produced more (P < 0.05) P4 than those in the 0.5% solution. Follicles cultured in the highest FSH concentration (100 µg/ml) increased 100% in size after 240 h compared to 50 to 70% in lower dosages. E2 concentration remained unchanged over time (P > 0.05) across FSH dosages. However, P4 increased (P < 0.05) as culture progressed and with increasing FSH concentration. Results demonstrate that dog follicles cultured in alginate retain structural integrity, grow in size and are hormonally active. Lower alginate and increasing FSH concentrations promote in vitro follicle growth. However, the absence of an E2 rise in follicles cultured in FSH alone suggests the need for luteinizing hormone supplementation to support thecal cell differentiation and granulosa cell function. PMID:21502334

  13. Sex hormone influence on hepatitis in young male A/JCr mice infected with Helicobacter hepaticus.

    PubMed

    Theve, Elizabeth J; Feng, Yan; Taghizadeh, Koli; Cormier, Kathleen S; Bell, David R; Fox, James G; Rogers, Arlin B

    2008-09-01

    Hepatitis B virus (HBV), the leading cause of human hepatocellular carcinoma, is especially virulent in males infected at an early age. Likewise, the murine liver carcinogen Helicobacter hepaticus is most pathogenic in male mice infected before puberty. We used this model to investigate the influence of male sex hormone signaling on infectious hepatitis. Male A/JCr mice were infected with H. hepaticus or vehicle at 4 weeks and randomized into surgical and pharmacologic treatment groups. Interruption of androgen pathways was confirmed by hormone measurements, histopathology, and liver gene and Cyp4a protein expression. Castrated males and those receiving the competitive androgen receptor antagonist flutamide had significantly less severe hepatitis as determined by histologic activity index than intact controls at 4 months. Importantly, the powerful androgen receptor agonist dihydrotestosterone did not promote hepatitis. No effect on hepatitis was evident in males treated with the 5alpha-reductase inhibitor dutasteride, the peroxisome proliferator-activated receptor-alpha agonist bezafibrate, or the nonsteroidal anti-inflammatory drug flufenamic acid. Consistent with previous observations of hepatitis-associated liver-gender disruption, transcriptional alterations involved both feminine (cytochrome P450 4a14) and masculine (cytochrome P450 4a12 and trefoil factor 3) genes, as well gender-neutral (H19 fetal liver mRNA, lipocalin 2, and ubiquitin D) genes. Hepatitis was associated with increased unsaturated C(18) long-chain fatty acids (oleic acid and linoleic acid) relative to saturated stearic acid. Our results indicate that certain forms of androgen interruption can inhibit H. hepaticus-induced hepatitis in young male mice, whereas androgen receptor agonism does not worsen disease. This raises the possibility of targeted hormonal therapy in young male patients with childhood-acquired HBV.

  14. Influence of infection with Renibacterium salmoninarum on susceptibility of juvenile spring chinook salmon to gas bubble trauma

    USGS Publications Warehouse

    Weiland, L.K.; Mesa, M.G.; Maule, A.G.

    1999-01-01

    During experiments in our laboratory to assess the progression and severity of gas bubble trauma (GBT) in juvenile spring chinook salmon Oncorhynchus tshawytscha, we had the opportunity to assess the influence of Renibacterium salmoninarum (Rs), the causative agent of bacterial kidney disease, on the susceptibility of salmon to GBT. We exposed fish with an established infection of Rs to 120% total dissolved gas (TDG) for 96 h and monitored severity of GBT signs in the fins and gills, Rs infection level in kidneys by using an enzyme-linked immunosorbent assay (ELISA), and mortality. Mortality occurred rapidly after exposure to 120% TDG, with a LT20 (time necessary to kill 20% of the population) of about 37 h, which is at a minimum about 16% earlier than other bioassays we have conducted using fish that had no apparent signs of disease. Fish that died early (from 31 to 36 h and from 49 to 52 h) had significantly higher infection levels (mean ?? SE ELISA absorbance = 1.532 ?? 0.108) than fish that survived for 96h (mean ?? SE ELISA absorbance = 0.828 ?? 0.137). Fish that died early also had a significantly greater number of gill filaments occluded with bubbles than those that survived 96 h. Conversely, fish that survived for 96 h had a significantly higher median fin severity ranking than those that died early. Our results indicate that fish with moderate to high levels of Rs infection are more vulnerable to the effects of dissolved gas supersaturation (DGS) and die sooner than fish with lower levels of Rs infection. However, there is a substantial amount of individual variation in susceptibility to the apparent cumulative effects of DGS and Rs infection. Collectively, our findings have important implications to programs designed to monitor the prevalence and severity of GBT in juvenile salmonids in areas like the Columbia River basin and perhaps elsewhere.

  15. Influence of gender and sex hormones on nicotine acute pharmacological effects in mice.

    PubMed

    Damaj, M I

    2001-01-01

    The present study conducted a comprehensive examination of the putative sex differences in the potency of nicotine between male and female ICR mice using several pharmacological and behavioral tests. Among the responses to nicotine where significant sex differences were observed are the antinociceptive and the anxiolytic effects of nicotine. Female mice were found less sensitive to the acute effects of nicotine in these tests after s.c. administration. Similar gender differences were found after i.t. injection. Influence of gonadal hormones could underlie sex differences observed in our studies. Indeed, our data clearly indicate that sex hormones can modulate the effects of nicotine and nicotinic receptors in a differential manner. Progesterone and 17beta-estradiol were found to block nicotine's antinociception in mice. Testosterone failed to do so. In addition, progesterone and 17beta-estradiol blocked nicotine activation of alpha(4)beta(2) neuronal acetylcholine nicotinic receptors expressed in oocytes. Our findings contribute to our search for receptor mechanisms in drug dependence and in the discovery of better pharmacological agents for nicotine dependence.

  16. Do sex hormones influence emotional modulation of pain and nociception in healthy women?

    PubMed

    Rhudy, Jamie L; Bartley, Emily J; Palit, Shreela; Kerr, Kara L; Kuhn, Bethany L; Martin, Satin L; Delventura, Jennifer L; Terry, Ellen L

    2013-12-01

    Sex hormones may contribute to inter- and intra-individual differences in pain by influencing emotional modulation of pain and nociception. To study this, a well-validated picture-viewing paradigm was used to assess emotional modulation of pain and the nociceptive flexion reflex (NFR; physiologic measure of nociception) during mid-follicular, ovulatory, and late-luteal phases of the menstrual cycle in healthy normally cycling women (n=40). Salivary estradiol, progesterone, and testosterone were assessed at each testing session. Emotional modulation of pain/NFR did not differ across menstrual phases, but low estradiol was associated with weaker emotional modulation of NFR (during all phases) and emotional modulation of pain (ovulatory and late-luteal phases). Given evidence that a failure to emotionally modulate pain might be a risk factor for chronic pain, low estradiol may promote chronic pain via this mechanism. However, future research is needed to extend these findings to women with disturbances of pain, emotion, and/or sex hormones.

  17. Environmental Influences on the Spatial Ecology of Juvenile Smalltooth Sawfish (Pristis pectinata): Results from Acoustic Monitoring

    PubMed Central

    Simpfendorfer, Colin A.; Yeiser, Beau G.; Wiley, Tonya R.; Poulakis, Gregg R.; Stevens, Philip W.; Heupel, Michelle R.

    2011-01-01

    To aid recovery efforts of smalltooth sawfish (Pristis pectinata) populations in U.S. waters a research project was developed to assess how changes in environmental conditions within estuarine areas affected the presence, movements, and activity space of this endangered species. Forty juvenile P. pectinata were fitted with acoustic tags and monitored within the lower 27 km of the Caloosahatchee River estuary, Florida, between 2005 and 2007. Sawfish were monitored within the study site from 1 to 473 days, and the number of consecutive days present ranged from 1 to 125. Residency index values for individuals varied considerably, with annual means highest in 2005 (0.95) and lowest in 2007 (0.73) when several P. pectinata moved upriver beyond detection range during drier conditions. Mean daily activity space was 1.42 km of river distance. The distance between 30-minute centers of activity was typically <0.1 km, suggesting limited movement over short time scales. Salinity electivity analysis demonstrated an affinity for salinities between 18 and at least 24 psu, suggesting movements are likely made in part, to remain within this range. Thus, freshwater flow from Lake Okeechobee (and its effect on salinity) affects the location of individuals within the estuary, although it remains unclear whether or not these movements are threatening recovery. PMID:21347294

  18. Environmental influences on the spatial ecology of juvenile smalltooth sawfish (Pristis pectinata): results from acoustic monitoring.

    PubMed

    Simpfendorfer, Colin A; Yeiser, Beau G; Wiley, Tonya R; Poulakis, Gregg R; Stevens, Philip W; Heupel, Michelle R

    2011-02-11

    To aid recovery efforts of smalltooth sawfish (Pristis pectinata) populations in U.S. waters a research project was developed to assess how changes in environmental conditions within estuarine areas affected the presence, movements, and activity space of this endangered species. Forty juvenile P. pectinata were fitted with acoustic tags and monitored within the lower 27 km of the Caloosahatchee River estuary, Florida, between 2005 and 2007. Sawfish were monitored within the study site from 1 to 473 days, and the number of consecutive days present ranged from 1 to 125. Residency index values for individuals varied considerably, with annual means highest in 2005 (0.95) and lowest in 2007 (0.73) when several P. pectinata moved upriver beyond detection range during drier conditions. Mean daily activity space was 1.42 km of river distance. The distance between 30-minute centers of activity was typically <0.1 km, suggesting limited movement over short time scales. Salinity electivity analysis demonstrated an affinity for salinities between 18 and at least 24 psu, suggesting movements are likely made in part, to remain within this range. Thus, freshwater flow from Lake Okeechobee (and its effect on salinity) affects the location of individuals within the estuary, although it remains unclear whether or not these movements are threatening recovery.

  19. Influence of thermal challenge on conditioned feeding forays of juvenile rainbow trout

    SciTech Connect

    Munson, B.H.; McCormick, J.H.; Collins, H.L.

    1980-01-01

    Juvenile rainbow trout (Salmo gairdneri) conditioned to traverse a 2.4-m-long channel to receive a food reward were subjected to in-transit thermal challenges. Conditioning was to a criterion that required 80% of the fish to leave the home area and reach the reward area within 2 minutes of release. Challenges were at successive 3 C increments above acclimation or the previous challenge temperature. Fish were first observed to delay their entrance into the intervening heated water at challenge temperatures of 12 to 15 C above acclimation. At each increment above 12 to 15 C over acclimation temperature, delay in transit increased; however, complete group inhibition was never achieved. Above their critical thermal maximum (CTM) the reward was achieved even at the expense of deaths among the achievers. Responses were the same whether fish were challenged individually or as groups. Fish exposed to their CTM without prior challenges at less stressful temperatures responded similarly to those receiving progressively greater challenges.

  20. Influence of activating hormones on human platelet membrane Ca/sup 2 +/-ATPase activity

    SciTech Connect

    Resink, T.J.; Dimitrov, D.; Stucki, S.; Buehler, F.R.

    1986-07-16

    Intact platelets were pretreated with hormones and thereafter membranes were prepared and Ca/sup 2 +/-ATPase activity determined. Thrombin decreased the V/sub max/ of Ca/sup 2 +/-ATPase after pretreatment of intact platelets. Platelet activating factor, vasopressin and ADP also decreased Ca/sup 2 +/-ATPase activity. 12-O-tetradecanoylphorbol-13-acetate (TPA) or A23187 or ionomycin alone had no effect, while the simultaneous pretreatment with TPA and Ca/sup 2 +/-ionophore decreased Ca/sup 2 +/-ATPase activity. cAMP elevating agents prostaglandin E/sub 1/ (PGE/sub 1/) and forskolin had no influence per se on Ca/sup 2 +/-ATPase, but antagonized the inhibitory effect of thrombin. The data suggest a close connection between phosphoinositide metabolism and the Ca/sup 2 +/-ATPase system.

  1. CIRCULATING CONCENTRATIONS OF THYROID HORMONE IN BELUGA WHALES (DELPHINAPTERUS LEUCAS): INFLUENCE OF AGE, SEX, AND SEASON.

    PubMed

    Flower, Jennifer E; Allender, Matthew C; Giovanelli, Richard P; Summers, Sandra D; Spoon, Tracey R; St Leger, Judy A; Goertz, Caroline E C; Dunn, J Lawrence; Romano, Tracy A; Hobbs, Roderick C; Tuttle, Allison D

    2015-09-01

    Thyroid hormones play a critical physiologic role in regulating protein synthesis, growth, and metabolism. To date, because no published compilation of baseline values for thyroid hormones in beluga whales (Delphinapterus leucas) exists, assessment of thyroid hormone concentrations in this species has been underused in clinical settings. The purpose of this study was to document the concentrations of total thyroxine (tT4) and total triiodothyronine (tT3) in healthy aquarium-maintained and free-ranging beluga whales and to determine the influence of age, sex, and season on the thyroid hormone concentrations. Archived serum samples were collected from healthy aquarium-maintained (n=43) and free-ranging (n=39) belugas, and serum tT4 and tT3 were measured using chemiluminescence immunoassay. The mean tT4 concentration in aquarium-maintained belugas was 5.67±1.43 μg/dl and the mean tT3 concentration was 70.72±2.37 ng/dl. Sex comparisons showed that aquarium-maintained males had significantly greater tT4 and tT3 (9.70±4.48 μg/dl and 92.65±30.55 ng/dl, respectively) than females (7.18±2.82 μg/dl and 77.95±20.37 ng/dl) (P=0.004 and P=0.013). Age comparisons showed that aquarium-maintained whales aged 1-5 yr had the highest concentrations of tT4 and tT3 (8.17±0.17 μg/dl and 105.46±1.98 ng/dl, respectively) (P=0.002 and P<0.001). tT4 concentrations differed significantly between seasons, with concentrations in winter (4.59±1.09 μg/dl) being significantly decreased compared with spring (P=0.009), summer (P<0.0001), and fall (P<0.0001) concentrations. There was a significant difference in tT4 and tT3 concentrations between aquarium-maintained whales (5.67±1.43 μg/dl and 70.72±15.57 ng/dl, respectively) and free-ranging whales (11.71±3.36 μg/dl and 103.38±26.45 ng/dl) (P<0.0001 and P<0.001). Clinicians should consider biologic and environmental influences (age, sex, and season) for a more accurate interpretation of thyroid hormone concentrations in belugas

  2. Does resolution of flow field observation influence apparent habitat use and energy expenditure in juvenile coho salmon?

    USGS Publications Warehouse

    Tullos, Desiree D.; Walter, Cara; Dunham, Jason

    2016-01-01

    This study investigated how the resolution of observation influences interpretation of how fish, juvenile Coho Salmon (Oncorhynchus kisutch), exploit the hydraulic environment in streams. Our objectives were to evaluate how spatial resolution of the flow field observation influenced: (1) the velocities considered to be representative of habitat units; (2) patterns of use of the hydraulic environment by fish; and (3) estimates of energy expenditure. We addressed these objectives using observations within a 1:1 scale physical model of a full-channel log jam in an outdoor experimental stream. Velocities were measured with Acoustic Doppler Velocimetry at a 10 cm grid spacing, whereas fish locations and tailbeat frequencies were documented over time using underwater videogrammetry. Results highlighted that resolution of observation did impact perceived habitat use and energy expenditure, as did the location of measurement within habitat units and the use of averaging to summarize velocities within a habitat unit. In this experiment, the range of velocities and energy expenditure estimates increased with coarsening resolution (grid spacing from 10 to 100 cm), reducing the likelihood of measuring the velocities locally experienced by fish. In addition, the coarser resolutions contributed to fish appearing to select velocities that were higher than what was measured at finer resolutions. These findings indicate the need for careful attention to and communication of resolution of observation in investigating the hydraulic environment and in determining the habitat needs and bioenergetics of aquatic biota.

  3. How Doth the Little Crocodilian: Analyzing the Influence of Environmental Viscosity on Feeding Performance of Juvenile Alligator mississippiensis.

    PubMed

    Kerfoot, James R; Easter, Emily; Elsey, Ruth M

    2016-09-30

    Wetland habitats are used as nursery sites for hatchling and juvenile alligators (Alligator mississippiensis), where they utilize prey from aquatic and terrestrial settings. However, little is known about how viscosity of the medium influences feeding performance. We hypothesized that timing and linear excursion feeding kinematic variables would be different for individuals feeding on prey above the water compared with the same individuals feeding underwater. Individuals were fed immobile fish prey and feeding events were recorded using a high speed video camera. Feeding performance was summarized by analyzing three feeding kinematic variables (maximum gape, maximum gape velocity, duration of feeding bout) and success of strike. Results of a series of paired t-tests indicated no significant difference in kinematic variables between feeding events above water compared with underwater. Similarity in feeding performance could indicate that prey-capture is not altered by environmental viscosity or that feeding behavior can mitigate its influence. Behavioral differences were observed during feeding events with alligators approaching underwater prey having their mouths partially opened versus fully closed when feeding above water. This behavior could be an indication of a strategy used to overcome water viscosity.

  4. Short-term exposure to municipal wastewater influences energy, growth, and swimming performance in juvenile Empire Gudgeons (Hypseleotris compressa).

    PubMed

    Melvin, Steven D

    2016-01-01

    Effectively treating domestic wastewater is paramount for preserving the health of aquatic ecosystems. Various technologies exist for wastewater treatment, ranging from simple pond-based systems to advanced filtration, and it is important to evaluate the potential for these different options to produce water that is acceptable for discharge. Sub-lethal responses were therefore assessed in juvenile Empire Gudgeons (Hypseleotris compressa) exposed for a period of two weeks to control, 12.5, 25, 50, and 100% wastewater treated through a multi-stage constructed wetland (CW) treatment system. Effects on basic energy reserves (i.e., lipids and protein), growth and condition, and swimming performance were quantified following exposure. A significant increase in weight and condition was observed in fish exposed to 50 and 100% wastewater dilutions, whereas whole-body lipid content was significantly reduced in these treatments. Maximum swimming velocity increased in a dose-dependent manner amongst treatment groups (although not significantly), whereas angular velocity was significantly reduced in the 50 and 100% dilutions. Results demonstrate that treated domestic wastewater can influence the growth and swimming performance of fish, and that such effects may be related to alterations to primary energy stores. However, studies assessing complex wastewaters present difficulties when it comes to interpreting responses, as many possible factors can contribute towards the observed effects. Future research should address these uncertainties by exploring interaction between nutrients, basic water quality characteristics and relevant contaminant mixtures, for influencing the energetics, growth, and functional performance of aquatic animals.

  5. Sleep patterns in male juvenile monkeys are influenced by gestational iron deprivation and monoamine oxidase A genotype.

    PubMed

    Golub, Mari S; Hogrefe, Casey E

    2014-11-14

    Individual differences in sleep patterns of children may have developmental origins. In the present study, two factors known to influence behavioural development, monoamine oxidase A (MAOA) genotype and prenatal Fe-deficient (ID) diet, were examined for their influences on sleep patterns in juvenile rhesus monkeys. Sleep patterns were assessed based on a threshold for inactivity as recorded by activity monitors. Pregnant monkeys were fed diets containing either 100 parts per million (ppm) Fe (Fe sufficient, IS) or 10 ppm Fe (ID). At 3-4 months of age, male offspring were genotyped for polymorphisms of the MAOA gene that lead to high or low transcription. At 1 and 2 years of age, sleep patterns were assessed. Several parameters of sleep architecture changed with age. At 1 year of age, monkeys with the low-MAOA genotype demonstrated a trend towards more sleep episodes at night compared with those with the high-MAOA genotype. When monkeys reached 2 years of age, prenatal ID reversed this trend; ID in the low-MAOA group resulted in sleep fragmentation, more awakenings at night and more sleep episodes during the day when compared with prenatal IS in this genotype. The ability to consolidate sleep during the dark cycle was disrupted by prenatal ID, specifically in monkeys with the low-MAOA genotype.

  6. How Doth the Little Crocodilian: Analyzing the Influence of Environmental Viscosity on Feeding Performance of Juvenile Alligator mississippiensis

    PubMed Central

    Kerfoot, James R.; Easter, Emily; Elsey, Ruth M.

    2016-01-01

    Wetland habitats are used as nursery sites for hatchling and juvenile alligators (Alligator mississippiensis), where they utilize prey from aquatic and terrestrial settings. However, little is known about how viscosity of the medium influences feeding performance. We hypothesized that timing and linear excursion feeding kinematic variables would be different for individuals feeding on prey above the water compared with the same individuals feeding underwater. Individuals were fed immobile fish prey and feeding events were recorded using a high speed video camera. Feeding performance was summarized by analyzing three feeding kinematic variables (maximum gape, maximum gape velocity, duration of feeding bout) and success of strike. Results of a series of paired t-tests indicated no significant difference in kinematic variables between feeding events above water compared with underwater. Similarity in feeding performance could indicate that prey-capture is not altered by environmental viscosity or that feeding behavior can mitigate its influence. Behavioral differences were observed during feeding events with alligators approaching underwater prey having their mouths partially opened versus fully closed when feeding above water. This behavior could be an indication of a strategy used to overcome water viscosity. PMID:27706023

  7. Does resolution of flow field observation influence apparent habitat use and energy expenditure in juvenile coho salmon?

    NASA Astrophysics Data System (ADS)

    Tullos, Desirée.; Walter, Cara; Dunham, Jason

    2016-08-01

    This study investigated how the resolution of observation influences interpretation of how fish, juvenile Coho Salmon (Oncorhynchus kisutch), exploit the hydraulic environment in streams. Our objectives were to evaluate how spatial resolution of the flow field observation influenced: (1) the velocities considered to be representative of habitat units; (2) patterns of use of the hydraulic environment by fish; and (3) estimates of energy expenditure. We addressed these objectives using observations within a 1:1 scale physical model of a full-channel log jam in an outdoor experimental stream. Velocities were measured with Acoustic Doppler Velocimetry at a 10 cm grid spacing, whereas fish locations and tailbeat frequencies were documented over time using underwater videogrammetry. Results highlighted that resolution of observation did impact perceived habitat use and energy expenditure, as did the location of measurement within habitat units and the use of averaging to summarize velocities within a habitat unit. In this experiment, the range of velocities and energy expenditure estimates increased with coarsening resolution (grid spacing from 10 to 100 cm), reducing the likelihood of measuring the velocities locally experienced by fish. In addition, the coarser resolutions contributed to fish appearing to select velocities that were higher than what was measured at finer resolutions. These findings indicate the need for careful attention to and communication of resolution of observation in investigating the hydraulic environment and in determining the habitat needs and bioenergetics of aquatic biota.

  8. Influence of juvenile osteochondral conditions on racing performance in Thoroughbreds born in Normandy.

    PubMed

    Robert, Céline; Valette, Jean-Paul; Jacquet, Sandrine; Denoix, Jean-Marie

    2013-07-01

    The relationship between osteoarticular status and future athletic capacity is commonly accepted in equine practice, but there is little to support this belief in Thoroughbreds. The objective of this study was to assess the prevalence of juvenile osteochondral conditions (JOCC) in Thoroughbred yearlings and to investigate the significance of these with regard to subsequent racing performance. The radiographic files from 328 Thoroughbred yearlings born in Normandy were assessed in a consistent manner and entered into a database together with racing records. Logistic regression models were used to quantify the association between each radiographic parameter and racing performance (raced/not raced, placed/not placed, performer/not performer) at 2, 3, 4 and 5years of age. The front fetlock (30.2% of horses), the dorsal aspect of the hind fetlock (18%), the carpus (15.9%) and the distal part of the hock (15.5%) were the most commonly affected joints. Most horses (87.5%) raced either in turf flat races or in hurdle races. Starting a race at 2years old was more frequent for yearlings without radiographic findings (RF) on the carpus or with less than one RF of moderate severity. The proportions of horses placed at 3years old decreased with increasing number or severity of RF. In racing horses, there was no association between the presence of RF and earnings. The radiographic score, calculated as the sum of all the severity indices found on the radiographic file of the horse appeared well correlated with performance. Using this synthetic index might help veterinarians to evaluate radiographs of Thoroughbred yearlings for potential buyers.

  9. Urinary iodine and stable isotope analysis to examine habitat influences on thyroid hormones among coastal dwelling American alligators.

    PubMed

    Boggs, Ashley S P; Hamlin, Heather J; Nifong, James C; Kassim, Brittany L; Lowers, Russell H; Galligan, Thomas M; Long, Stephen E; Guillette, Louis J

    2016-01-15

    The American alligator, generally a freshwater species, is known to forage in marine environments despite the lack of a salt secreting gland found in other crocodylids. Estuarine and marine foraging could lead to increased dietary uptake of iodine, a nutrient necessary for the production of thyroid hormones. To explore the influence of dietary iodine on thyroid hormone health of coastal dwelling alligators, we described the seasonal plasma thyroxine and triiodothyronine concentrations measured by radioimmunoassay and urinary iodine (UI) concentrations measured by inductively coupled plasma mass spectrometry. We also analyzed long-term dietary patterns through stable isotope analysis of scute tissue. Snout-to-vent length (SVL) was a significant factor among UI and stable isotope analyses. Large adult males greater than 135cm SVL had the highest UI concentrations but did not display seasonality of thyroid hormones. Alligators under 135 SVL exhibited seasonality in thyroid hormones and a positive relationship between UI and triiodothyronine concentrations. Isotopic signatures provided supporting evidence that large males predominantly feed on marine/estuarine prey whereas females showed reliance on freshwater/terrestrial prey supplemented by marine/estuarine prey. UI measurement provided immediate information that correlated to thyroid hormone concentrations whereas stable isotope analysis described long-term dietary patterns. Both techniques demonstrate that adult alligators in coastal environments are utilizing estuarine/marine habitats, which could alter thyroid hormone physiology.

  10. Influence of species, size and relative abundance on the outcomes of competitive interactions between brook trout and juvenile coho salmon

    USGS Publications Warehouse

    Thornton, Emily J; Duda, Jeff; Quinn, Thomas P

    2016-01-01

    Resource competition between animals is influenced by a number of factors including the species, size and relative abundance of competing individuals. Stream-dwelling animals often experience variably available food resources, and some employ territorial behaviors to increase their access to food. We investigated the factors that affect dominance between resident, non-native brook trout and recolonizing juvenile coho salmon in the Elwha River, WA, USA, to see if brook trout are likely to disrupt coho salmon recolonization via interference competition. During dyadic laboratory feeding trials, we hypothesized that fish size, not species, would determine which individuals consumed the most food items, and that species would have no effect. We found that species, not size, played a significant role in dominance; coho salmon won 95% of trials, even when only 52% the length of their brook trout competitors. As the pairs of competing fish spent more time together during a trial sequence, coho salmon began to consume more food, and brook trout began to lose more, suggesting that the results of early trials influenced fish performance later. In group trials, we hypothesized that group composition and species would not influence fish foraging success. In single species groups, coho salmon consumed more than brook trout, but the ranges overlapped. Brook trout consumption remained constant through all treatments, but coho salmon consumed more food in treatments with fewer coho salmon, suggesting that coho salmon experienced more intra- than inter-specific competition and that brook trout do not pose a substantial challenge. Based on our results, we think it is unlikely that competition from brook trout will disrupt Elwha River recolonization by coho salmon.

  11. Influence of light and feeding conditions on swimming activity rhythms of larval and juvenile turbot. Scophthalmus maximus L.: An experimental study

    NASA Astrophysics Data System (ADS)

    Champalbert, Gisèle; Le Direach-Boursier, Laurence

    1998-12-01

    Turbot larvae are transported towards coastal nursery areas and live in very shallow waters. Food availability is assumed to be an important factor that retains them in such areas. To study the effects of a biotic factor (food) and an abiotic factor (light) that strongly influence behavioural mechanisms, experiments were carried out on laboratory-reared animals: larvae (1 cm), post-larvae (1.2 to 2.5 cm) and early juveniles (6 to 7 cm). Three kinds of apparatus and methods were used to record variations in swimming activity: (1) a phototaxis device to study orientation reactions in horizontal tanks; (2) actographs with infrared photoelectric barriers fitted around vertical cylindrical tanks; and (3) video cameras and cylindrical tanks. Observations were performed in total darkness and under dark-light regimes. Different types and quantities of food were provided to the fish. Larvae and juveniles of turbot exhibited a positive phototaxis from 1 to 1000 μW cm -2. At intensities lower than or equal to 0.1 μW cm -2, they did not exhibit clear reactions toward or away from the light. Turbot larvae and juveniles kept in total darkness did not show a clear rhythm of activity. Under natural illumination as well as in artificial LD conditions of similar periodicity, larvae swam by day and night. Live food ( Artemia nauplii or juvenile mysids) induced an immediate increase in activity or the maintenance of a high level of activity, which decreased over the following days. Recently metamorphosed turbot kept under LD conditions exhibited a clear rhythm with a nocturnal maximum. Food given at night did not induce swimming changes as long as food density remained low. At higher prey concentrations, increased activity during feeding was followed by reduced activity for more than 24 hours. A similar response pattern was noted when active food was given in large quantities during the day: juveniles displayed an immediate increase in activity, which subsequently decreased. Regular

  12. Effects of microplastics on juveniles of the common goby (Pomatoschistus microps): confusion with prey, reduction of the predatory performance and efficiency, and possible influence of developmental conditions.

    PubMed

    Carlos de Sá, Luís; Luís, Luís G; Guilhermino, Lúcia

    2015-01-01

    Microplastics (MP) are ubiquitous contaminants able to cause adverse effects on organisms. Three hypotheses were tested here: early Pomatoschistus microps juveniles can ingest MP; the presence of MP may reduce fish predatory performance and efficiency; developmental conditions may influence the preyselection capability of fish. Predatory bioassays were carried out with juveniles from two estuaries with differences in environmental conditions: Minho (M-est) and Lima (L-est) Rivers (NW Iberian coast). Polyethylene MP spheres (3 types) alone and in combination with Artemia nauplii were offered as prey.All the MP types were ingested, suggesting confusion with food. Under simultaneous exposure to MP and Artemia, L-est fish showed a significant reduction of the predatory performance (65%) and efficiency (upto 50%), while M-est fish did not, suggesting that developmental conditions may influence the preyselection capability of fish. The MP-induced reduction of food intake may decrease individual and population fitness.

  13. What is the influence of hormone therapy on homocysteine and crp levels in postmenopausal women?

    PubMed Central

    Lakryc, Eli Marcelo; Machado, Rogério Bonassi; Soares, José Maria; Fernandes, César Eduardo; Baracat, Edmund Chada

    2015-01-01

    OBJECTIVE: To evaluate the influence of estrogen therapy and estrogen-progestin therapy on homocysteine and C-reactive protein levels in postmenopausal women. METHODS: In total, 99 postmenopausal women were included in this double-blind, randomized clinical trial and divided into three groups: Group A used estrogen therapy alone (2.0 mg of 17β-estradiol), Group B received estrogen-progestin therapy (2.0 mg of 17 β-estradiol +1.0 mg of norethisterone acetate) and Group C received a placebo (control). The length of treatment was six months. Serum measurements of homocysteine and C-reactive protein were carried out prior to the onset of treatment and following six months of therapy. RESULTS: After six months of treatment, there was a 20.7% reduction in homocysteine levels and a 100.5% increase in C-reactive protein levels in the group of women who used estrogen therapy. With respect to the estrogen-progestin group, there was a 12.2% decrease in homocysteine levels and a 93.5% increase in C-reactive protein levels. CONCLUSION: Our data suggested that hormone therapy (unopposed estrogen or estrogen associated with progestin) may have a positive influence on decreasing cardiovascular risk due to a significant reduction in homocysteine levels. PMID:25789519

  14. Does the presence of microplastics influence the acute toxicity of chromium(VI) to early juveniles of the common goby (Pomatoschistus microps)? A study with juveniles from two wild estuarine populations.

    PubMed

    Luís, Luís G; Ferreira, Pedro; Fonte, Elsa; Oliveira, Miguel; Guilhermino, Lúcia

    2015-07-01

    Toxicological interactions between microplastics (MP) and other environmental contaminants are of grave concern. Here, the potential influence of MP in the short-term toxicity of chromium to early juveniles of Pomatoschistus microps was investigated. Three null hypotheses were tested: (1) exposure to Cr(VI) concentrations in the low ppm range does not induce toxic effects on juveniles; (2) the presence of microplastics in the water does not influence the acute toxicity of Cr(VI) to juveniles; (3) the environmental conditions of the natural habitat where fish developed do not influence their sensitivity to Cr(VI)-induced acute stress. Fish were collected in the estuaries of Minho (M-est) and Lima (L-est) Rivers (NW Iberian Peninsula) that have several abiotic differences, including in the water and sediment concentrations of various environmental contaminants. After acclimatization to laboratory conditions, two 96h acute bioassays were carried out with juveniles from both estuaries to: (i) investigate the effects of Cr(VI) alone; (ii) investigate the effects of Cr(VI) in the presence of MP (polyethylene spheres 1-5μm ∅). Cr(VI) alone induced mortality (96h-LC50s: 14.4-30.5mg/l) and significantly decreased fish predatory performance (≤74%). Thus, in the range of concentrations tested (5.6-28.4mg/l) Cr(VI) was found to be toxic to P. microps early juveniles, therefore, we rejected hypothesis 1. Under simultaneous exposure to Cr(VI) and MP, a significant decrease of the predatory performance (≤67%) and a significant inhibition of AChE activity (≤31%) were found. AChE inhibition was not observed in the test with Cr(VI) alone and MP alone caused an AChE inhibition ≤21%. Mixture treatments containing Cr(VI) concentration ≥3.9mg/l significantly increased LPO levels in L-est fish, an effect that was not observed under Cr(VI) or MP single exposures. Thus, toxicological interactions between Cr(VI) and MP occurred, therefore, we rejected hypothesis 2. In the

  15. INFLUENCE OF SUMMER TEMPERATURE SPATIAL VARIABILITY ON DISTRIBUTION AND CONDITION OF JUVENILE COHO SALMON

    EPA Science Inventory

    abstract

    Temperature during the summer months can influence the distribution, abundance and physiology of stream salmonids such as coho salmon (Oncorhynchus kisutch). Effects can be direct, via physiological responses, as well as indirect, via limited food resources, alter...

  16. Diagnostic Labeling in Juvenile Court: How Do Descriptions of Psychopathy and Conduct Disorder Influence Judges?

    ERIC Educational Resources Information Center

    Murrie, Daniel C.; Boccaccini, Marcus T.; McCoy, Wendy; Cornell, Dewey G.

    2007-01-01

    This study examined the influence of diagnostic criteria and diagnostic labels for psychopathy or conduct disorder on judicial decisions. A national sample of judges (N = 326) rendered hypothetical dispositions based on 1 of 12 mock psychological evaluations. The evaluations varied the presence of 2 sets of diagnostic criteria (antisocial…

  17. Sex and context: hormones and primate sexual motivation.

    PubMed

    Wallen, K

    2001-09-01

    Gonadal hormones regulate the ability to copulate in most mammalian species, but not in primates because copulatory ability has been emancipated from hormonal control. Instead, gonadal hormones primarily influence sexual motivation. This separation of mating ability from hormonally modulated mating interest allows social experience and context to powerfully influence the expression of sexual behavior in nonhuman primates, both developmentally and in adulthood. For example, male rhesus monkeys mount males and females equally as juveniles, but mount females almost exclusively as adults. Having ejaculated with a female better predicted this transition to female mounting partners than did increased pubertal testosterone (T). It is proposed that increased pubertal T stimulates male sexual motivation, increasing the male's probability of sexual experience with females, ultimately producing a sexual preference for females. Eliminating T in adulthood reduces male sexual motivation in both humans and rhesus monkeys, but does not eliminate the capacity to engage in sex. In male rhesus monkeys the effects of reduced androgens on sexual behavior vary with social status and sexual experience. Human sexual behavior also varies with hormonal state, social context, and cultural conventions. Ovarian hormones influence female sexual desire, but the specific sexual behaviors engaged in are affected by perceived pregnancy risk, suggesting that cognition plays an important role in human sexual behavior. How the physical capacity to mate became emancipated from hormonal regulation in primates is not understood. This emancipation, however, increases the importance of motivational systems and results in primate sexual behavior being strongly influenced by social context.

  18. Arg-Phe-amide-related peptides influence gonadotropin-releasing hormone neurons

    PubMed Central

    Kelestimur, Haluk; Kacar, Emine; Uzun, Aysegul; Ozcan, Mete; Kutlu, Selim

    2013-01-01

    The hypothalamic Arg-Phe-amide-related peptides, gonadotropin-inhibitory hormone and orthologous mammalian peptides of Arg-Phe-amide, may be important regulators of the hypothalamus-pituitary-gonadal reproductive axis. These peptides may modulate the effects of kisspeptins because they are presently recognized as the most potent activators of the hypothalamus-pituitary-gonadal axis. However, their effects on gonadotropin-releasing hormone neurons have not been investigated. In the current study, the GT1–7 cell line-expressing gonadotropin-releasing hormone was used as a model to explore the effects of Arg-Pheamide-related peptides on kisspeptin activation. Intracellular calcium concentration was quantified using the calcium-sensitive dye, fura-2 acetoxymethyl ester. Gonadotropin-releasing hormone released into the medium was detected via enzyme-linked immunosorbent assay. Results showed that 100 nmol/L kisspeptin-10 significantly increased gonadotropin-releasing hormone levels (at 120 minutes of exposure) and intracellular calcium concentrations. Co-treatment of kisspeptin with 1 μmol/L gonadotropin-inhibitory hormone or 1 μmol/L Arg-Phe-amide-related peptide-1 significantly attenuated levels of kisspeptin-induced gonadotropin-releasing hormone but did not affect kisspeptin-induced elevations of intracellular calcium concentration. Overall, the results suggest that gonadotropin-inhibitory hormone and Arg-Phe-amide-related peptide-1 may have inhibitory effects on kisspeptin-activated gonadotropin-releasing hormone neurons independent of the calcium signaling pathway. PMID:25206468

  19. Arg-Phe-amide-related peptides influence gonadotropin-releasing hormone neurons.

    PubMed

    Kelestimur, Haluk; Kacar, Emine; Uzun, Aysegul; Ozcan, Mete; Kutlu, Selim

    2013-06-25

    The hypothalamic Arg-Phe-amide-related peptides, gonadotropin-inhibitory hormone and orthologous mammalian peptides of Arg-Phe-amide, may be important regulators of the hypothalamus-pituitary-gonadal reproductive axis. These peptides may modulate the effects of kisspeptins because they are presently recognized as the most potent activators of the hypothalamus-pituitary-gonadal axis. However, their effects on gonadotropin-releasing hormone neurons have not been investigated. In the current study, the GT1-7 cell line-expressing gonadotropin-releasing hormone was used as a model to explore the effects of Arg-Pheamide-related peptides on kisspeptin activation. Intracellular calcium concentration was quantified using the calcium-sensitive dye, fura-2 acetoxymethyl ester. Gonadotropin-releasing hormone released into the medium was detected via enzyme-linked immunosorbent assay. Results showed that 100 nmol/L kisspeptin-10 significantly increased gonadotropin-releasing hormone levels (at 120 minutes of exposure) and intracellular calcium concentrations. Co-treatment of kisspeptin with 1 μmol/L gonadotropin-inhibitory hormone or 1 μmol/L Arg-Phe-amide-related peptide-1 significantly attenuated levels of kisspeptin-induced gonadotropin-releasing hormone but did not affect kisspeptin-induced elevations of intracellular calcium concentration. Overall, the results suggest that gonadotropin-inhibitory hormone and Arg-Phe-amide-related peptide-1 may have inhibitory effects on kisspeptin-activated gonadotropin-releasing hormone neurons independent of the calcium signaling pathway.

  20. Dual-axis hormonal covariation in adolescence and the moderating influence of prior trauma and aversive maternal parenting.

    PubMed

    Simmons, Julian G; Byrne, Michelle L; Schwartz, Orli S; Whittle, Sarah L; Sheeber, Lisa; Kaess, Michael; Youssef, George J; Allen, Nicholas B

    2015-09-01

    Adversity early in life can disrupt the functioning of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axes and increase risk for negative health outcomes. The interplay between these axes and the environment is complex, and understanding needs to be advanced by the investigation of the multiple hormonal relationships underlying these processes. The current study examined basal hormonal associations between morning levels of cortisol, testosterone, and dehydroepiandrosterone in a cohort of adolescents (mean age 15.56 years). The moderating influence of childhood adversity was also examined, as indexed by self-reported trauma (at mean age 14.91), and observed maternal aggressive parenting (at mean age 12.41). Between-person regressions revealed significant associations between hormones that were moderated by both measures of adversity. In females, all hormones positively covaried, but also interacted with adversity, such that positive covariation was typically only present when levels of trauma and/or aggressive parenting were low. In males, hormonal associations and interactions were less evident; however, interactions were detected for cortisol-testosterone - positively covarying at high levels of aggressive parenting but negatively covarying at low levels - and DHEA-cortisol - similarly positively covarying at high levels of parental aggression. These results demonstrate associations between adrenal and gonadal hormones and the moderating role of adversity, which is likely driven by feedback mechanisms, or cross-talk, between the axes. These findings suggest that hormonal changes may be the pathway through which early life adversity alters physiology and increases health risks, but does so differentially in the sexes; however further study is necessary to establish causation.

  1. Constitutional Delay Influences the Auxological Response to Growth Hormone Treatment in Children with Short Stature and Growth Hormone Sufficiency

    PubMed Central

    Gunn, Katherine C.; Cutfield, Wayne S.; Hofman, Paul L.; Jefferies, Craig A.; Albert, Benjamin B.; Gunn, Alistair J.

    2014-01-01

    In a retrospective, population based cohort study, we examined whether constitutional delay was associated with the growth response to growth hormone (GH) in children with short stature and normal GH responses. 70 patients were treated with 21 GH iu/m2/week from 1975 to 2013 throughout New Zealand. Demographic and auxological data were prospectively collected and standard deviation scores (SDS) were calculated for height (HtSDS), yearly growth velocity (GV-SDS), body mass index (BMI-SDS) and predicted adult height (PAH-SDS) at time of the last available bone age. In the first year, GH was associated with marked increase in HtSDS (+0.46 (0.19, 0.76), p < 0.001) and GV-SDS (from −1.9 (−3.6, −0.7) to +2.7 (0.45, 4.2), p < 0.001). The increase in HtSDS but not in GV-SDS was greatest with younger patients and greater bone age delay, with no effect of sex, BMI-SDS or baseline HtSDS. PAH-SDS increased with treatment (+0.94 (0.18, 1.5)); increased PAH-SDS was associated with less bone age delay and greater initial increase in HtSDS. This study shows that greater bone age delay was associated with greater initial improvement in height but less improvement in predicted adult heights, suggesting that children with very delayed bone ages may show accelerated maturation during GH treatment. PMID:25317732

  2. Influence of gonadal hormones on the behavioral effects of intermittent hypoxia in mice

    PubMed Central

    Jenkins, Richelle; Magalang, Ulysses J.; Nelson, Randy J.

    2014-01-01

    Obstructive sleep apnea (OSA) is characterized by repetitive upper airway obstruction resulting in cyclic intermittent hypoxia (IH) during sleep in affected individuals. OSA occurs more frequently in postmenopausal than premenopausal women and the severity of OSA increases after menopause. Gonadal hormones can influence brain and behavior; testosterone and estrogens in particular can enhance spatial learning and memory. We hypothesized that estrogens may protect mice from IH-induced hippocampal morphological and behavioral changes. To test this hypothesis we exposed intact or gonadectomized male and female mice to room air or IH [15 cycles/h, 8 h/day, fraction of inspired oxygen (FiO2) nadir of 5%] for a total of 30 days. During the final 4 days of IH, mice were tested for anxiety- and depressive-like behaviors. After cessation of IH exposure mice were tested on the Barnes maze and passive avoidance tests to assess learning and memory. Ovariectomy paired with IH treatment, impaired spatial learning and memory compared to all other female groups. Intact male mice receiving IH treatment also had impaired learning and memory compared with intact or castrated male mice exposed to room air. Learning and memory changes were mirrored by changes in basilar dendritic length of the CA1 region of the hippocampus. These data suggest that estrogens provide protection against IH-induced deficits, whereas androgens partially exacerbate IH-induced deficits on learning and memory. PMID:25552660

  3. Growth Hormone Influence on the Morphology and Size of the Mouse Meibomian Gland

    PubMed Central

    Liu, Yang; Knop, Erich; Knop, Nadja; Sullivan, David A.; List, Edward O.; Kopchick, John J.; Kam, Wendy R.; Ding, Juan

    2016-01-01

    Purpose. We hypothesize that growth hormone (GH) plays a significant role in the regulation of the meibomian gland. To test our hypothesis, we examined the influence of GH on mouse meibomian gland structure. Methods. We studied four groups of mice, including (1) bovine (b) GH transgenic mice with excess GH; (2) GH receptor (R) antagonist (A) transgenic mice with decreased GH; (3) GHR knockout (−/−) mice with no GH activity; and (4) wild type (WT) control mice. After mouse sacrifice, eyelids were processed for morphological and image analyses. Results. Our results show striking structural changes in the GH-deficient animals. Many of the GHR−/− and GHA meibomian glands featured hyperkeratinized and thickened ducts, acini inserting into duct walls, and poorly differentiated acini. In contrast, the morphology of WT and bGH meibomian glands appeared similar. The sizes of meibomian glands of bGH mice were significantly larger and those of GHA and GHR−/− mice were significantly smaller than glands of WT mice. Conclusions. Our findings support our hypothesis that the GH/IGF-1 axis plays a significant role in the control of the meibomian gland. In addition, our data show that GH modulates the morphology and size of this tissue. PMID:26981277

  4. Climate influence on juvenile European sea bass (Dicentrarchus labrax, L.) populations in an estuarine nursery: A decadal overview.

    PubMed

    Bento, Eduardo G; Grilo, Tiago F; Nyitrai, Dániel; Dolbeth, Marina; Pardal, Miguel Ângelo; Martinho, Filipe

    2016-12-01

    Estuarine systems support the life cycle stages of commercially important marine fish and are influenced by large and local-scale climatic patterns. In this study, performed in the Mondego estuary, Portugal, we used an 11-year database (2003-2013) for analyzing the variability in the population of a marine juvenile migrant fish, the European sea bass Dicentrarchus labrax, regarding changes in abundance, population structure, growth rates, secondary production and annual day of peak abundance. Higher densities and production occurred in 2003, but no differences in 0-group growth could be observed. In order to detect change points in both biological and climatic data, the cumulative sum (CUSUM) of the deviations from the mean for the 2003-2013 period were determined for each parameter. The relationship between large and local-scale drivers and 0-group biological attributes were evaluated using a Spearman rank correlation analysis of CUSUM of biological and environmental data, considering the correspondent yearly values and with a time-lag of 1 year. The North Atlantic Oscillation (NAO) index, sea surface temperature (SST) and their respective winter values were tested as large-scale factors, while river runoff, salinity and estuarine water temperature were considered as local climate patterns. The significant factors explaining D. labrax 0-group abundance and production were salinity and the NAO, the latter being also a significant predictor considering the 1-year lag. The NAO with 1-year lag was also positively correlated with the day of peak abundance. The early stages of European sea bass were demonstrated to have a climate-dependent life cycle, controlled by variations in both large-scale climatic patterns and local features. In southern European marine populations, the effects of the NAO seem less direct, and dependent on the magnitude of its expressions and on the time scale considered.

  5. The Influence of Menopausal Status and Postmenopausal Use of Hormone Therapy on Presentation of Major Depression in Women

    PubMed Central

    Kornstein, Susan G.; Young, Elizabeth A.; Harvey, Annie T.; Wisniewski, Stephen R.; Barkin, Jennifer L.; Thase, Michael E.; Trivedi, Madhukar H.; Nierenberg, Andrew A.; Rush, A. John

    2010-01-01

    Objective: The purpose of this study was to determine whether there are differences in depression characteristics among premenopausal, perimenopausal, and postmenopausal women with major depressive disorder. This study also evaluated these differences between postmenopausal women with major depressive disorder who are taking and not taking hormone therapy. Methods: Analyses conducted with data from the Sequenced Treatment Alternatives to Relieve Depression study focused on female outpatients with non-psychotic major depressive disorder seeking treatment in 41 primary or psychiatric care settings across the United States. Baseline demographic and clinical characteristics were compared among women not taking hormone therapy who were premenopausal (N=950), perimenopausal (N=380), or postmenopausal (N=562). These comparisons were also made between postmenopausal women (n=768) taking (N=171) or not taking (N=562) hormone therapy. Results: After adjusting for sociodemographic and clinical baseline differences, premenopausal women were more likely to present with irritability than either peri- or postmenopausal women, and were more likely to have decreased appetite and less likely to have early morning insomnia than perimenopausal women. Postmenopausal women were more likely to have suicidal ideation and poorer physical functioning than either of the other groups, and were more likely to have sympathetic arousal and gastrointestinal symptoms than premenopausal women. After adjusting for baseline differences, postmenopausal women taking hormone therapy had better physical functioning, fewer melancholic features, less sympathetic arousal, and more lack of involvement in activities than women not taking hormone therapy. Conclusions: Menopausal status and postmenopausal use of hormone therapy may influence the clinical presentation of major depressive episodes in women. PMID:20616669

  6. Mutual influences between partners' hormones shape conflict dialog and relationship duration at the initiation of romantic love.

    PubMed

    Schneiderman, Inna; Kanat-Maymon, Yaniv; Zagoory-Sharon, Orna; Feldman, Ruth

    2014-01-01

    Early-stage romantic love involves reorganization of neurohormonal systems and behavioral patterns marked by mutual influences between the partners' physiology and behavior. Guided by the biobehavioral synchrony conceptual frame, we tested bidirectional influences between the partners' hormones and conflict behavior at the initiation of romantic love. Participants included 120 new lovers (60 couples) and 40 singles. Plasma levels of five affiliation and stress-related hormones were assessed: oxytocin (OT), prolactin (PRL), testosterone (T), cortisol (CT), and dehydroepiandrosterone sulfate (DHEAS). Couples were observed in conflict interaction coded for empathy and hostility. CT and DHEAS showed direct actor effects: higher CT and DHEAS predicted greater hostility. OT showed direct partner effects: individuals whose partners had higher OT showed greater empathy. T and CT showed combined actor-partner effects. High T predicted greater hostility only when partner also had high T, but lower hostility when partner had low T. Similarly, CT predicted low empathy only in the context of high partner's CT. Mediational analysis indicated that combined high CT in both partners was associated with relationship breakup as mediated by decrease in empathy. Findings demonstrate the mutual influences between hormones and behavior within an attachment bond and underscore the dynamic, co-regulated, and systemic nature of pair-bond formation in humans.

  7. Growth Hormone Action Influences Adipogenesis of Mouse Adipose Tissue-Derived Mesenchymal Stem Cells

    PubMed Central

    Olarescu, Nicoleta C; Berryman, Darlene E; Householder, Lara A; Lubbers, Ellen R; List, Edward O; Benencia, Fabian; Kopchick, John J; Bollerslev, Jens

    2015-01-01

    Growth hormone (GH) influences adipocyte differentiation, but both stimulatory and inhibitory effects have been described. Adipose tissue-derived mesenchymal stem cells (AT-MSC) are multipotent, able to differentiate into adipocytes, among other cells. Canonical Wnt/β-catenin signaling activation impairs adipogenesis. The aim of this study was to elucidate the role of GH on AT-MSC adipogenesis using cells isolated from male GH receptor gene knockout (GHRKO), bovine GH transgenic (bGH) and wild-type littermate control (WT) mice. AT-MSC from subcutaneous (sc), epididiymal (epi), and mesenteric (mes) AT depots were identified and isolated by flow cytometry (PDGFRα+Sca-1+CD45−Ter119− cells). Their in vitro adipogenic differentiation capacity was determined by cell morphology and real-time RT-PCR. Using identical in vitro conditions, adipogenic differentiation of AT-MSC was only achieved in the sc depot, but not in epi and mes depots. Notably, we observed an increased differentiation in cells isolated from sc-GHRKO and an impaired differentiation of sc-bGH cells compared with sc-WT cells. Axin-2, a marker of Wnt/β-catenin activation, was increased in mature sc-bGH adipocytes suggesting that activation of this pathway may be responsible for the decreased adipogenesis. Thus, we demonstrate that 1) adipose tissue in mice has a well-defined population of Sca-1+PDGFRα+ MSC cells; 2) the differentiation capacity of AT-MSC varies from depot to depot regardless of GH genotype; 3) the lack of GH action increases adipogenesis in sc depot; and 4) activation of Wnt/β-catenin pathway might mediate the GH effect on AT-MSC. Taken together, our results suggest that GH diminishes fat mass, in part, by altering adipogenesis of MSC. PMID:25943560

  8. Juvenile Firesetting.

    PubMed

    Peters, Brittany; Freeman, Bradley

    2016-01-01

    Juvenile firesetting is a significant cause of morbidity and mortality in the United States. Male gender, substance use, history of maltreatment, interest in fire, and psychiatric illness are commonly reported risk factors. Interventions that have been shown to be effective in juveniles who set fires include cognitive behavior therapy and educational interventions, whereas satiation has not been shown to be an effective intervention. Forensic assessments can assist the legal community in adjudicating youth with effective interventions. Future studies should focus on consistent assessment and outcome measures to create more evidence for directing evaluation and treatment of juvenile firesetters.

  9. Influence of enteral glutamine on inflammatory and hormonal response in patients with rectal cancer during preoperative radiochemotherapy.

    PubMed

    Rotovnik Kozjek, N; Kompan, L; Žagar, T; Mrevlje, Ž

    2017-03-08

    We conducted a randomized double-blind placebo-controlled study evaluating the influence of 5 weeks' duration of 30 g enteral glutamine supplementation on inflammatory and hormonal responses in 73 patients with rectal cancer undergoing preoperative radiochemotherapy. Plasma levels of inflammatory and hormonal parameters were controlled at the beginning and at the end of supplementation. Enteral glutamine resulted in modulation of inflammatory and hormonal responses as shown by a decreased plasma interleukin 6 and cortisol levels in glutamine compared with placebo group: 5.5±3.8 versus 11.1±19.9 ng/l (P=0.02) for IL-6 and 386±168.4 to 312.7±111.7 nmol/l (P=0.03) for cortisol. We conclude that enteral glutamine exhibits some anti-inflammatory activity and, consequently, leads to a lower hormonal stress response during radiochemotherapy in patients with rectal cancer.European Journal of Clinical Nutrition advance online publication, 8 March 2017; doi:10.1038/ejcn.2017.11.

  10. Understanding Risky Behavior: The Influence of Cognitive, Emotional and Hormonal Factors on Decision-Making under Risk

    PubMed Central

    Kusev, Petko; Purser, Harry; Heilman, Renata; Cooke, Alex J.; Van Schaik, Paul; Baranova, Victoria; Martin, Rose; Ayton, Peter

    2017-01-01

    Financial risky decisions and evaluations pervade many human everyday activities. Scientific research in such decision-making typically explores the influence of socio-economic and cognitive factors on financial behavior. However, very little research has explored the holistic influence of contextual, emotional, and hormonal factors on preferences for risk in insurance and investment behaviors. Accordingly, the goal of this review article is to address the complexity of individual risky behavior and its underlying psychological factors, as well as to critically examine current regulations on financial behavior. PMID:28203215

  11. The Influence of Tag Presence on the Mortality of Juvenile Chinook Salmon Exposed to Simulated Hydroturbine Passage: Implications for Survival Estimates and Management of Hydroelectric Facilities

    SciTech Connect

    Carlson, Thomas J.; Brown, Richard S.; Stephenson, John R.; Pflugrath, Brett D.; Colotelo, Alison HA; Gingerich, Andrew J.; Benjamin, Piper L.; Langeslay, Mike; Ahmann, Martin L.; Johnson, Robert L.; Skalski, John R.; Seaburg, Adam; Townsend, Richard L.

    2012-05-01

    Each year, millions of fish have telemetry tags (acoustic, radio, inductive) surgically implanted to assess their passage and survival through hydropower facilities. One route of passage of particular concern is through hydro turbines, in which fish may be exposed to a range of potential injuries, including barotraumas from rapid decompression. The change in pressure from acclimation to exposure (nadir) has been found to be an important factor in predicting the likelihood of mortality and injury for juvenile Chinook salmon undergoing rapid decompression associated with simulated turbine passage. The presence of telemetry tags has also been shown to influence the likelihood of injury and mortality for juvenile Chinook salmon. This research investigated the likelihood of mortality and injury for juvenile Chinook salmon carrying telemetry tags and exposed to a range of simulated turbine passage. Several factors were examined as predictors of mortal injury for fish undergoing rapid decompression, and the ratio of pressure change and tag burden were determined to be the most predictive factors. As the ratio of pressure change and tag burden increase, the likelihood of mortal injury also increases. The results of this study suggest that previous survival estimates of juvenile Chinook salmon passing through hydro turbines may have been biased due to the presence of telemetry tags, and this has direct implications to the management of hydroelectric facilities. Realistic examples indicate how the bias in turbine passage survival estimates could be 20% or higher, depending on the mass of the implanted tags and the ratio of acclimation to exposure pressures. Bias would increase as the tag burden and pressure ratio increase, and have direct implications on survival estimates. It is recommended that future survival studies use the smallest telemetry tags possible to minimize the potential bias that may be associated with carrying the tag.

  12. Juvenile Prostitution.

    ERIC Educational Resources Information Center

    Csapo, Marg

    1986-01-01

    Recent research and Canadian government committee reports concerning juvenile prostitution are reviewed. Proposals are made in the realms of law and social policy; and existing programs are described. (DB)

  13. Cold tolerance in juvenile sorghum is associated with root traits and is influenced by accumulation of soluble sugars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold tolerance at seedling/juvenile stage is an important and desirable trait in sorghum cultivars grown in northern latitudes. To address the need for this favorable trait, analysis of the important metabolites during cold stress treatment using a sorghum diversity panel was conducted and results ...

  14. Influence of Parent-Child Relationships on the Global Self-Worth and Morality of Juvenile Delinquents

    ERIC Educational Resources Information Center

    Forney, William Scott; Crutsinger, Christy; Forney, Judith Cardona

    2006-01-01

    This study explored the effects of parent-child relationships on the global self-worth and morality of juvenile delinquents. Participants were adjudicated as first-time shoplifting/theft offenders. Factor analyses of three self-esteem scales revealed two reliable parent-child relationship (conduct around parents and interactions with parents) and…

  15. The influence of trilostane on steroid hormone metabolism in canine adrenal glands and corpora lutea-an in vitro study.

    PubMed

    Ouschan, C; Lepschy, M; Zeugswetter, F; Möstl, E

    2012-03-01

    Trilostane is widely used to treat hyperadrenocorticism in dogs. Trilostane competitively inhibits the enzyme 3-beta hydroxysteroid dehydrogenase (3β-HSD), which converts pregnenolone (P5) to progesterone (P4) and dehydroepiandrosterone (DHEA) to androstendione (A4). Although trilostane is frequently used in dogs, the molecular mechanism underlying its effect on canine steroid hormone biosynthesis is still an enigma. Multiple enzymes of 3β-HSD have been found in humans, rats and mice and their presence might explain the contradictory results of studies on the effectiveness of trilostane. We therefore investigated the influence of trilostane on steroid hormone metabolism in dogs by means of an in vitro model. Canine adrenal glands from freshly euthanized dogs and corpora lutea (CL) were incubated with increasing doses of trilostane. Tritiated P5 or DHEA were used as substrates. The resulting radioactive metabolites were extracted, separated by thin layer chromatography and visualized by autoradiography. A wide variety of radioactive metabolites were formed in the adrenal glands and in the CL, indicating high metabolic activity in both tissues. In the adrenal cortex, trilostane influences the P5 metabolism in a dose- and time-dependent manner, while DHEA metabolism and metabolism of both hormones in the CL were unaffected. The results indicate for the first time that there might be more than one enzyme of 3β-HSD present in dogs and that trilostane selectively inhibits P5 conversion to P4 only in the adrenal gland.

  16. The Drosophila Juvenile Hormone Receptor Candidates Methoprene-tolerant (MET) and Germ Cell-expressed (GCE) Utilize a Conserved LIXXL Motif to Bind the FTZ-F1 Nuclear Receptor*

    PubMed Central

    Bernardo, Travis J.; Dubrovsky, Edward B.

    2012-01-01

    Juvenile hormone (JH) has been implicated in many developmental processes in holometabolous insects, but its mechanism of signaling remains controversial. We previously found that in Drosophila Schneider 2 cells, the nuclear receptor FTZ-F1 is required for activation of the E75A gene by JH. Here, we utilized insect two-hybrid assays to show that FTZ-F1 interacts with two JH receptor candidates, the bHLH-PAS paralogs MET and GCE, in a JH-dependent manner. These interactions are severely reduced when helix 12 of the FTZ-F1 activation function 2 (AF2) is removed, implicating AF2 as an interacting site. Through homology modeling, we found that MET and GCE possess a C-terminal α-helix featuring a conserved motif LIXXL that represents a novel nuclear receptor (NR) box. Docking simulations supported by two-hybrid experiments revealed that FTZ-F1·MET and FTZ-F1·GCE heterodimer formation involves a typical NR box-AF2 interaction but does not require the canonical charge clamp residues of FTZ-F1 and relies primarily on hydrophobic contacts, including a unique interaction with helix 4. Moreover, we identified paralog-specific features, including a secondary interaction site found only in MET. Our findings suggest that a novel NR box enables MET and GCE to interact JH-dependently with the AF2 of FTZ-F1. PMID:22249180

  17. Quantitative determination of juvenile hormone III and 20-hydroxyecdysone in queen larvae and drone pupae of Apis mellifera by ultrasonic-assisted extraction and liquid chromatography with electrospray ionization tandem mass spectrometry.

    PubMed

    Zhou, Jinhui; Qi, Yitao; Hou, Yali; Zhao, Jing; Li, Yi; Xue, Xiaofeng; Wu, Liming; Zhang, Jinzhen; Chen, Fang

    2011-09-01

    In this paper, a method for the rapid and sensitive analysis of juvenile hormone III (JH III) and 20-hydroxyecdysone (20E) in queen larvae and drone pupae samples was presented. Ultrasound-assisted extraction provided a significant shortening of the leaching time for the extraction of JH III and 20E and satisfactory sensitivity as compared to the conventional shake extraction procedure. After extraction, determination was carried out by liquid chromatography-tandem mass spectrometry (LC-MS/MS) operating in electrospray ionization positive ion mode via multiple reaction monitoring (MRM) without any clean-up step prior to analysis. A linear gradient consisting of (A) water containing 0.1% formic acid and (B) acetonitrile containing 0.1% formic acid, and a ZORBAX SB-Aq column (100 mm × 2.1 mm, 3.5 μm) were employed to obtain the best resolution of the target analytes. The method was validated for linearity, limit of quantification, recovery, matrix effects, precision and stability. Drone pupae samples were found to contain 20E at concentrations of 18.0 ± 0.1 ng/g (mean ± SD) and JH III was detected at concentrations of 0.20 ± 0.06 ng/g (mean ± SD) in queen larvae samples. This validated method provided some practical information for the actual content of JH III and 20E in queen larvae and drone pupae samples.

  18. Sequential oogenesis is controlled by an oviduct factor in the locusts Locusta migratoria and Schistocerca gregaria: Overcoming the doctrine that patency in follicle cells is induced by juvenile hormone.

    PubMed

    Seidelmann, Karsten; Helbing, Cornelia; Göbeler, Norman; Weinert, Heike

    2016-07-01

    In insects that lay eggs in large clutches, yolk accumulation in each of the many ovarioles is restricted to the basal (terminal) oocyte, the one closest to the lateral oviduct. All succeeding (subterminal) oocytes remain small until the terminal oocytes finished their development and were ovulated into the oviduct. The major step regulating yolk uptake by terminal oocytes is the formation of gaps between cells of the follicle layer, a process termed patency. In the migratory as well as in the desert locust, patency is induced by a Patency Inducing Factor (PIF) produced by the lateral oviducts. PIF is secreted in all regions of the lateral oviducts and interacts with the basal follicle cells via the pedicel, a fine duct that connects an ovariole with the oviduct. By this mechanism, patency is triggered in the follicle cells of the terminal oocyte only, restricting yolk accumulation to the oocytes next to ovulation. In contrast to the previous hypothesis, juvenile hormone (JH) is not necessary to induce patency, rather JH amplifies the effect of PIF.

  19. Juvenile Idiopathic Arthritis

    MedlinePlus

    ... Is Juvenile Idiopathic Arthritis the same as Juvenile Rheumatoid Arthritis? Yes, Juvenile Idiopathic Arthritis (JIA) is a new ... of chronic inflammatory diseases that affect children. Juvenile Rheumatoid Arthritis (JRA) is the older term that was used ...

  20. Influence of feeding status, time of the day, and season on baseline adrenocorticotropic hormone and the response to thyrotropin releasing hormone-stimulation test in healthy horses.

    PubMed

    Diez de Castro, E; Lopez, I; Cortes, B; Pineda, C; Garfia, B; Aguilera-Tejero, E

    2014-07-01

    Equine pituitary pars intermedia function can be assessed by the measurement of baseline and thyrotropin releasing hormone (TRH)-induced concentrations of adrenocorticotropic hormone (ACTH); however, these measurements may be affected by the environment. Therefore, a prospective observational study evaluated the influence of feeding, time of the day, and season on baseline and TRH-induced concentrations of ACTH in healthy horses. Baseline ACTH was measured in 50 horses before and 2 h after feeding. Six research horses were subjected to a crossover study in which 6 TRH tests were performed in 2 different seasons, March-April (MA) and July-September (JS), at 2 different times of the day, 8 AM and 8 PM, and, under 2 different conditions relative to feeding status, fasted and 2 h after feeding. Differences between fasted and fed horses were found in baseline ACTH, 17.1 ± 1.8 versus 46.1 ± 7.6 pg/mL (P = 0.003) and TRH-stimulated ACTH: 124.1 ± 21.3 versus 192.6 ± 33.1 pg/mL (P = 0.029) at 10 min, and 40.1 ± 4.9 versus 73.2 ± 13.4 pg/mL (P = 0.018) at 30 min post TRH injection. No differences were found between tests performed at different times of the day. Basal ACTH concentrations were greater in JS than in MA, 17.1 ± 1.8 versus 11.9 ± 0.6 pg/mL (P = 0.006). A seasonal influence was also found in stimulated ACTH values, which were much greater in JS 122.7 ± 36.7 versus 31.2 ± 7.4 pg/mL, at 10 min (P = 0.03) and 39.0 ± 7.2 versus 19.8 ± 3.1 pg/mL, at 30 min (P = 0.03). In addition to season, feeding is a potential confounding factor when measuring baseline or stimulated ACTH in horses. In conclusion, feeding status should be standardized for the diagnosis of equine pituitary pars intermedia dysfunction.

  1. Hormone therapy in acne.

    PubMed

    Lakshmi, Chembolli

    2013-01-01

    Underlying hormone imbalances may render acne unresponsive to conventional therapy. Relevant investigations followed by initiation of hormonal therapy in combination with regular anti-acne therapy may be necessary if signs of hyperandrogenism are present. In addition to other factors, androgen-stimulated sebum production plays an important role in the pathophysiology of acne in women. Sebum production is also regulated by other hormones, including estrogens, growth hormone, insulin, insulin-like growth factor-1, glucocorticoids, adrenocorticotropic hormone, and melanocortins. Hormonal therapy may also be beneficial in female acne patients with normal serum androgen levels. An understanding of the sebaceous gland and the hormonal influences in the pathogenesis of acne would be essential for optimizing hormonal therapy. Sebocytes form the sebaceous gland. Human sebocytes express a multitude of receptors, including receptors for peptide hormones, neurotransmitters and the receptors for steroid and thyroid hormones. Various hormones and mediators acting through the sebocyte receptors play a role in the orchestration of pathogenetic lesions of acne. Thus, the goal of hormonal treatment is a reduction in sebum production. This review shall focus on hormonal influences in the elicitation of acne via the sebocyte receptors, pathways of cutaneous androgen metabolism, various clinical scenarios and syndromes associated with acne, and the available therapeutic armamentarium of hormones and drugs having hormone-like actions in the treatment of acne.

  2. SEX AND OVARIAN HORMONES INFLUENCE VULNERABILITY AND MOTIVATION FOR NICOTINE DURING ADOLESCENCE IN RATS

    PubMed Central

    Lynch, Wendy J.

    2009-01-01

    The purpose of this study was to examine sex differences in sensitivity to nicotine’s reinforcing effects during adolescence, a hormone transition phase characterized by rapid and marked changes in levels of gonadal hormones. Male and female rats were trained to self-administer nicotine (5 or 10 µg/kg/infusion) under a fixed-ratio 1 schedule beginning on postnatal day 30. Following acquisition, responding was assessed under a progressive-ratio schedule until postnatal day 45 with blood sampling occurring prior to the first 5 sessions in order to determine the relationship between gonadal hormones (i.e., estradiol and progesterone in females and testosterone in males) and responding for nicotine. Under low dose conditions, a greater percentage of females than males acquired nicotine self-administration. Under progressive-ratio testing conditions, although adolescent females and males initially responded at similar levels, by the end of the adolescent testing period, females responded at higher levels than males to obtain nicotine infusions. Levels of responding under the progressive-ratio schedule were negatively associated with progesterone and positively associated with the ratio of estradiol to progesterone. These findings demonstrate an enhanced sensitivity in adolescent females as compared to adolescent males to nicotine’s reinforcing effects with evidence implicating circulating hormone levels as modulating this sensitivity. PMID:19619575

  3. Luteinizing hormone secretion as influenced by age and estradiol in the prepubertal gilt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this study was to determine if there is an age related reduction in the sensitivity of the negative feedback action of estradiol on luteinizing hormone (LH) secretion in the prepubertal gilt. Ovariectomized gilts at 90 (n = 12), 150 (n = 11) or 210 (n = 12) days of age received estradiol ...

  4. The Influence of Hormonal Fluctuations on Womens' Selection and Enjoyment of Television Programs.

    ERIC Educational Resources Information Center

    Meadowcroft, Jeanne; Zillmann, Dolf

    Existing theory suggests that women in the premenstrual and menstrual phases of their hormonal cycle would select and enjoy nonarousing television programs, sucy as nonhostile comedy and game shows, and would avoid action drama and hostile and arousing programs. To test this theory, female undergraduates from telecommunications and journalism…

  5. Aging influences steroid hormone release by mink ovaries and their response to leptin and IGF-I.

    PubMed

    Sirotkin, Alexander V; Mertin, Dušan; Süvegová, Karin; Harrath, Abdel Halim; Kotwica, Jan

    2016-01-21

    The aim of our study was to understand whether ovarian steroid hormones, and their response to the metabolic hormones leptin and IGF-I leptin, could be involved in the control of mink reproductive aging via changes in basal release of ovarian progesterone and estradiol. For this purpose, we compared the release of progesterone and estradiol by ovarian fragments isolated from young (yearlings) and old (3-5 years of age) minks cultured with and without leptin and IGF-I (0, 1, 10 or 100 ng/ml). We observed that isolated ovaries of older animals produced less progesterone but not less estradiol than the ovaries of young animals. Leptin addition stimulated estradiol release by the ovarian tissue of young animals but inhibited it in older females. Leptin did not influence progesterone output by the ovaries of either young or older animals. IGF-I inhibited estradiol output in young but not old animals, whereas progesterone release was inhibited by IGF-I irrespective of the animal age. Our observations demonstrate the involvement of both leptin and IGF-I in the control of mink ovarian steroid hormones release. Furthermore, our findings suggest that reproductive aging in minks can be due to (a) reduction in basal progesterone release and (b) alterations in the response of estradiol but not of progesterone to leptin and IGF-I.

  6. Aging influences steroid hormone release by mink ovaries and their response to leptin and IGF-I

    PubMed Central

    Sirotkin, Alexander V.; Mertin, Dušan; Süvegová, Karin; Harrath, Abdel Halim; Kotwica, Jan

    2016-01-01

    ABSTRACT The aim of our study was to understand whether ovarian steroid hormones, and their response to the metabolic hormones leptin and IGF-I leptin, could be involved in the control of mink reproductive aging via changes in basal release of ovarian progesterone and estradiol. For this purpose, we compared the release of progesterone and estradiol by ovarian fragments isolated from young (yearlings) and old (3-5 years of age) minks cultured with and without leptin and IGF-I (0, 1, 10 or 100 ng/ml). We observed that isolated ovaries of older animals produced less progesterone but not less estradiol than the ovaries of young animals. Leptin addition stimulated estradiol release by the ovarian tissue of young animals but inhibited it in older females. Leptin did not influence progesterone output by the ovaries of either young or older animals. IGF-I inhibited estradiol output in young but not old animals, whereas progesterone release was inhibited by IGF-I irrespective of the animal age. Our observations demonstrate the involvement of both leptin and IGF-I in the control of mink ovarian steroid hormones release. Furthermore, our findings suggest that reproductive aging in minks can be due to (a) reduction in basal progesterone release and (b) alterations in the response of estradiol but not of progesterone to leptin and IGF-I. PMID:26794607

  7. Hormonal regulation of lipid metabolism in developing coho salmon, Oncorhynchus kisutch

    SciTech Connect

    Sheridan, M.A.

    1985-01-01

    Lipid metabolism in juvenile coho salmon is characterized, and adaptive changes in lipid mobilization are described in relation to development and hormonal influences. The rates of lipogenesis and lipolysis were determined in selected tissues of juvenile salmon during the period of seawater preadaptive development (smoltification). Neutral lipid (sterol) and fatty acid synthesis in the liver and mesenteric fat was measured by tritium incorporation. Fatty acid synthesis in the liver and mesenteric fat decreased by 88% and 81%, respectively, between late February (parr) and early June (smolt). To assess the role of hormones in smoltification-associated lipid depletion, growth hormone, prolactin, thyroxin and cortisol were administered in vivo early in development (parr) to determine if any of these factors could initiate the metabolic responses normally seen later in development (smolt). Growth hormone stimulated lipid mobilization from coho salmon parr. Prolactin strongly stimulated lipid mobilization in coho parr. Thyroxin and cortisol also stimulated lipid mobilization for coho salmon parr. The direct effect of hormones was studied by in vitro pH-stat incubation of liver slices. These data suggest that norepinephrine stimulates fatty acid release via ..beta..-adrenergic pathways. Somatostatin and its partial analogue from the fish caudal neurosecretory system, urotensin II, also affect lipid mobilization. These results establish the presence of hormone-sensitive lipase in salmon liver and suggest that the regulation of lipid metabolism in salmon involves both long-acting and short-acting hormonal agents.

  8. Factors Affecting Attitudes toward Juvenile Sex Offenders

    ERIC Educational Resources Information Center

    Sahlstrom, Kimberly J.; Jeglic, Elizabeth L.

    2008-01-01

    This study investigated attitudes toward juvenile sex offenders and factors influencing those attitudes. Additionally, the influences of perpetrator characteristics such as age, gender, and ethnicity on societal attitudes towards intervention requirements were also investigated. Overall, attitudes toward juvenile sex offenders and their treatment…

  9. Juvenile hormone biosynthesis and secretion by the female Corpora allata of the larval gypsy moth, Lymantria dispar (L. ) utilizing in vitro organ culture

    SciTech Connect

    Jones, G.L.

    1986-01-01

    Junvenile hormone synthesis and secretion in the female larval gypsy moth was investigated. In vitro culturing methods were developed including: incubating 2 pair of CC-CA gland complexes in 50 ul of osmotically balanced Grace's insect medium containing 1 uCi /sup 3/H-methyl-methionine for 6 hr. JH homologues were identified and quantified using TLC and HPLC. In vitro methods were employed to investigate trends of JH secretion in 4th and ultimate female larval instar CA. Fourth instar CA produced JH peaks of 0.15 pmole/pr/hr between days 2 and 3, but the rate declined to half by day 4. Ultimate instar larvae began secreting 0.48 pmole/pr/hr, but by day 10, had decreased JH output to negligible levels which continued until pupation. Effects upon in vitro JH secretion produced by precocene II and caffeine were examined. Feulgen staining techniques revealed an equal number of cells (30) in 4th and last instar CA. Last instar Ca were 3 times larger than 4th in volume but their actual in vitro JH secretion at peak levels was only 20% greater. In vitro methods demonstrated that JH secretory trends differ in younger versus mature larval instars. Glandular volume increased in last instars but JH secretion was only 20% greater than in 4th's when compared on the basis of volume. Precocene II elicited a negative response on in vivo JH secretion at levels 10 times less than caffeine. Caffeine was judged not to significantly alter JH secretion.

  10. Influence of hormones on the nicotinamide nucleotide coenzymes of adipose tissue

    PubMed Central

    McLean, Patricia; Greenbaum, A. L.; Brown, J.; Greenslade, K. R.

    1967-01-01

    The concentrations of the oxidized and reduced forms of the nicotinamide nucleotides were measured in the epididymal fat pads of normal, alloxan-diabetic and hypophysectomized rats. In both alloxan-diabetic rats and hypophysectomized rats the weight of the adipose tissue fell, as did the total content of NADH and NADPH; in addition, NAD+ was decreased in the alloxan-diabetic group. Of these changes the most marked was in NADPH and this was the only significant difference when the results were expressed as nicotinamide nucleotides/mg. of tissue protein. The concentration of NADPH in the hypophysectomized rats was not altered by treatment with growth hormone but was restored to normal by treatment with thyroxine. These results are discussed in relation to the known effect of these hormonal conditions on lipid synthesis in adipose tissue. PMID:16742525

  11. Sex and stress hormone influences on the expression and activity of brain-derived neurotrophic factor.

    PubMed

    Carbone, D L; Handa, R J

    2013-06-03

    The neurotrophin, brain-derived neurotrophic factor (BDNF), is recognized as a key component in the regulation of CNS ontogeny, homeostasis and adult neuroplasticity. The importance of BDNF in CNS development and function is well documented by numerous reports from animal studies linking abnormal BDNF signaling to metabolic disturbances and anxiety or depressive-like behavior. Despite the diverse roles for BDNF in nearly all aspects of CNS physiology, the regulation of BDNF expression, as well as our understanding of the signaling mechanisms associated with this neurotrophin, remains incomplete. However, links between sex hormones such as estradiol and testosterone, as well as endogenous and synthetic glucocorticoids (GCs), have emerged as important mediators of BDNF expression and function. Examples of such regulation include brain region-specific induction of Bdnf mRNA in response to estradiol. Additional studies have also documented regulation of the expression of the high-affinity BDNF receptor Tropomyosin-Related Kinase B by estradiol, thus implicating sex steroids not only in the regulation of BDNF expression, but also in mechanisms of signaling associated with it. In addition to gonadal steroids, further evidence also suggests functional interaction between BDNF and GCs, such as in the regulation of corticotrophin-releasing hormone and other important neuropeptides. In this review, we provide an overview of the roles played by selected sex or stress hormones in the regulation of BDNF expression and signaling in the CNS.

  12. Hormone levels

    MedlinePlus

    Blood or urine tests can determine the levels of various hormones in the body. This includes reproductive hormones, thyroid hormones, adrenal hormones, pituitary hormones, and many others. For more information, see: ...

  13. Juvenile Spondyloarthritis

    PubMed Central

    Gmuca, Sabrina; Weiss, Pamela F.

    2015-01-01

    Purpose of review To provide a comprehensive update of the pathogenesis, diagnostic imaging, treatments, and disease activity measurements of juvenile spondyloarthritis (JSpA). Recent findings Genetic and microbiome studies have provided new information regarding possible pathogenesis of JSpA. Recent work suggests that children with JSpA have decreased thresholds for pain in comparison to healthy children. Additionally, pain on physical examination and abnormalities on ultrasound of the entheses are not well correlated. Treatment guidelines for juvenile arthritis, including JSpA, were published by the American College of Rheumatology and are based on active joint count and presence of sacroiliitis. Recent studies have established the efficacy of tumor necrosis factor inhibitors in the symptomatic treatment of axial disease, though their efficacy for halting progression of structural damage is less clear. Newly developed disease activity measures for JSpA include the Juvenile Arthritis Disease Activity Score and the JSpA Disease Activity index. In comparison to other categories of juvenile arthritis, children with JSpA are less likely to attain and sustain inactive disease. Summary Further microbiome and genetic research may help elucidate JSpA pathogenesis. More randomized therapeutic trials are needed and the advent of new composite disease activity measurement tools will hopefully allow for the design of these greatly needed trials. PMID:26002028

  14. Influence of inter-set stretching on strength, flexibility and hormonal adaptations.

    PubMed

    Souza, Antônio Claudio; Bentes, Claudio Melibeu; de Salles, Belmiro Freitas; Reis, Victor Machado; Alves, José Vilaça; Miranda, Humberto; Novaes, Jefferson da Silva

    2013-03-01

    Adequate levels of strength and flexibility are important for the promotion and maintenance of health and functional autonomy as well as safe and effective sports participation. The aim of the present study was to analyze the effects of 8 weeks of strength training with or without inter-set static stretching on strength, flexibility and hormonal adaptations of trained men. Sixteen trained men were randomly divided into 2 groups: the static stretching group (SSG) and passive interval group (PIG). All participants performed 24 training sessions 3 times a week. The test and retest of 8RM, strength, flexibility, cortisol and growth hormone concentration in pre and post test conditions were also evaluated. To compare the differences between and within groups in pre- and post-training tests, ANOVA with repeated measures was performed (SSGpre x SSGpost; PIGpre x PIGpost; SSGpost x PIGpost). An alpha level of p<0.05 was considered statistically significant for all comparisons. Both groups showed significant increases in strength (SSGpre vs. SSGpost; PIGpre vs. PIGpost) in the same exercises for leg extension (LE) and Low Row (LR). Specifically, in the SSG group, the parameters for LE were (p = 0.0015 and ES = 2.28 - Large), and the parameters for LR were (p = 0.002 and ES = 1.95 - Large). Moreover, in the PIG group, the parameters for LE were (p = 0.009 and ES = 1.95 - Large), and the parameters for LR were (p = 0.0001 and ES = 2.88 - Large). No differences were found between the groups (SSGpost vs. PIGpost). Both groups showed significant increases in flexibility but in different joints (SSGpre vs. SSGpost; PIGpre vs. PIGpost). In the SSG group, only three joints showed significant increases in flexibility: shoulder extension (p = 0.004 and ES = 1.76 - Large), torso flexion (p = 0.002 and ES = 2.36 - Large), and hip flexion (p = 0.001 and ES = 1.79 -Large). In the PIG group, only three joints showed increases in flexibility: horizontal shoulder abduction (p = 0.003 and ES

  15. Short neuropeptide F (sNPF) is a stage-specific suppressor for juvenile hormone biosynthesis by corpora allata, and a critical factor for the initiation of insect metamorphosis.

    PubMed

    Kaneko, Yu; Hiruma, Kiyoshi

    2014-09-15

    Molting and metamorphosis are essential events for arthropod development, and juvenile hormone (JH) and its precursors play critical roles for these events. We examined the regulation of JH biosynthesis by the corpora allata (CA) in Bombyx mori, and found that intact brain-corpora cardiaca (CC)-CA complexes produced a smaller amount of JH than that in CC-CA complexes and CA alone throughout the 4th and 5th (last) instar stadium. The smaller amount of synthesis was due to allatostatin-C (AST-C) produced by the brain. The CC synthesized short neuropeptide F (sNPF) that also suppressed the JH synthesis, but only in day 3 4th stadium and after the last larval ecdysis. For the suppression, both peptides prevented the expression of some of the distinct JH biosynthetic enzymes in the mevalonate pathway. Allatotropin (AT) stimulated sNPF expression in the CC of day 1 5th instar stadium, not of day 3 4th; therefore the stage-specific inhibition of JH synthesis by sNPF was partly due to the stimulative action of AT on the sNPF expression besides the stage-specific expression of the sNPF receptors in the CA, the level of which was high in day 2 4th and day 0 5th instar larvae. The cessation of JH biosynthesis in the last instar larvae is a key event to initiate pupal metamorphosis, and both sNPF and AST-C are key factors in shutting down JH synthesis, along with the decline of ecdysone titer and dopamine.

  16. Juvenile hormone titers in virgin and mated Choristoneura fumiferana and C. rosaceana females: assessment of the capacity of males to produce and transfer JH to the female during copulation.

    PubMed

    Cusson, M; Delisle, J; Miller, D

    1999-07-01

    We used a radioimmunoassay (RIA) to assess the effect of mating on juvenile hormone (JH) titer in females of the tortricid moths Choristoneura fumiferana and C. rosaceana. Virgins had undetectable levels of JH in their hemolymph on the 5th day of the pupal stage but titers rose to 1-4 and 0.2-0.5 ng JH II eq./ml, respectively, after emergence. On days 1, 3 and 5 following copulation, females of both species had higher JH titers than virgins of the same ages, with the greatest difference between virgin and mated females observed on day 3 for C. fumiferana and on day 5 for C. rosaceana. This increase was apparently not the result of a male-to-female transfer of JH during copulation since: (i) the accessory sex glands (ASGs) of males of both species displayed a very limited ability to convert JH acid into JH, (ii) ASGs produced no JH when incubated in vitro in the presence of L-[methyl-(3)H]-methionine, (iii) ASGs of males injected with L-[methyl-(3)H]-methionine 24 h prior to dissection contained no JH-associated radioactivity, and (iv) freshly formed spermatophores dissected out of females mated to similarly injected males contained no trace of radioactive JH. In addition, the JH content of ASGs and spermatophores, as measured by RIA, was not higher than that of virgin-female hemolymph, on a per-mg basis. However, in contrast with earlier findings in other species of moths, the CA of male C. fumiferana and C. rosaceana maintained in vitro in the presence of tritiated methionine produced and released JH I, JH II and JH III in quantities and proportions similar to those reported for female glands.

  17. Does macroalgal vegetation cover influence post-settlement survival and recruitment potential of juvenile black rockfish Sebastes cheni?

    NASA Astrophysics Data System (ADS)

    Kamimura, Yasuhiro; Shoji, Jun

    2013-09-01

    Seasonal change in vegetation coverage affected cohort-specific mortality of post-settlement juvenile black rockfish Sebastes cheni in a temperate macroalgal bed. A total of 14 fish and environmental surveys were conducted at an interval of one to two weeks from February to May, 2008 in the central Seto Inland Sea, southwestern Japan. The birth date of S. cheni was estimated by use of the otolith daily rings and then fish were divided into 7 cohorts (A to F), each covering a 7-day birth date period. Cohort-specific growth coefficient (G, d-1) of juvenile S. cheni from 20 to 60 mm in total length (TL) ranged between 0.031 and 0.048 and mortality coefficient (M, d-1) between 0.038 and 0.081, with significant increases in both values as the season progressed. The ratio of G:M, which is a proxy of the recruitment potential, ranged between 0.59 and 0.99 and was lower in later cohorts. Water temperature increased from 10.9 °C in March to 18.2 °C in May and vegetation coverage (bulk volume of Sargassum spp., %: as an index of the function for predation refuge) decreased from 60% in March to 2% in May. The later cohorts of juvenile S. cheni had high growth and mortality rates related to high temperature and low vegetation coverage. Since the seasonal increase in M was greater than that of G, the recruitment potential of the later cohorts was lower than that of the earlier cohorts.

  18. Influence of a twelve-month conditioning program on physical growth, serum hormones, and neuromuscular performance of peripubertal male fencers.

    PubMed

    Tsolakis, Charilaos K; Bogdanis, Gregory C; Vagenas, George K; Dessypris, Athanasios G

    2006-11-01

    This study examined the effects of a typical fencing training program on selected hormones, neuromuscular performance, and anthropometric parameters in peripubertal boys. Two sets of measurements, before training and after 12 months of training, were performed on 2 groups of 11- to 13-year-old boys. One group consisted of fencers (n = 8), who trained regularly for the 12-month period, and the other group (n = 8) consisted of inactive children of the same age. There was no difference in Tanner's maturation stage of the 2 groups before (controls, 2.5 +/- 0.3; fencers, 2.1 +/- 0.3) and after the 12 months (controls, 3.0 +/- 0.3; fencers, 3.0 +/- 0.3). Serum testosterone, growth hormone, sex hormone binding globulin, free androgen index, and leptin changed significantly over time, reaching similar values in the 2 groups at the end of the study. Significantly greater increases in body mass (16 +/- 3%) and leg cross-sectional area (CSA) (32 +/- 7%) were observed only in the fencers' group, and these differences disappeared when height was set as a changing covariate. Although there was a greater increase in height for the fencers compared to the control group (8.6 +/- 1.2 vs. 3.6 +/- 0.9 cm, p < 0.01), the height reached at the end of the study was almost identical in the 2 groups (controls, 163.6 +/- 5.1; fencers, 165.4 +/- 2.8). Arm CSA, handgrip strength, and vertical jump performance changed significantly over time for both groups, with no differences between groups. It was concluded that a typical fencing training program for peripubertal boys did not have any effect on selected growth and anabolic hormones and did not influence the normal growth process, as this was reflected by changes in selected anthropometric and neuromuscular performance parameters. This may be because of the characteristics of the present fencing training program, which may not be adequate to alter children's hormonal functions in such a way as to override the rapid changes occurring during

  19. The Influence of a 12-Week Conditioning Program on Growth Hormone and Somatomedin C Concentrations in Moderately Overweight Males.

    ERIC Educational Resources Information Center

    Kinard, James D.; Bazzarre, Terry L.

    The growth hormone is a lipolytic hormone and somatomedin C mediates the metabolic effects of the growth hormone in many tissues. Growth hormone plasma levels are often depressed in obese individuals, and this low plasma level has been postulated as a reason for perpetuation of excess weight. Substantial weight loss in obese subjects improves…

  20. The influence of intrauterine exposure to immunosuppressive treatment on changes in the immune system in juvenile Wistar rats

    PubMed Central

    Kabat-Koperska, Joanna; Kolasa-Wołosiuk, Agnieszka; Wojciuk, Bartosz; Wojciechowska-Koszko, Iwona; Roszkowska, Paulina; Krasnodębska-Szponder, Barbara; Paczkowska, Edyta; Safranow, Krzysztof; Gołembiewska, Edyta; Machaliński, Bogusław; Ciechanowski, Kazimierz

    2016-01-01

    Background In our study, we assessed the impact of immunosuppressive drug combinations on changes in the immune system of juvenile Wistar rats exposed to these drugs during pregnancy. We primarily concentrated on changes in two organs of the immune system – the thymus and the spleen. Methods The study was conducted on 40 (32+8) female Wistar rats administered full and half dose of drugs, respectively, subjected to regimens commonly used in therapy of human kidney transplant recipients ([1] cyclosporine A, mycophenolate mofetil, and prednisone; [2] tacrolimus, mycophenolate mofetil, and prednisone; [3] cyclosporine A, everolimus, and prednisone). The animals received drugs by oral gavage 2 weeks before pregnancy and during 3 weeks of pregnancy. Results There were no statistically significant differences in the weight of the thymus and spleen, but changes were found in the results of blood hematology, cytometry from the spleen, and a histologic examination of the examined immune organs of juvenile Wistar rats. In the cytokine assay, changes in the level of interleukine 17 (IL-17) after increasing amounts of concanavaline A were dose-dependent; the increase of IL-17 was blocked after administration of higher doses of immunosuppressive drugs. However, after a reduction of doses, its increase resumed. Conclusion Qualitative, quantitative, and morphological changes in the immune system of infant rats born to pharmacologically immunosuppressed females were observed. Thymus structure, spleen composition, and splenocyte IL-17 production were mostly affected in a drug regimen–dependent manner. PMID:27471376

  1. Influence of Incision Location on Transmitter Loss, Healing, Survival, Growth, and Suture Retention of Juvenile Chinook Salmon

    SciTech Connect

    Panther, Jennifer L.; Brown, Richard S.; Gaulke, Greg L.; Deters, Katherine A.; Woodley, Christa M.; Eppard, M. Brad

    2011-11-01

    Fisheries research involving surgical implantation of transmitters necessitates the use of methods that minimize transmitter loss and fish mortality and optimize healing of the incision. We evaluated the effects of three incision locations on transmitter loss, healing, survival, growth, and suture retention in juvenile Chinook salmon Oncorhynchus tshawytscha. The three incision locations were (1) on the linea alba (LA incision), (2) adjacent and parallel to the LA (muscle-cutting [MC] incision), and (3) extending from the LA towards the dorsum at a 45° angle, between the parallel lines of myomeres (muscle-sparing [MS] incision). A Juvenile Salmon Acoustic Telemetry System acoustic transmitter (0.44 g in air) and a passive integrated transponder tag (0.10 g in air) were implanted into each fish (total N = 936 fish). The fish were held at 12°C or 20°C and were examined weekly for 98 d. The progression of healing among incision locations and the variability in transmitter loss made it difficult to identify one incision location as the best choice. The LA incisions had a much smaller wound extent (area of visible subepidermal tissue) than MC and MS incisions during the first 28 d of the study. In both temperature treatments, apposition of incisions through day 14 was better for LA incisions than for MC and MS incisions. However, MC and MS incisions were less likely than LA incisions to reopen over time and thus were less likely to allow transmitter loss through the incision.

  2. Influence of Incision Location on Transmitter Loss, Healing, Incision Lengths, Suture Retention, and Growth of Juvenile Chinook Salmon

    SciTech Connect

    Panther, Jennifer L.; Brown, Richard S.; Gaulke, Greggory L.; Woodley, Christa M.; Deters, Katherine A.

    2010-05-11

    In this study, conducted by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District, we measured differences in survival and growth, incision openness, transmitter loss, wound healing, and erythema among abdominal incisions on the linea alba, lateral and parallel to the linea alba (muscle-cutting), and following the underlying muscle fibers (muscle-sparing). A total of 936 juvenile Chinook salmon were implanted with both Juvenile Salmon Acoustic Tracking System transmitters (0.43 g dry) and passive integrated transponder tags. Fish were held at 12°C (n = 468) or 20°C (n = 468) and examined once weekly over 98 days. We found survival and growth did not differ among incision groups or between temperature treatment groups. Incisions on the linea alba had less openness than muscle-cutting and muscle-sparing incisions during the first 14 days when fish were held at 12°C or 20°C. Transmitter loss was not different among incision locations by day 28 when fish were held at 12°C or 20°C. However, incisions on the linea alba had greater transmitter loss than muscle-cutting and muscle-sparing incisions by day 98 at 12°C. Results for wound closure and erythema differed among temperature groups. Results from our study will be used to improve fish-tagging procedures for future studies using acoustic or radio transmitters.

  3. Influence of multiple dam passage on survival of juvenile Chinook salmon in the Columbia River estuary and coastal ocean

    PubMed Central

    Rechisky, Erin L.; Welch, David W.; Porter, Aswea D.; Jacobs-Scott, Melinda C.; Winchell, Paul M.

    2013-01-01

    Multiple dam passage during seaward migration is thought to reduce the subsequent survival of Snake River Chinook salmon. This hypothesis developed because juvenile Chinook salmon from the Snake River, the Columbia River’s largest tributary, migrate >700 km through eight hydropower dams and have lower adult return rates than downstream populations that migrate through only 3 or 4 dams. Using a large-scale telemetry array, we tested whether survival of hatchery-reared juvenile Snake River spring Chinook salmon is reduced in the estuary and coastal ocean relative to a downstream, hatchery-reared population from the Yakima River. During the initial 750-km, 1-mo-long migration through the estuary and coastal ocean, we found no evidence of differential survival; therefore, poorer adult returns of Snake River Chinook may develop far from the Columbia River. Thus, hydrosystem mitigation efforts may be ineffective if differential mortality rates develop in the North Pacific Ocean for reasons unrelated to dam passage. PMID:23576733

  4. The emergence of gonadal hormone influences on dopaminergic function during puberty.

    PubMed

    Kuhn, Cynthia; Johnson, Misha; Thomae, Alex; Luo, Brooke; Simon, Sidney A; Zhou, Guiying; Walker, Q David

    2010-06-01

    Adolescence is the developmental epoch during which children become adults-intellectually, physically, hormonally and socially. Brain development in critical areas is ongoing. Adolescents are risk-taking and novelty-seeking and they weigh positive experiences more heavily and negative experiences less than adults. This inherent behavioral bias can lead to risky behaviors like drug taking. Most drug addictions start during adolescence and early drug-taking is associated with an increased rate of drug abuse and dependence. The hormonal changes of puberty contribute to physical, emotional, intellectual and social changes during adolescence. These hormonal events do not just cause maturation of reproductive function and the emergence of secondary sex characteristics. They contribute to the appearance of sex differences in non-reproductive behaviors as well. Sex differences in drug use behaviors are among the latter. The male predominance in overall drug use appears by the end of adolescence, while girls develop the rapid progression from first use to dependence (telescoping) that represent a female-biased vulnerability. Sex differences in many behaviors including drug use have been attributed to social and cultural factors. A narrowing gap in drug use between adolescent boys and girls supports this thesis. However, some sex differences in addiction vulnerability reflect biologic differences in brain circuits involved in addiction. The purpose of this review is to summarize the contribution of sex differences in the function of ascending dopamine systems that are critical to reinforcement, to briefly summarize the behavioral, neurochemical and anatomical changes in brain dopaminergic functions related to addiction that occur during adolescence and to present new findings about the emergence of sex differences in dopaminergic function during adolescence.

  5. The Influence of Hormonal Contraception on Mood and Sexual Interest among Adolescents

    PubMed Central

    Ott, Mary A.; Shew, Marcia L.; Ofner, Susan; Tu, Wanzhu; Fortenberry, J. Dennis

    2010-01-01

    Mood and sexual interest changes are commonly cited reasons for discontinuing hormonal contraceptives. Data, however, are inconsistent and limited to adult users. We examined associations of hormonal contraceptive use with mood and sexual interest among adolescents. We recruited 14-17 year old women primary care clinics and followed them longitudinally for up to 41 months. Participants completed face-to-face interviews quarterly and two 12 week periods of daily diary collection per year. On daily diaries, participants recorded positive mood, negative mood, and sexual interest. We classified 12 week diary periods as “stable OCP use,” “non-use,” “initiated use,” “stopped use,” and “DMPA use” based on self-report of oral contraceptive pill (OCP) use and depot medroxyprogesterone acetate (DMPA) use from medical charts. Diary periods were the unit of analysis. Participants could contribute more than one diary period. We analyzed data using linear models with a random intercept and slope across weeks in a diary period, an effect for contraceptive group, and an adjustment for age at the start of a diary period. Mean weekly positive mood was higher in diary periods characterized by stable OCP use, compared to other groups. Mean weekly negative mood was lower in diary periods characterized by stable OCP use and higher in periods characterized by DMPA use. Periods characterized by stable OCP use additionally showed less mood variation than other groups. Changes in mood among adolescent hormonal contraceptive users differed from those anticipated for adult users. Attention to adolescent-specific changes in mood and sexual interest may improve contraceptive adherence. PMID:18288601

  6. Juvenile morphology in baleen whale phylogeny

    NASA Astrophysics Data System (ADS)

    Tsai, Cheng-Hsiu; Fordyce, R. Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  7. Juvenile morphology in baleen whale phylogeny.

    PubMed

    Tsai, Cheng-Hsiu; Fordyce, R Ewan

    2014-09-01

    Phylogenetic reconstructions are sensitive to the influence of ontogeny on morphology. Here, we use foetal/neonatal specimens of known species of living baleen whales (Cetacea: Mysticeti) to show how juvenile morphology of extant species affects phylogenetic placement of the species. In one clade (sei whale, Balaenopteridae), the juvenile is distant from the usual phylogenetic position of adults, but in the other clade (pygmy right whale, Cetotheriidae), the juvenile is close to the adult. Different heterochronic processes at work in the studied species have different influences on juvenile morphology and on phylogenetic placement. This study helps to understand the relationship between evolutionary processes and phylogenetic patterns in baleen whale evolution and, more in general, between phylogeny and ontogeny; likewise, this study provides a proxy how to interpret the phylogeny when fossils that are immature individuals are included. Juvenile individuals in the peramorphic acceleration clades would produce misleading phylogenies, whereas juvenile individuals in the paedomorphic neoteny clades should still provide reliable phylogenetic signals.

  8. The influence of photoperiod on body weight gain, body composition, nutrient intake and hormone secretion.

    PubMed

    Tucker, H A; Petitclerc, D; Zinn, S A

    1984-12-01

    Increasing daily light exposure from 8 to 16 h increases average daily body weight gains of sheep and Holstein cattle but reduces gains of white-tailed doe fawns. Some of these effects on average daily gain in sheep are the result of increased gut fill and pelt weight. Increasing daily exposure to light increases feed intake when sheep or cattle are fed ad libitum. However, increased feed intake is not a prerequisite for the anabolic effects of long duration exposures to light because increased growth occurs in the animals given 16 h light:8 h dark (16L:8D) even when feed intake is restricted. The anabolic effects of increased duration photoperiods in sheep are independent of the gonads, whereas in cattle they are dependent on the gonads. Consistent increases in average daily gains of cattle in response to longer duration photoperiods have not always been achieved. The lack of consistency may be associated with sexual maturity or rate of fattening of the animal. For example, the stimulatory effects of 16L:8D photoperiods on live weight gain are not readily manifested in immature prepubertal heifers, but occur primarily during the peripubertal period. Short days are conducive to deposition of fat, which may account for the stimulatory effects of short days on live weight gain of white-tailed doe fawns and excessively fattened Holsteins. In contrast, long duration photoperiods stimulate protein accretion in cattle. The hormonal signals that mediate the anabolic effects of increasing exposure to light are not associated with change in insulin, thyroxine or growth hormone concentrations in the blood. Glucocorticoid concentrations in serum decrease with longer duration photoperiods which is consistent with an anabolic effect. Increasing daily light exposure to 16 h/d hastens the increase in concentrations of progesterone and testosterone in sera of peripubertal heifers and prepubertal bulls, respectively. Thus, change in secretion of reproductive hormones in the

  9. Hormonal influences in prostate cancer: an update of a complex subject.

    PubMed

    Biundo, Bruce

    2010-01-01

    Pharmacists who are involved with patients and physicians have a tremendous opportunity to serve in the realm of prostate cancer, and there are numerous compounding opportunities. For example, compounded testosterone gels can help keep testosterone levels in the mid to upper range with proper dosing and patient counseling. Also, estradiol levels can be held in check or lowered by compounding aromatase-inhibitors such as anastrazole or letrazole into the lower doses that men require, rather than their more potent versions for female patients. Nutraceuticals such as omega-3 fatty acids, vitamin D, zinc, and selenium all play an important role in prostate health, as these agents have 5a-reductase inhibiting and anti-inflammatory properties. More than anything else, we see that the pathophysiology of prostate cancer, although quite complex, is being explored at an amazing rate. The author believes that hormonal balance is critical, and that it is largely hormonal imbalance that is involved in prostate disease. In that regard, the author concludes that the levels of testosterone, estradiol, and drotestosterone, experienced at a more youthful age are vital if we are to improve prostate health.

  10. Thyroid hormone balance in beluga whales, Delphinapterus leucas: dynamics after capture and influence of thyrotropin.

    PubMed Central

    St Aubin, D J; Geraci, J R

    1992-01-01

    Ten beluga whales, Delphinapterus leucas, were captured in the Churchill River, Manitoba, held for up to five days, and then released. Blood samples were obtained immediately after capture and at 6-7 h intervals thereafter to monitor changes in circulating levels of thyroid hormones (TH). In six of the whales, total and free thyroxine (T4) and triiodothyronine (T3) declined steadily, whereas reverse-T3 (rT3) showed a transient increase during the first 24-36 h, followed by a decrease to below initial values. The changes in TH may have been due to glucocorticoid-mediated reduction in endogenous thyroid stimulating hormone (TSH), and inhibition of 5'-monodeiodinase in peripheral tissue. Two whales were given 10 IU of bovine TSH immediately after capture, and again one and two days later, resulting in successive increases in all TH, which remained elevated for at least 24 h after the last injection. Thereafter, circulating levels declined as in the untreated whales. Two whales receiving a single TSH injection on the fourth day responded with an increase in plasma TH comparable to that observed following the first TSH injection in the other two animals. Average (+/- SD) circulating level of rT3 at capture was 6.3 +/- 3.1 nmol/L, which is higher than reported for any other mammal and was significantly correlated with the naturally elevated levels of T4 that occur in belugas occupying estuaries during the summer. PMID:1586888

  11. Under a neighbour's influence: public information affects stress hormones and behaviour of a songbird.

    PubMed

    Cornelius, Jamie M; Breuner, Creagh W; Hahn, Thomas P

    2010-08-07

    Socially acquired information improves the accuracy and efficiency of environmental assessments and can increase fitness. Public information may be especially useful during unpredictable food conditions, or for species that depend on resources made less predictable by human disturbance. However, the physiological mechanisms by which direct foraging assessments and public information are integrated to affect behaviour remain largely unknown. We tested for potential effects of public information on the behavioural and hormonal response to food reduction by manipulating the social environment of captive red crossbills (Loxia curvirostra). Red crossbills are irruptive migrants that are considered sensitive to changes in food availability and use public information in decision making. Here, we show that public information can attenuate or intensify the release of glucocorticoids (i.e. stress hormones) during food shortage in red crossbills. The observed modulation of corticosterone may therefore be a physiological mechanism linking public information, direct environmental assessments and behavioural change. This mechanism would not only allow for public information to affect individual behaviour, but might also facilitate group decision making by bringing group members into more similar physiological states. The results further suggest that stressors affecting entire populations may be magnified in individual physiology through social interactions.

  12. An evaluation of the influence of substrate on the response of juvenile freshwater mussels (fatmucket, Lampsilis siliquoidea) in acute water exposures to ammonia

    USGS Publications Warehouse

    Miao, J.; Barnhart, M.C.; Brunson, E.L.; Hardesty, D.K.; Ingersoll, C.G.; Wang, N.

    2010-01-01

    Acute 96-h ammonia toxicity to three-month-old juvenile mussels (Lampsilis siliquoidea) was evaluated in four treatments (water-only, water-only with feeding, water and soil, and water and sand) using an exposure unit designed to maintain consistent pH and ammonia concentrations in overlying water and in pore water surrounding the substrates. Median effect concentrations (EC50s) for total ammonia nitrogen in the four treatments ranged from 5.6 to 7.7mg/L and median lethal concentrations (LC50s) ranged from 7.0 to 11mg/L at a mean pH of 8.4. Similar EC50s or LC50s with overlapping 95% confidence intervals among treatments indicated no influence of substrate on the response of mussels in acute exposures to ammonia. ?? 2010 SETAC.

  13. Juvenile Justice in Milwaukee

    ERIC Educational Resources Information Center

    Williams, Gary L.; Greer, Lanetta

    2010-01-01

    Historically, there have been several attempts made to address issues surrounding juvenile delinquency. The Wisconsin Legislature outlines the objectives of the juvenile justice system in the Juvenile Justice Code in s. 939.01, ?to promote a juvenile justice system capable of dealing with the problem of juvenile delinquency, a system which will…

  14. Development of an LC-MS/MS method to quantify sex hormones in bovine milk and influence of pregnancy in their levels.

    PubMed

    Regal, P; Cepeda, A; Fente, C

    2012-01-01

    Hormones work in harmony in the body, and this status must be maintained to avoid metabolic disequilibrium and the subsequent illness. Besides, it has been reported that exogenous steroids (presence in the environment and food products) influence the development of several important illnesses in humans. Endogenous steroid hormones in food of animal origin are unavoidable as they occur naturally in these products. The presence of hormones in food has been connected with several human health problems. Bovine milk contains considerable quantities of hormones and it is of particular concern. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, based on hydroxylamine derivatisation, has been developed and validated for the quantification of six sex hormones in milk [pregnenolone (P₅), progesterone (P₄), estrone (E₁), testosterone (T), androstenedione (A) and dehydroepiandrosterone (DHEA)]. This method has been applied to real raw milk samples and the existence of differences between milk from pregnant and non-pregnant cows has been statistically confirmed. Basing on a revision of existing published data, it could be concluded that maximum daily intakes for hormones are not reached through milk ingestion. Although dairy products are an important source of hormones, other products of animal origin must be considered as well for intake calculations.

  15. Influence of blood collection in plastic vs. glass evacuated serum-separator tubes on hormone and tumour marker levels.

    PubMed

    Smets, Eva M L; Dijkstra-Lagemaat, Josien E; Blankenstein, Marinus A

    2004-04-01

    Introduction of preanalytical automation in our laboratory required the use of plastic blood collection tubes. Because of possible interference caused by adsorption of components to the plastic wall and because there is virtually no literature on this subject, we investigated the influence of collection of serum in plastic tubes on the results of nearly all our immunoassays for hormones and tumour markers. Blood from healthy volunteers was collected simultaneously in glass and plastic tubes, or sera prepared from blood collected in glass tubes were brought into the plastic tubes under investigation. Hormone and tumour marker levels were measured in the pairs thus obtained. Results were analysed using paired t-tests or Wilcoxon signed rank tests. We found small but statistically significant differences (p<0.05) between glass and plastic for free triiodothyronine, progesterone, prolactin, prostate-specific antigen and pregnancy-associated plasma protein-A. Non-significant trends (0.05

  16. Tagging Juvenile Pacific Lamprey with Passive Integrated Transponders: Methodology, Short-Term Mortality, and Influence on Swimming Performance

    SciTech Connect

    Mueller, Robert P.; Moursund, Russell A.; Bleich, Matthew D.

    2006-05-31

    Populations of Pacific lamprey (Lampetra tridentata) in the Columbia River basin have declined drastically over the past 20 years. Possible causes include habitat degradation and instream flow obstacles, such as the mainstem hydroelectric dams on the Columbia River. To determine why lamprey populations have declined a monitoring system to track their movements was needed to determine possible impacts. Juvenile lamprey were implanted with passive integrated transponder (PIT) tags and their detection rates determined while migrating through fish bypass facilities at McNary in 2001 and 2005 and John Day Dam in 2002. Juvenile Pacific lamprey (115–178 mm) were obtained from the John Day Dam fish collection facility, transported to Pacific Northwest National Laboratory, and surgically PIT-tagged. Lamprey were allowed to recover for 3 to 4 days following PIT tag implantation and subsequently were released upstream of the PIT tag detectors at both dams. Primary detector efficiency was 98% at McNary Dam and 97% at John Day Dam. Average in-river travel time for fish released at McNary Dam and detected at John Day Dam was 16.1 d in 2001 and 10 d in 2005. Mean detection rates at McNary Dam varied from 74% for gatewell releases to 69% for the collection channel. Follow up tests in 2005 at McNary Dam showed detections rates near 100% from collection channel releases. Detection rates from forebay releases at McNary Dam were lower, ranging from 0% to 38% (mean = 21%). Mean travel times from release point to the primary detectors at McNary Dam were; forebay (492 min), gatewell (323 min), and collection channel (245 min). The detection efficiency at the primary detectors was similar to that of PIT-tagged smolts and travel time within the bypass system showed that lamprey can hold in the bypass system for prolonged periods.

  17. Tagging Juvenile Pacific Lamprey with Passive Integrated Transponders: Methodology, Short-Term Mortality, and Influence on Swimming Performance

    SciTech Connect

    Mueller, Robert P.; Moursund, Russell A.; Bleich, Matthew D.

    2006-05-01

    This study was conducted to determine the feasibility (i.e., efficiency and onintrusiveness) of tagging juvenile Pacific lampreys Lampetra tridentata with passive integrated transponder (PIT) tags and to determine any associated impacts on survivorship and swimming ability. Juvenile Pacific lampreys were obtained from the John Day Dam fish collection facility and tests were conducted at the Pacific Northwest National Laboratory in 2001 and 2002. A new PIT-tagging procedure was used to inject 12-mm tags 5 mm posterior to the gill openings. ampreys were allowed to recover for 3–4 d following surgery before postmortality and swimming tests were conducted. The PIT tagging procedure during 2001 did not include a suture, and 2.6% of the tags were shed after 40 d. During 2002 a single suture was used to close the opening after inserting a tag, and no tag shedding was observed. Overall short-term mortality rates for lampreys 120–155 mm (total length) held for 40 d at 88C was 2.2% for tagged and 2.7% for untagged fish. Mortality increased significantly when tagged and untagged groups were held in warmer (19–238C) river water: 50% for tagged and 60% for untagged animals. Lengths did not significantly affect survival for either the tagged or untagged group held in warm water. A fungal infection was observed to be the cause of death when water temperature increased. Swimming tests to determine any adverse effects due to tag insertion showed no significant difference (P ¼ 0.12) between tagged and untagged lampreys for mean burst speed; however, maximum burst speeds were significantly lower for the PIT-tagged group.

  18. Influence of microbial diversity and plant growth hormones in compost and vermicompost from fermented tannery waste.

    PubMed

    Ravindran, Balasubramani; Wong, Jonathan W C; Selvam, Ammaiyappan; Sekaran, Ganesan

    2016-10-01

    This study focuses on the effect of the epigeic earthworm Eudrilus eugeniae (with and without addition) to transform solid state fermented (SSF) and submerged (SmF) state fermented TFL mixed with cow dung and leaf litter into value added products in compost and vermicompost bioreactors respectively. The significant role of microbes was identified during compost and vermicompost process. In addition, three important phytohormones (Indole 3-acetic acid, Gibberellic acid, Kinetin) were also detected in the compost and vermicompost products. The results revealed that the maximum amount of plant hormones were available in the vermicompost products which may be due to the joint action of earthworm and microorganisms. The overall results confirmed that the vermicomposting process produced a greater value added product.

  19. Balance between salt stress and endogenous hormones influence dry matter accumulation in Jerusalem artichoke.

    PubMed

    Shao, Tianyun; Li, Lingling; Wu, Yawen; Chen, Manxia; Long, Xiaohua; Shao, Hongbo; Liu, Zhaopu; Rengel, Zed

    2016-10-15

    Salinity is one of the most serious environmental stresses limiting agricultural production. Production of Jerusalem artichoke on saline land is strategically important for using saline land resources. The interaction between plant hormones and salinity stress in governing Jerusalem artichoke (Helianthus tuberosus) growth is unclear. Jerusalem artichoke (variety Nanyu-1) was grown under variable salinity stress in the field, and a role of endogenous hormones [zeatin (ZT), auxins (IAA), gibberellins (GA3) and abscisic acid (ABA)] in regulating sugar and dry matter accumulation in tubers was characterized. Under mild salt stress (≤2.2gNaClkg(-1) soil), Nanyu-1 grew well with no significant alteration of dry matter distribution to stems and tubers. In contrast, under moderate salt stress (2.7gNaClkg(-1) soil), the distribution to stem decreased and to tubers decreased significantly. Mild salt stress induced sugar accumulation in tubers at the beginning of the tuber-expansion period, but significantly inhibited (i) transfer of non-reducing sugars to tubers, and (ii) polymerization and accumulation of fructan during the tuber-expansion stage. Under different salinity stress, before the stolon growth, the ratio of IAA/ABA in leaves increased significantly and that of GA3/ABA increased slightly; during tuber development, these ratios continued to decrease and reached the minimum late in the tuber-expansion period. While, salt stress inhibited (i) underground dry matter accumulation, (ii) tuber dry matter accumulation efficiency, (iii) transport of non-reducing sugars to tubers, and (iv) fructan accumulation efficiency during the tuber-expansion period; these effects were accompanied by significantly decreased tuber yield with an increase in salinity. With soil salinity increasing, the synthesis of IAA and GA3 was inhibited in leaves and tubers, while ABA synthesis was stimulated. In brief, tuber yield would significantly decreased with the increase of salinity.

  20. Sources of information influencing the state-of-the-science gap in hormone replacement therapy usage

    PubMed Central

    Wu, Xianwei

    2017-01-01

    Objective Medical reviews and research comprise a key information source for news media stories on medical therapies and innovations as well as for physicians in updating their practice. The present study examined medical review journal articles, physician surveys and news media coverage of hormone replacement therapy (HT) to assess the relationship between the three information sources and whether/if they contributed to a state-of-the-science gap (a condition when the evaluation of a medical condition or therapy ascertained by the highest standards of investigation is incongruent with the science-in-practice such as physician recommendations and patient actions). Methods We content-analyzed 177 randomly sampled HT medical reviews between 2002 and 2014, and HT news valence in three major TV networks, newspapers and magazines/internet sites in 2002–2003, 2008–2009 and 2012–14. The focus in both analyses was whether HT benefits outweighed risks, risks outweighed benefits or both risks and benefits were presented. We also qualitatively content-analyzed all 19 surveys of US physicians’ HT recommendations from 2002 to 2009, and 2012 to 2014. Results Medical reviews yielded a mixed picture about HT (40.1% benefits, 26.0% risks, and 33.9% both benefits and risks). While a majority of physician surveys were pro-HT 10/19), eight showed varied attitudes and one was negative. Newspaper and television coverage reflected a pro and con balance while magazine stories were more positive in the later reporting period. Conclusion Medical journal review articles, physicians, and media reports all provide varying view points towards hormone therapy use thus leading to limited knowledge about the actual risks and benefits of HT among peri- and menopausal women and a state-of-the-science gap. PMID:28158240

  1. Hormone influence on the spatial regulation of IRT1 expression in iron-deficient Arabidopsis thaliana roots.

    PubMed

    Blum, Ailisa; Brumbarova, Tzvetina; Bauer, Petra; Ivanov, Rumen

    2014-04-10

    The IRON-REGULATED TRANSPORTER1 (IRT1) is the principal importer of soil iron in Arabidopsis thaliana. It has a complex intracellular trafficking behavior, including continuous cycling between plasma membrane and endosomes. SORTING NEXIN1 is required for the recycling of endosome-localized IRT1. In its absence, IRT1 is mistargeted for degradation, resulting in reduced plant iron-uptake efficiency. Consequently, IRT1 promoter activity gets limited to a specific portion of the root. We tested the influence of two hormones known to positively affect iron uptake on IRT1 spatial regulation. We found that ethylene treatment in wild-type background mimics the effects of the SNX-loss-of-function situation. Conversely, auxin splits the IRT1 expression zone and forces it toward the two extremities of the root. This shows that IRT1 expression along the root is modulated by ethylene-auxin interplay.

  2. Juvenile rheumatoid arthritis

    MedlinePlus

    ... joints. This form of JIA may turn into rheumatoid arthritis. It may involve five or more large and ... no known prevention for JIA. Alternative Names Juvenile rheumatoid arthritis (JRA); Juvenile chronic polyarthritis; Still disease; Juvenile spondyloarthritis ...

  3. Juvenile Idiopathic Arthritis

    MedlinePlus

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Juvenile Idiopathic Arthritis (JIA) KidsHealth > For Teens > Juvenile Idiopathic ... can affect people under age 17. What Is Juvenile Idiopathic Arthritis? Arthritis doesn't affect young people ...

  4. Influence of dietary calcium, phosphorus, zinc and sodium phytate level on cataract incidence, growth and histopathology in juvenile chinook salmon (Oncorhynchus tshawytscha).

    PubMed

    Richardson, N L; Higgs, D A; Beames, R M; McBride, J R

    1985-05-01

    To determine the influence of wide variations in dietary levels of calcium, zinc and phytic acid (as sodium phytate) on growth and cataract incidence, juvenile chinook salmon held at 10-11 degrees C were fed daily to satiation for 105 d one of nine purified diets containing one of three levels (grams/kilogram) of calcium (averaged 4.8, 17.7, 50.2), zinc (averaged 0.05, 0.15, 0.39) and phytic acid (1.62, 6.46, 25.8). Diets were formulated to have a calcium-phosphorus ratio of close to unity when considering phosphorus sources other than sodium phytate. High dietary phytic acid concentration (25.8 g/kg) depressed chinook salmon growth, food and protein conversion [protein efficiency ratio (PER)] and thyroid function, increased mortality, promoted cataract formation (zinc at 0.05 g/kg) and induced anomalies in pyloric cecal structure. Calcium at 51 g/kg (or phosphorus) exacerbated the effects of high dietary phytate and low dietary zinc on cataract incidence. Moreover, high dietary levels of calcium (48-51 g/kg) coupled with phosphorus significantly impaired the growth and appetite of low phytic acid (1.62 g/kg) groups and led to nephrocalcinosis in low and high phytic acid groups. Plasma zinc levels were directly related to dietary zinc concentration and inversely related to dietary phytic acid level. Calcium (51 g/kg) and/or phosphorus reduced zinc bioavailability when the diet concurrently contained 0.05 g zinc and 25.8 g of phytic acid per kilogram. It is concluded that zinc is essential for normal eye development in juvenile chinook salmon. Further, zinc deficiency could not be induced in chinook salmon fed diets with high ratios of calcium (or phosphorus) to zinc alone. This required the simultaneous presence of a strong mineral (zinc)-binding agent.

  5. Water stress, CO2 and photoperiod influence hormone levels in wheat

    NASA Technical Reports Server (NTRS)

    Nan, Rubin; Carman, John G.; Salisbury, Frank B.; Campbell, W. F. (Principal Investigator)

    2002-01-01

    'Super Dwarf' wheat (Triticum aestivum L.) plants have been grown from seed to maturity in the Mir space station where they were periodically exposed, because of microgravity and other constraints, to water deficit, waterlogging, high CO2 levels, and low light intensities. The plants produced many tillers, but none of them produced viable seed. Studies have been initiated to determine why the plants responded in these ways. In the present study, effects of the listed stresses on abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl adenosine ([9R]iP) levels in roots and leaves of plants grown under otherwise near optimal conditions on earth were measured. Hormones were extracted, purified by HPLC, and quantified by noncompetitive indirect ELISA. In response to water deficit, ABA levels increased in roots and leaves, IAA levels decreased in roots and leaves, and [9R]iP levels increased in leaves but decreased in roots. In response to waterlogging, ABA, IAA and [9R]iP levels briefly increased in roots and leaves and then decreased. When portions of the root system were exposed to waterlogging and/or water deficit, ABA levels in leaves increased while [9R]iP and IAA levels decreased. These responses were correlated with the percentage of the root system stressed. At a low photosynthetic photon flux (100 micromoles m-2 s-1), plants grown in continuous light had higher leaf ABA levels than plants grown using an 18 or 21 h photoperiod.

  6. Uptake of Pharmaceuticals Influences Plant Development and Affects Nutrient and Hormone Homeostases.

    PubMed

    Carter, Laura J; Williams, Mike; Böttcher, Christine; Kookana, Rai S

    2015-10-20

    The detection of a range of active pharmaceutical ingredients (APIs) in the soil environment has led to a number of publications demonstrating uptake by crops, however very few studies have explored the potential for impacts on plant development as a result of API uptake. This study investigated the effect of carbamazepine and verapamil (0.005-10 mg/kg) on a range of plant responses in zucchini (Cucurbita pepo). Uptake increased in a dose-dependent manner, with maximum leaf concentrations of 821.9 and 2.2 mg/kg for carbamazepine and verapamil, respectively. Increased carbamazepine uptake by zucchini resulted in a decrease in above (<60%) and below (<30%) ground biomass compared to the controls (p < 0.05). At soil concentrations >4 mg/kg the mature leaves suffered from burnt edges and white spots as well as a reduction in photosynthetic pigments but no such effects were seen for verapamil. For both APIs, further investigations revealed significant differences in the concentrations of selected plant hormones (auxins, cytokinins, abscisic acid and jasmonates), and in the nutrient composition of the leaves in comparison to the controls (p < 0.05). This is some of the first research to demonstrate that the exposure of plants to APIs is likely to cause impacts on plant development with unknown implications.

  7. Oral hormone replacement therapy: factors that influence the estradiol concentrations achieved in a multiracial study population.

    PubMed

    Gavaler, Judith S

    2002-02-01

    The assumption that estradiol (E2) concentrations are reliably increased to therapeutic levels in postmenopausal women receiving hormone replacement therapy (HRT) has not been explicitly tested. Nor have factors that may modulate the E2 levels achieved been evaluated. The author examined E2 concentrations in a multiracial study population of 309 postmenopausal women treated with oral HRT and observed that 51.1% had achieved estradiol levels of at least 45 pg/ml (achievers). The odds of being an achiever were significantly elevated among non-Caucasian women by a HRT dose greater than 0.625 mg, current moderate drinking, and increasing duration of HRT use. The odds were significantly decreased by having a high school education or less and increasing time since last HRT dose. White postmenopausal women had significantly reduced odds of being an achiever, and both a dose of less than 0.625 mg and a dose equal to 0.625 mg significantly reduced the odds of being an achiever. Increasing body mass index and menopause duration were both associated with lower odds. This report demonstrates not only that women treated with HRTdo not all achieve therapeutic levels of estradiol but also that factors can be identified that modulate the E2 concentration achieved in response to HRT administration.

  8. Water stress, CO2 and photoperiod influence hormone levels in wheat.

    PubMed

    Nan, Rubin; Carman, John G; Salisbury, Frank B

    2002-03-01

    'Super Dwarf' wheat (Triticum aestivum L.) plants have been grown from seed to maturity in the Mir space station where they were periodically exposed, because of microgravity and other constraints, to water deficit, waterlogging, high CO2 levels, and low light intensities. The plants produced many tillers, but none of them produced viable seed. Studies have been initiated to determine why the plants responded in these ways. In the present study, effects of the listed stresses on abscisic acid (ABA), indole-3-acetic acid (IAA) and isopentenyl adenosine ([9R]iP) levels in roots and leaves of plants grown under otherwise near optimal conditions on earth were measured. Hormones were extracted, purified by HPLC, and quantified by noncompetitive indirect ELISA. In response to water deficit, ABA levels increased in roots and leaves, IAA levels decreased in roots and leaves, and [9R]iP levels increased in leaves but decreased in roots. In response to waterlogging, ABA, IAA and [9R]iP levels briefly increased in roots and leaves and then decreased. When portions of the root system were exposed to waterlogging and/or water deficit, ABA levels in leaves increased while [9R]iP and IAA levels decreased. These responses were correlated with the percentage of the root system stressed. At a low photosynthetic photon flux (100 micromoles m-2 s-1), plants grown in continuous light had higher leaf ABA levels than plants grown using an 18 or 21 h photoperiod.

  9. The association between anti-Müllerian hormone and IVF pregnancy outcomes is influenced by age.

    PubMed

    Wang, Jeff G; Douglas, Nataki C; Nakhuda, Gary S; Choi, Janet M; Park, Susanna J; Thornton, Melvin H; Guarnaccia, Michael M; Sauer, Mark V

    2010-12-01

    The conflicting results from studies on the predictive capabilities of serum anti-Müllerian hormone (AMH) for IVF pregnancy outcomes may be attributed to small sample sizes and disparities in the age of the study populations. The relationship between AMH and IVF pregnancy outcomes was clarified with retrospective cross-tabulation analyses (n=1558) stratified by age to control for its confounding effects. Serum AMH concentrations were divided into tertiles (≤ 0.29, 0.30-1.20, ≥ 1.21 ng/ml) and ages into four groups (<34, 34-37, 38-41, ≥ 42 years). For women <34, having serum AMH in the lowest tertile did not reduce the chance of IVF pregnancy/live birth compared with those with higher AMH concentrations. For women 34-41, a significant positive relationship existed between serum AMH and pregnancy rates. For women ≥ 42, serum AMH concentrations ≤ 0.29 ng/ml were associated with a 3% chance of pregnancy, and women with AMH ≥ 1.21 ng/ml had the same pregnancy rate as women with concentrations 0.30-1.20 ng/ml. In conclusion, AMH has limited predictive value for IVF outcomes in the two extremes of female reproductive age; however, for women between 34 and 41, higher serum AMH concentrations are associated with significantly greater chances of pregnancy (P<0.01).

  10. Adipocyte-derived hormones in heroin addicts: the influence of methadone maintenance treatment.

    PubMed

    Housová, J; Wilczek, H; Haluzík, M M; Kremen, J; Krízová, J; Haluzík, M

    2005-01-01

    Heroin addiction markedly affects the nutritional and metabolic status and frequently leads to malnutrition. The aim of our study was to compare circulating concentration of adipose tissue-derived hormones leptin, adiponectin and resistin in 12 patients with heroin addiction before and after one-year methadone maintenance treatment with the group of 20 age- and body mass index-matched healthy subjects. Basal serum leptin and adiponectin levels in heroin addicts were significantly decreased (3.4+/-0.4 vs. 4.5+/-0.6 ng/ml and 18.9+/-3.3 vs. 33.9+/-3.1 ng/microl, respectively; p 0.05) while serum resistin concentrations were increased compared to healthy subjects (10.1+/-1.2 vs. 4.6+/-0.3 ng/ml; p 0.05). Moreover, positive correlation of serum leptin levels with body mass index was lost in the addicts in contrast to control group. One year of methadone maintenance treatment normalized serum leptin, but not serum adiponectin and resistin concentrations. In conclusion, circulating concentrations of leptin, adiponectin and resistin are markedly altered in patients with chronic heroin addiction. These alterations appear to be relatively independent of nutritional status and insulin sensitivity.

  11. Influence of Parathyroid Hormone-Loaded PLGA Nanoparticles in Porous Scaffolds for Bone Regeneration

    PubMed Central

    Gentile, Piergiorgio; Nandagiri, Vijay Kumar; Pabari, Ritesh; Daly, Jacqueline; Tonda-Turo, Chiara; Ciardelli, Gianluca; Ramtoola, Zebunnissa

    2015-01-01

    Biodegradable poly(lactide-co-glycolide) (PLGA) nanoparticles, containing human parathyroid hormone (PTH (1–34)), prepared by a modified double emulsion-solvent diffusion-evaporation method, were incorporated in porous freeze-dried chitosan-gelatin (CH-G) scaffolds. The PTH-loaded nanoparticles (NPTH) were characterised in terms of morphology, size, protein loading, release kinetics and in vitro assessment of biological activity of released PTH and cytocompatibility studies against clonal human osteoblast (hFOB) cells. Structural integrity of incorporated and released PTH from nanoparticles was found to be intact by using Tris-tricine SDS-PAGE. In vitro PTH release kinetics from PLGA nanoparticles were characterised by a burst release followed by a slow release phase for 3–4 weeks. The released PTH was biologically active as evidenced by the stimulated release of cyclic AMP from hFOB cells as well as increased mineralisation studies. Both in vitro and cell studies demonstrated that the PTH bioactivity was maintained during the fabrication of PLGA nanoparticles and upon release. Finally, a content of 33.3% w/w NPTHs was incorporated in CH-G scaffolds, showing an intermittent release during the first 10 days and, followed by a controlled release over 28 days of observation time. The increased expression of Alkaline Phosphatase levels on hFOB cells further confirmed the activity of intermittently released PTH from scaffolds. PMID:26343649

  12. Influence of modified transdermal hormone replacement therapy on the concentrations of hormones, growth factors, and bone mineral density in women with osteopenia.

    PubMed

    Stanosz, Staniaław; Zochowska, Ewa; Safranow, Krzysztof; Sieja, Krzysztof; Stanosz, Małgorzta

    2009-01-01

    The metabolic and therapeutic action of estrogens depends on their type, dosage, form, route of administration, and treatment-free interval during the therapeutic cycle. Hormone therapy is generally subclassified into 2 forms that differ in the type of hormones. In hormonal replacement therapy (HRT), estrogens and progesterone components do not differ in chemical structure and molecular mass from those naturally produced by the female organism. In hormonal supplementary therapy (HST), the estrogen and progestagen components do differ from the natural hormones in structure and mass. The aim of the study was to compare 2 kinds of hormonal therapy in early postmenopausal women with osteopenia. These forms of therapy are modified transdermal HRT and orally given HST. The objective of this study was the estimation of sex hormone, insulin-like growth factor I (IGF-I), prolactin (PRL), osteocalcin, and procollagen concentration in serum as well as the degree of mineralization of the lumbar spine in women in the early postmenopausal period with osteopenia under different kinds of hormonal therapy. The study was conducted in 75 women with an average age of 52.4 +/- 3.5 years and with primary osteopenia, in the early postmenopausal period, who were randomly assigned to 3 groups depending on the form and route of administration of therapy: Group I (n = 25, control) was receiving placebo in the form of patches. Group II (n = 25) was treated with modified transdermal HRT. This group obtained micronized 17beta-estradiol at increasing-decreasing doses and progesterone in the second phase of the therapeutic cycle. Group III (n = 25) was receiving orally given HST and obtained Cyclo-Menorette (Wyeth, Munster, Germany). The therapeutic cycle in each group lasted 21 days, followed by a 7-day medication-free interval. Estradiol concentration in serum was increased 5-fold and estrone (E(1)) was increased about 11-fold in the group of women receiving orally given HST (P < .0001

  13. Size and age distributions of Juvenile Connecticut River American shad above Hadley Falls: Influence on outmigration representation and timing

    USGS Publications Warehouse

    O'Donnell, M. J.; Letcher, B.H.

    2008-01-01

    Age- and size-based habitat use and movement patterns of young-of-year American shad in rivers are not well understood. Adult females reach their natal rivers at different times and ascend the river at different rates, which may lead to variation of hatch dates at a single location. Also, shad are serial spawners, so eggs of the same female may be released at different distances from the river mouth. It has long been hypothesized that juvenile shad emigration is a function of size or age, and not necessarily keyed only to a decrease in water temperature during the fall. We seined three sites in the Connecticut River biweekly to collect pre-migrant shad during river residence (spring to fall). During emigration, samples were also collected weekly at two hydroelectric facilities. Otoliths were removed from ???20% of the fish to obtain age and growth rate information. We found increases in length and age over time until late in the season, after which such increases were mostly insigniftlant. Cohorts collected early in the year as pre-migrants were never sampled as migrants later in the year at the hydroelectric projects. Cohorts collected late in the year as migrants were never collected earlier in the year as pre-migrants. Only during a narrow window of time were fish collected as both pre-migrants and migrants. Fish that were hatched later in the season exhibited higher growth rates than fish that were hatched earlier in the season. Copyright ?? 2008 John Wiley & Sons, Ltd.

  14. Race, Legal Representation, and Juvenile Justice: Issues and Concerns

    ERIC Educational Resources Information Center

    Guevara, Lori; Spohn, Cassia; Herz, Denise

    2004-01-01

    The objective of this study was to examine the influence of type of counsel across race on juvenile court outcomes. Using data from a sample of juvenile court referrals from two midwestern juvenile courts, this study examined the interaction of race and type of counsel on disposition outcome. The results indicated that youth without an attorney…

  15. Fighting Juvenile Gun Violence. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Sheppard, David; Grant, Heath; Rowe, Wendy; Jacobs, Nancy

    This bulletin describes the Office of Juvenile Justice and Delinquency Prevention's efforts to fight juvenile gun violence. The Office awarded four community demonstration grants to implement "Partnerships To Reduce Juvenile Gun Violence." Partnership goals include increasing the effectiveness of existing strategies by enhancing and…

  16. Sampling and storage conditions influencing the measurement of parathyroid hormone in blood samples: a systematic review.

    PubMed

    Hanon, Elodie A; Sturgeon, Catharine M; Lamb, Edmund J

    2013-10-01

    Parathyroid hormone (PTH) is relatively unstable: optimisation of pre-analytical conditions, including specimen type, sampling time and storage conditions, is essential. We have undertaken a systematic review of these pre-analytical conditions. An electronic search of the PubMed, Embase, Cochrane, Centre for Research and Dissemination and Bandolier databases was undertaken. Of 5511 papers identified, 96 underwent full text review, of which 83 were finally included. At room temperature PTH was stable in ethylenediaminetetraacetic acid (EDTA) preserved whole blood for at least 24 h and in EDTA plasma for at least 48 h after venepuncture. Losses were observed in clotted blood samples after 3 h and in serum after 2 h. At 4°C PTH was more stable in EDTA plasma (at least 72 h) than serum (at least 24 h). Central venous PTH concentrations were higher than peripheral venous concentrations. In the northern hemisphere, PTH concentrations were higher in winter than summer. PTH has a circadian rhythm characterised by a nocturnal acrophase and mid-morning nadir. Data related to frozen storage of PTH (-20°C and -80°C) were limited and contradictory. We recommend that blood samples for PTH measurement should be taken into tubes containing EDTA, ideally between 10:00 and 16:00, and plasma separated within 24 h of venepuncture. Plasma samples should be stored at 4°C and analysed within 72 h of venepuncture. Particular regard must be paid to the venepuncture site when interpreting PTH concentration. Further research is required to clarify the suitability of freezing samples prior to PTH measurement.

  17. Influence of androgens on plasma concentrations of growth hormone in growing castrated and intact chickens.

    PubMed

    Fennell, M J; Johnson, A L; Scanes, C G

    1990-03-01

    Castrated chicks implanted with testosterone or 5 alpha-dihydrotestosterone (5 alpha-DHT) had circulating concentrations of the respective androgen similar to or less than in sham-operated chicks. In castrated chicks, 5 alpha-DHT or 19-nortestosterone (19-NorT) inhibited growth as indicated by body weight, while testosterone and 5 beta-dihydrotestosterone (5 beta-DHT) were without effect. In intact male or female chicks, growth was inhibited by either testosterone or 5 alpha-DHT but was unaffected by 5 beta-DHT or estradiol-17 beta. Plasma concentrations of luteinizing hormone (LH) were reduced in castrated chicks receiving implants of either testosterone or 19-NorT. Only the highest dose of 5 alpha-DHT depressed the circulating concentration of LH; lower doses of 5 alpha-DHT being without effect. During the first 6 weeks of growth, plasma concentrations of GH were unaffected by most steroid treatments (5 alpha-DHT, 5 beta-DHT, low doses of testosterone, estradiol-17 beta) in castrated or in intact male or in female chicks. Similarly, 19-NorT did not affect plasma concentrations of GH in castrated chicks. The high dose of testosterone, however, depressed plasma concentrations of GH in castrated chicks between 2 and 6 weeks of age. Between 8 and 12 weeks of age, all steroids tested, except 5 alpha-DHT, were without effect on plasma concentrations of GH. Plasma concentrations of GH were increased in 5 alpha-DHT-treated chickens. This effect was observed irrespective of dose of 5 alpha-DHT or whether the androgen was administered to castrated or to intact male or to female chicks.

  18. Influence of structured counseling on women’s selection of hormonal contraception in Israel: results of the CHOICE study

    PubMed Central

    Yeshaya, Arie; Ber, Amos; Seidman, Daniel S; Oddens, Bjorn J

    2014-01-01

    Background The multinational CHOICE (Contraceptive Health Research Of Informed Choice Experience) study evaluated the effects of structured counseling on women’s contraceptive decisions, their reasons for making those decisions, and their perceptions of combined hormonal contraceptive (CHC) methods in eleven countries. The aim of this paper to present data from the 1,802 women participating in Israel’s CHOICE program. Methods Women (aged 17–40 years) who consulted their health care providers about contraception and who would consider a CHC method qualified to participate. After indicating their intended CHC method, the women received counseling about the daily pill, weekly patch, and monthly vaginal ring. After counseling, the women completed a questionnaire about their contraceptive decisions. Results Before counseling, 67%, 6%, and 5% of women (mean age 27 years) intended to use the pill, patch, or ring, respectively. Counseling significantly influenced the women’s CHC choice, with 56%, 12%, and 23% of women selecting the pill, patch, or ring (P<0.0001 for all contraceptive methods versus before counseling). Logistic regression analysis suggested that age significantly increased the probability of switching from the pill to the ring. Conclusion Although the pill was the most popular choice overall, counseling appeared to influence Israeli women’s contraceptive decisions, with significantly more women selecting the patch. More than four times as many women selected the ring after counseling than before counseling. PMID:25187739

  19. Gender Development in 46,XY DSD: Influences of Chromosomes, Hormones, and Interactions with Parents and Healthcare Professionals

    PubMed Central

    Wisniewski, Amy B.

    2012-01-01

    Variables that impact gender development in humans are difficult to evaluate. This difficulty exists because it is not usually possible to tease apart biological influences on gender from social variables. People with disorders of sex development, or DSD, provide important opportunities to study gender within individuals for whom biologic components of sex can be discordant with social components of gender. While most studies of gender development in people with 46,XY DSD have historically emphasized the importance of genes and hormones on gender identity and gender role, more recent evidence for a significant role for socialization exists and is considered here. For example, the influence of parents' perceptions of, and reactions to, DSD are considered. Additionally, the impact of treatments for DSD such as receiving gonadal surgeries or genitoplasty to reduce genital ambiguity on the psychological development of people with 46,XY DSD is presented. Finally, the role of multi-disciplinary care including access to peer support for advancing medical, surgical and psychosexual outcomes of children and adults with 46,XY DSD, regardless of sex of rearing, is discussed. PMID:24278745

  20. Gender Development in 46,XY DSD: Influences of Chromosomes, Hormones, and Interactions with Parents and Healthcare Professionals.

    PubMed

    Wisniewski, Amy B

    2012-01-01

    Variables that impact gender development in humans are difficult to evaluate. This difficulty exists because it is not usually possible to tease apart biological influences on gender from social variables. People with disorders of sex development, or DSD, provide important opportunities to study gender within individuals for whom biologic components of sex can be discordant with social components of gender. While most studies of gender development in people with 46,XY DSD have historically emphasized the importance of genes and hormones on gender identity and gender role, more recent evidence for a significant role for socialization exists and is considered here. For example, the influence of parents' perceptions of, and reactions to, DSD are considered. Additionally, the impact of treatments for DSD such as receiving gonadal surgeries or genitoplasty to reduce genital ambiguity on the psychological development of people with 46,XY DSD is presented. Finally, the role of multi-disciplinary care including access to peer support for advancing medical, surgical and psychosexual outcomes of children and adults with 46,XY DSD, regardless of sex of rearing, is discussed.

  1. Giving birth to a new brain: hormone exposures of pregnancy influence human memory.

    PubMed

    Glynn, Laura M

    2010-09-01

    Mammalian pregnancy produces alterations in maternal physiology that are necessary for maintaining gestation, fetal development and parturition. These changes also may prepare the maternal brain for the unique demands of motherhood. Parous rodents exhibit long-term changes in neurological structure and function and human work suggests that other landmark events in the reproductive cycle, such as menarche and menopause, influence cognition. However, the influence of pregnancy on the human brain remains to be elucidated. This study indicates that verbal recall memory (but not recognition or working memory) diminishes during human pregnancy and that these decrements persist after parturition. Further, prenatal glucocorticoids and estrogen are associated with these alterations. To meet the challenges of motherhood, the female brain may be remodeled, a process that appears to be initiated prenatally. However, it is not often that adaptation is achieved without an associated cost. For the human, in the case of the new maternal brain, diminished memory performance may reflect such a cost.

  2. Influence of processing and cooking of carrots in mixed meals on satiety, glucose and hormonal response.

    PubMed

    Gustafsson, K; Asp, N G; Hagander, B; Nyman, M; Schweizer, T

    1995-02-01

    The influence of processing and cooking on the metabolic response to carrots in mixed meals was explored in two consecutive harvest years. The contribution of dietary fibre (4.4 g 1989 and 6.6 g 1990) from carrots was chosen to be different in order to compare effects with varying doses. The meals, composed of carrots, creamed potatoes, meat balls, lingonberry jam, white bread and light beer, were served in the morning after an overnight fast to 10 healthy male volunteers. Carrots were investigated raw, processed (blanched and frozen) and variously cooked (thawed, boiled and microwaved). The amount of dietary fibre from the vegetable, and the content of energy, digestible carbohydrates, fat and protein were similar in the meals compared. Significantly lower glucose, insulin and C-peptide responses and higher satiety scores were elicited with raw carrots than with microwaved ones, harvest year 1989. The next year, with a higher dietary fibre intake from carrots, there were significant effects of processing only on the glucose response. Plasma beta-carotene levels tended to be higher postprandially with raw carrots than with microwaved ones. Hence, ordinary processing and cooking of vegetables can affect the metabolic response to a mixed meal. However, the influence seems to be varying and of minor importance in ordinary meals. Increasing vegetable portions entailing a higher soluble fibre content and a higher viscosity could further reduce the influence of processing.

  3. Juvenile Justice & Youth Violence.

    ERIC Educational Resources Information Center

    Howell, James C.

    Youth violence and the juvenile justice system in the United States are explored. Part 1 takes stock of the situation. The first chapter discusses the origins and evaluation of the juvenile justice system, and the second considers the contributions of the Federal Juvenile Justice and Delinquency Prevention Act to the existing juvenile justice…

  4. INFLUENCE OF LARVAL EXPOSURE TO SALINITY AND CADMIUM STRESS ON JUVENILE PERFORMANCE OF TWO MARINE INVERTEBRATES, CAPITELLA SP I AND CREPIDULA FORNICATA

    EPA Science Inventory

    Delayed metamorphosis and short-term food limitation reduce juvenile or adult fitness in a number of marine invertebrate species. In this study, we tested the ability of pollutant and salinity stress to bring about similar effects on juvenile or adult performance. Larvae of the p...

  5. HORMONAL PROCESSES IN DECAPOD CRUSTACEAN LARVAE AS BIOMARKERS OF ENDOCRINE DISRUPTING CHEMICALS IN THE MARINE ENVIRONMENT

    EPA Science Inventory

    Knowledge of endocrine control of the complex larval developmental processes in insects (metamorphosis) has led to the introduction of insect hormones and their analogues as insecticides known as insect growth regulators (IGRs) with the largest group being juvenile hormone analog...

  6. Influence of hormonal status on enkephalin-degrading aminopeptidase activity in the HPA axis of female mice.

    PubMed

    García-López, M J; Martínez-Martos, J M; Mayas, M D; Carrera, M P; Ramírez-Expósito, M J

    2005-04-01

    Opioids are involved in the regulation of hypothalamus-pituitary-adrenal (HPA) axis activity under physiological conditions. In the present work, we analyzed the influence of ovariectomy and estradiol (E), progesterone (P) or estradiol plus progesterone (E+P) replacement on soluble (S) and membrane-bound (MB) enkephalin-degrading aminopeptidase activity (EDA) in the HPA axis. Female mice (Balb/C) were distributed in 15 groups of 10 animals each: sham-operated controls (C), ovariectomized controls (OV-C), and ovariectomized mice treated with increasing doses of E (10, 20 or 40 mg/kg), P (100, 200 or 400 mg/kg) or E+P (10+100, 20+200 or 40+400 mg/kg). In hypothalamus, ovariectomy increased both S and MB EDA activities, whereas E replacement returned them to control levels, although MB EDA activity increased again after the replacement with 40 mg/kg E. P replacement increased S EDA activity, but returned MB EDA activity to control levels. The replacement of E+P returned both S and MB EDA activities to control levels, although MB EDA activity was lower than control values after the replacement with 10+100 mg/kg E+P. In pituitary, neither ovariectomy nor the replacement of E or E+P changed S EDA, although the highest concentrations of P increased S EDA activity. However, ovariectomy increased MB EDA and E replacement returned the activity to control or below control levels, depending on the concentration used. However, P administration returned the activity to control or below control levels depending on the concentration used, although 200 mg/kg P had no effects on MB EDA. E+P replacement returned pituitary MB EDA activity to control levels. In adrenal glands, ovariectomy did change either S or MB EDA. However, E, P or E+P replacement decreased S EDA activity in different degrees, depending of the dose administrated. No changes were detected in MB EDA after hormone replacement. These results indicate that female steroid hormones influence EDA activity at different

  7. Hormonal influence on glycosaminoglycan synthesis in uterine connective tissue of term pregnant women.

    PubMed

    Wiqvist, I; Linde, A

    1987-04-01

    Adaptation of the uterus to the growing fetus necessitates remodelling of the uterine connective tissue. Proteoglycans, being a main constituent of the extracellular matrix, influence the physical properties of the tissue and play an important regulatory role for a number of functional events. The synthesis of glycosaminoglycans (GAGs), the carboxyhydrate side chains of proteoglycans, in tissue from the lower uterine segment of term pregnant women was investigated in vitro by measurement of 35SO4 and [14C]glucosamine incorporation. Prostaglandin E2 and oestradiol-17 beta significantly increased the synthesis of sulphated GAGs but decreased the incorporation of [14C]glucosamine, while relaxin, prostaglandin F2 alpha and oxytocin had no significant effect. To further explore the influence of prostaglandin E2, tissue specimens were incubated with [14C]glucosamine and GAGs separated into three fractions on cetylpyridinium chloride cellulose micro columns. Prostaglandin E2 was found to significantly reduce the synthesis of components recovered in the glycoprotein and hyaluronate fractions, whereas synthesis of components in the sulphated GAG fraction was increased. The results indicate that prostaglandin E2 and oestradiol-17 beta have differential effects on different GAGs whereas relaxin, oxytocin and prostaglandin F2 alpha have no effect.

  8. Sensitive skin and the influence of female hormone fluctuations: results from a cross-sectional digital survey in the Dutch population.

    PubMed

    Falcone, Denise; Richters, Renée J H; Uzunbajakava, Natallia E; Van Erp, Piet E J; Van De Kerkhof, Peter C M

    2017-02-01

    Sensitive skin is a widespread condition, which is most frequently reported by women. Changing hormone levels during the menstrual cycle and menopause have been suggested among the stimuli triggering sensitive skin. To investigate the perceived influence of fluctuating hormone levels on self-assessed sensitive skin, including symptoms and stimuli linked to skin sensitivity, as well as potential changes in facial and body skin and sensitive body parts, depending on hormonal status. A digital questionnaire was distributed to a population of women aged 20-65 years old. A total of 278 women were included in the analysis. About 42% premenopausal women declared a perception of (increased) skin sensitivity just before and during the menstrual cycle, while this was reported by almost 32% of peri- and postmenopausal women following the menopause. The majority of reported symptoms included the presence of bumps/pimples, dryness, itching, and redness, and the majority of reported stimuli were shaving, weather, toiletries, and emotions. No differences emerged regarding characteristics of facial and body skin across different hormonal status. Significant differences in sensitivity of body parts emerged for the face and feet, reported by a larger percentage of premenopausal women and peri- and postmenopausal women, respectively. The prevalence of the perceived effects of fluctuating hormone levels on self-assessed sensitive skin in women is high. These effects should be taken into consideration in skin testing and dermatological practice, and support the need for selecting personal care routine or treatment during the menstrual cycle and menopause.

  9. Plasma steroid hormone levels in female flounder Platichthys flesus and the influence of fluctuating hydrostatic pressure.

    PubMed

    Damasceno-Oliveira, A; Fernández-Durán, B; Gonçalves, J; Couto, E; Canário, A V M; Coimbra, J

    2012-11-01

    The reproductive cycle in teleosts is timed to guarantee that eggs hatch in the right place at the right time, with environmental factors playing important roles in entraining and controlling the entire process. The effects of some environmental factors, like temperature and photoperiod, are now well understood. There are only a few studies regarding the effects of hydrostatic pressure (HP) on the reproductive cycle, in spite of its importance as a ubiquitous factor in all biological environments and affecting all living organisms. Hydrostatic pressure is of particular importance in fish because they can also experience rapid and cyclic changes in HP due to vertical movements in the water column. The aim of the present research was to investigate the effects of vertical migrations on the reproductive steroids of maturing female flounder. After a 14 day exposure to cyclic hydrostatic pressure (with a period of 12.4h and with a maximum peak of 800 kPa of absolute hydrostatic pressure), fish showed significantly lower plasmatic concentrations of "5β,3α" steroids, metabolites of the putative maturation-inducing steroid in flounder (17α,20β-dihydroxy-4-pregnen-3-one). Results indicate that environmentally realistic cyclic changes of hydrostatic pressure can influence the metabolism of reproductive steroids. This suggests a physiological role of tidally-associated vertical migrations, affecting oocyte maturation and retarding the reproductive cycle in this species until the spawning ground is attained.

  10. Corticotropin-releasing hormone receptor type 1 (CRHR1) genetic variation and stress interact to influence reward learning.

    PubMed

    Bogdan, Ryan; Santesso, Diane L; Fagerness, Jesen; Perlis, Roy H; Pizzagalli, Diego A

    2011-09-14

    Stress is a general risk factor for psychopathology, but the mechanisms underlying this relationship remain largely unknown. Animal studies and limited human research suggest that stress can induce anhedonic behavior. Moreover, emerging data indicate that genetic variation within the corticotropin-releasing hormone type 1 receptor gene (CRHR1) at rs12938031 may promote psychopathology, particularly in the context of stress. Using an intermediate phenotypic neurogenetics approach, we assessed how stress and CRHR1 genetic variation (rs12938031) influence reward learning, an important component of anhedonia. Psychiatrically healthy female participants (n = 75) completed a probabilistic reward learning task during stress and no-stress conditions while 128-channel event-related potentials were recorded. Fifty-six participants were also genotyped across CRHR1. Response bias, an individual's ability to modulate behavior as a function of reward, was the primary behavioral variable of interest. The feedback-related positivity (FRP) in response to reward feedback was used as a neural index of reward learning. Relative to the no-stress condition, acute stress was associated with blunted response bias as well as a smaller and delayed FRP (indicative of disrupted reward learning) and reduced anterior cingulate and orbitofrontal cortex activation to reward. Critically, rs12938031 interacted with stress to influence reward learning: both behaviorally and neurally, A homozygotes showed stress-induced reward learning abnormalities. These findings indicate that acute, uncontrollable stressors reduce participants' ability to modulate behavior as a function of reward, and that such effects are modulated by CRHR1 genotype. Homozygosity for the A allele at rs12938031 may increase risk for psychopathology via stress-induced reward learning deficits.

  11. Influence of bone and soft-tissue operations on serum concentrations of growth hormone, somatomedin C and alkaline phosphatase.

    PubMed

    Casser, H R; Zilkens, K W; Forst, R; Brüggemann, A

    1990-01-01

    After animal experiments suggested there was an interaction between growth hormone and bone healing, our aim in this paper was to ascertain whether there were any changes or possible interaction between the serum level of growth hormone, somatomedin C and alkaline phosphatase while a fractured bone was healing. To this end, the serum concentrations of growth hormone, somatomedin C, alkaline phosphatase and calcium were ascertained both pre- and post-operatively in two groups of patients--one with bone operations, the other with soft-tissue operations--and the results were compared. Comparing the groups, we found that after bone operations there was no increase in the serum level of growth hormone, nor of somatomedin C. An increase would have implied that these two hormones are directly involved in bone regeneration. There was no change in the serum level of alkaline phosphatase or calcium after either bone or soft-tissue operations.

  12. Sex differences in fuel use and metabolism during development in fasting juvenile northern elephant seals.

    PubMed

    Kelso, Elizabeth J; Champagne, Cory D; Tift, Michael S; Houser, Dorian S; Crocker, Daniel E

    2012-08-01

    Many polygynous, capital breeders exhibit sexual dimorphism with respect to body size and composition. Sexual dimorphism is often facilitated by sex differences in foraging behavior, growth rates and patterns of nutrient deposition during development. In species that undergo extended fasts during development, metabolic strategies for fuel use have the potential to influence future reproductive success by directly impacting somatic growth and acquisition of traits required for successful breeding. We investigated sexual dimorphism associated with metabolic strategies for fasting in developing northern elephant seals. Thirty-one juvenile seals of both sexes were sampled over extended fasts during annual autumn haul-outs. Field metabolic rate (FMR) and the contribution of protein catabolism to energy expenditure were estimated from changes in mass and body composition over 23±5 days of fasting (mean ± s.d.). Protein catabolism was assessed directly in a subset of animals based on urea flux at the beginning and end of the fast. Regulatory hormones and blood metabolites measured included growth hormone, cortisol, thyroxine, triiodothyronine, insulin, glucagon, testosterone, estradiol, glucose, urea and β-hydroxybutyrate. Males exhibited higher rates of energy expenditure during the fast but spared body protein stores more effectively than females. Rates of protein catabolism and energy expenditure were significantly impacted by hormone levels, which varied between the sexes. These data suggest that sex differences in fuel metabolism and energy expenditure during fasting arise early in juvenile development and may play an important role in the development of adult traits associated with reproductive success.

  13. Juvenile Delinquency: An Introduction

    ERIC Educational Resources Information Center

    Smith, Carolyn A.

    2008-01-01

    Juvenile Delinquency is a term which is often inaccurately used. This article clarifies definitions, looks at prevalence, and explores the relationship between juvenile delinquency and mental health. Throughout, differences between males and females are explored. (Contains 1 table.)

  14. Juvenile Arrests, 2007. Juvenile Justice Bulletin

    ERIC Educational Resources Information Center

    Puzzanchera, Charles

    2009-01-01

    This Bulletin summarizes 2007 juvenile crime and arrest data reported by local law enforcement agencies across the country and cited in the FBI report, "Crime in the United States 2007." The Bulletin describes the extent and nature of juvenile crime that comes to the attention of the justice system. It serves as a baseline for comparison for…

  15. Juvenile Arrests, 2000. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    This bulletin examines the national and state juvenile arrest rate in 2000 using data reported annually by local law enforcement agencies nationwide to the FBI's Uniform Crime Reporting program. Results indicate that the murder rate in 2000 was the lowest since 1965; juvenile arrests for violence in 2000 were the lowest since 1988; few juveniles…

  16. Juvenile Arrests, 1999. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    This bulletin presents a summary and analysis of national and state juvenile arrest data for 1999. Data come from the FBI's annual "Crime in the United States" report, which offers the estimated number of crimes reported to law enforcement agencies. The 1999 murder rate was the lowest since 1966. Of the nearly 1,800 juveniles murdered in…

  17. Juvenile Arrests 1996. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    In 1996, law enforcement agencies in the United States made an estimated 2.9 million arrests of persons under the age of 18. According to Federal Bureau of Investigation (FBI) figures, juveniles accounted for 19% of all arrests and 19% of all violent crime in 1996. The substantial growth in juvenile crime that began in the late 1980s peaked in…

  18. Juvenile Arrests, 1998. Juvenile Justice Bulletin.

    ERIC Educational Resources Information Center

    Snyder, Howard N.

    This report provides a summary and analysis of national and state juvenile arrest data in the United States. In 1998, law enforcement agencies made an estimated 2.6 million arrests of persons under age 18. Federal Bureau of Investigations statistics indicate that juveniles account for 18% of all arrests, and 17% of all violent crime arrests in…

  19. Juvenile Justice Glossary.

    ERIC Educational Resources Information Center

    Update on Law-Related Education, 2000

    2000-01-01

    Provides a list of terms pertaining to the juvenile justice system, such as appeal and due process, that are used throughout this edition of "Update on Law-Related Education," in particular, with the teaching strategies "The Case of Gerry Gault" (SO 532 196) "Today's Juvenile Court" (SO 532 197), and "Using the Juvenile Justice Poster" (SO 532…

  20. Concepts Shaping Juvenile Justice

    ERIC Educational Resources Information Center

    White, Rob

    2008-01-01

    Rob White's paper explores ways in which community building can be integrated into the practices of juvenile justice work. He provides a model of what can be called "restorative social justice", one that builds upon the juvenile conferencing model by attempting to fuse social justice concerns with progressive juvenile justice practices.

  1. Influence of hormone supplementation therapy on the incidence of denture stomatitis and on chemiluminescent activity of polymorphonuclear granulocytes in blood of menopausal-aged women

    PubMed Central

    2010-01-01

    Background Menopause is a health and social problem that affects a large number of women. Inadequate quantity of steroid hormones also impacts quality of the mucous membrane of the oral cavity. During menopausal age, many women wear removable prosthetic restorations in order to replace missing teeth. Such restorations may facilitate the development of inflammations in the surface of the oral cavity, referred to as denture stomatitis. Objective The aim of the study was to evaluate the influence of hormone supplementation therapy on the incidence of Candida-associated denture stomatitis and on the metabolic activity of polymorphonuclear granulocytes in peripheral blood of female patients. Materials and methods The study was conducted on a group of women in menopausal age, users of hormone replacement therapy and of removable prosthetic restorations. Female patients were subjected to a clinical study that included interviews and physical examinations. Laboratory microbiological examinations were completed on the basis of direct swabs collected from the mucous membrane of the oral cavity and from the surface of dentures. Metabolic activity of polymorphonuclear granulocytes in peripheral blood of female patients was evaluated by means of a chemiluminescence test. Results Candida-associated denture stomatitis observed was characterized by a strong growth of fungi and a lower chemiluminescent activity of neutrophils in blood of female patients undergoing hormone supplementation therapy. Conclusions Patients using hormone supplementation therapy and removable prosthetic restorations constitute a high-risk group for Candida infections and inflammations of the mucous membrane of the oral cavity; thus they should remain under constant dental control. PMID:21147619

  2. The influence of steroid sex hormones on the cognitive and emotional processing of visual stimuli in humans.

    PubMed

    Little, Anthony C

    2013-10-01

    Steroid sex hormones are responsible for some of the differences between men and women. In this article, I review evidence that steroid sex hormones impact on visual processing. Given prominent sex-differences, I focus on three topics for sex hormone effects for which there is most research available: 1. Preference and mate choice, 2. Emotion and recognition, and 3. Cerebral/perceptual asymmetries and visual-spatial abilities. For each topic, researchers have examined sex hormones and visual processing using various methods. I review indirect evidence addressing variation according to: menstrual cycle phase, pregnancy, puberty, and menopause. I further address studies of variation in testosterone and a measure of prenatal testosterone, 2D:4D, on visual processing. The most conclusive evidence, however, comes from experiments. Studies in which hormones are administrated are discussed. Overall, many studies demonstrate that sex steroids are associated with visual processing. However, findings are sometimes inconsistent, differences in methodology make strong comparisons between studies difficult, and we generally know more about activational than organizational effects.

  3. ALTERED HISTOLOGY OF THE THYMUS AND SPLEEN IN CONTAMINANT-EXPOSED JUVENILE AMERICAN ALLIGATORS

    EPA Science Inventory

    Morphological difference in spleen and thymus are closely related to functional immune differences. Hormonal regulation of the immune system has been demonstrated in reptilian splenic and thymic tissue. Spleens and thymus were obtained from juvenile alligators at two reference si...

  4. Soldier caste influences on candidate primer pheromone levels and juvenile hormone-dependent caste differentiation in workers of the termite Reticulitermes flavipes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Caste systems and the division of labor they make possible are common underlying features of all social insects. Multiple extrinsic factors have been shown to impact caste differentiation; for example, primer pheromones are chemical signaling molecules produced by certain castes that impact developm...

  5. Influence of adrenocorticotrophin hormone challenge and external factors (age, sex, and body region) on hair cortisol concentration in Canada lynx (Lynx canadensis).

    PubMed

    Terwissen, C V; Mastromonaco, G F; Murray, D L

    2013-12-01

    Land use changes are a significant factor influencing the decline of felid populations. However, additional research is needed to better understand how these factors influence populations in the wild. Hormone analysis can provide valuable information on the basic physiology and overall health of an animal, and enzyme immunoassays (EIA) are generally used for hair hormone analysis but must first be validated for the substrate of choice and species of interest. To date, hormone assays from hair have not been validated for Felidae, despite that the method holds considerable promise for non-invasive sampling of free-ranging animals. We sought to: (1) evaluate whether increased adrenocorticotrophin hormone (ACTH) during the period of hair growth results in elevated hair cortisol; (2) validate the enzyme immunoassay used; and (3) identify any variations in hair cortisol between age, sex and body regions, using Canada lynx. We quantified hair cortisol concentrations in captive animals through an ACTH challenge and collected samples from legally harvested lynx to compare variability between body regions. An EIA was validated for the analysis of hair cortisol. Lynx (n=3) had a qualitative increase in hair cortisol concentration following an ACTH challenge in captive animals (20 IU/kg of body weight weekly for 5 weeks), thereby supporting the use of an EIA to quantify cortisol values in hair. Based on our analysis of sampled lynx pelts, we found that hair cortisol did not vary between age and sex, but varied within the foot/leg region to a greater extent than between individuals. We recommend that future studies identify a standardized location for hair cortisol sampling.

  6. Hormone Therapy

    MedlinePlus

    ... estrogen , a hormone that helps control the menstrual cycle . Changing estrogen levels can bring on symptoms such ... two hormones—estrogen and progesterone —control your menstrual cycle. These hormones are made by the ovaries . Estrogen ...

  7. Performance and physiology of steers grazing toxic tall fescue as influenced by feeding soybean hulls and implanting with steroid hormones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A grazing experiment with steers grazing toxic tall fescue indicated that feeding pelleted soybean hulls in conjunction with steroid hormone implants can increase steer weight gain, and feeding soyben hulls can reduce the severity of fescue toxicosis Ergot alkaloids produced by a fungal endophyte...

  8. [Influence of ecdysteron-80 on the hormonal-mediator balance and lipid metabolism in rats with chronic cardiac failure].

    PubMed

    Fedorov, V N; Pynegova, N V

    2009-01-01

    Administration of ecdysteron-80 made of Serratula coronata L. to rats with experimental chronic cardiac failure partially corrects hormonal and mediator imbalance typical for this pathology. By some parameters this correction is full. By improving lipid metabolism, ecdysteron-80 reduces blood plasma atherogenicity.

  9. Influence of dioxin exposure upon levels of prostate-specific antigen and steroid hormones in Vietnamese men.

    PubMed

    Sun, Xian Liang; Kido, Teruhiko; Honma, Seijiro; Okamoto, Rie; Manh, Ho Dung; Maruzeni, Shoko; Nishijo, Muneko; Nakagawa, Hideaki; Nakano, Takeshi; Koh, Eitetsu; Takasuga, Takumi; Nhu, Dang Duc; Hung, Nguyen Ngoc; Son, Le Ke

    2016-04-01

    Most studies on the relationship between Agent Orange and prostate cancer have focused on US veterans of the Vietnam War. There have been few studies focusing on the relationship between levels of prostate-specific antigen (PSA) and dioxins or steroid hormones in Vietnamese men. In 2009-2011, we collected blood samples from 97 men who had resided in a "dioxin hotspot" and 85 men from a non-sprayed region in Vietnam. Then levels of PSA, dioxins, and steroid hormones were analyzed. Levels of most dioxins, furans, and non-ortho polychlorinated biphenyls were higher in the hotspot than those in the non-sprayed region. Levels of testosterone, dehydroepiandrosterone, and estradiol differed significantly between the hotspot and the non-sprayed region, but there were no correlations between levels of PSA and steroid hormones and dioxins in either of the two regions. Our findings suggest that PSA levels in Vietnamese men are not associated with levels of dioxin or steroid hormones in these two regions.

  10. Influence of hormonal replacement on the ventral lobe of the prostate of rats (Rattus norvegicus albinus) submitted to chronic ethanol treatment.

    PubMed

    Sáttolo, S; Carvalho, C A F; Cagnon, V H A

    2004-12-01

    The harmful influence of the chronic alcohol ingestion on the male reproductive system leads to important alterations including hypogonadism and feminization, besides the morphological and functional disorganization of the different sexual glands. So, the aim of this study was to analyse the structural changes on the ventral lobe of the prostate of rats with hormonal replacement associated to chronic alcohol ingestion. A total of 30 rats (Rattus norvegicus albinus) was divided into three groups: control-received water; alcoholic-received ethanol diluted to 20% and hormone-treated alcoholic-received ethanol diluted to 20% associated with the administering of testosterone (5mg/kg of weight) during the last 30 days of treatment. After 150 days of treatment, the animals were sacrificed, the prostate removed and submitted to transmission and scanning electron microscopies, histochemical analysis for acid phosphatase, testosterone level and stereologic analysis. In the alcoholic group the results demonstrated reduction of the total cellular volume and disorganization of the organelles involved in the secretory process. It was characterized a partial recovery of the cellular volume after treatment with testosterone. It was concluded that the ethanol impaired the cellular morphology and the hormonal replacement by itself did not bring about efficient remodeling of the organelles responsible for the secretory process.

  11. Effects of chromosomal sex and hormonal influences on shaping sex differences in brain and behavior: Lessons from cases of disorders of sex development.

    PubMed

    Bramble, Matthew S; Lipson, Allen; Vashist, Neerja; Vilain, Eric

    2017-01-02

    Sex differences in brain development and postnatal behavior are determined largely by genetic sex and in utero gonadal hormone secretions. In humans however, determining the weight that each of these factors contributes remains a challenge because social influences should also be considered. Cases of disorders of sex development (DSD) provide unique insight into how mutations in genes responsible for gonadal formation can perturb the subsequent developmental hormonal milieu and elicit changes in normal human brain maturation. Specific forms of DSDs such as complete androgen insensitivity syndrome (CAIS), congenital adrenal hyperplasia (CAH), and 5α-reductase deficiency syndrome have variable effects between males and females, and the developmental outcomes of such conditions are largely dependent on sex chromosome composition. Medical and psychological works focused on CAH, CAIS, and 5α-reductase deficiency have helped form the foundation for understanding the roles of genetic and hormonal factors necessary for guiding human brain development. Here we highlight how the three aforementioned DSDs contribute to brain and behavioral phenotypes that can uniquely affect 46,XY and 46,XX individuals in dramatically different fashions. © 2016 Wiley Periodicals, Inc.

  12. Juveniles exposed to embryonic corticosterone have enhanced flight performance

    PubMed Central

    Chin, Eunice H.; Love, Oliver P.; Verspoor, Jan J.; Williams, Tony D.; Rowley, Kyle; Burness, Gary

    2008-01-01

    Exposure to maternally derived glucocorticoids during embryonic development impacts offspring phenotype. Although many of these effects appear to be transiently ‘negative’, embryonic exposure to maternally derived stress hormones is hypothesized to induce preparative responses that increase survival prospects for offspring in low-quality environments; however, little is known about how maternal stress influences longer-term survival-related performance traits in free-living individuals. Using an experimental elevation of yolk corticosterone (embryonic signal of low maternal quality), we examined potential impacts of embryonic exposure to maternally derived stress on flight performance, wing loading, muscle morphology and muscle physiology in juvenile European starlings (Sturnus vulgaris). Here we report that fledglings exposed to experimentally increased corticosterone in ovo performed better during flight performance trials than control fledglings. Consistent with differences in performance, individuals exposed to elevated embryonic corticosterone fledged with lower wing loading and had heavier and more functionally mature flight muscles compared with control fledglings. Our results indicate that the positive effects on a survival-related trait in response to embryonic exposure to maternally derived stress hormones may balance some of the associated negative developmental costs that have recently been reported. Moreover, if embryonic experience is a good predictor of the quality or risk of future environments, a preparative phenotype associated with exposure to apparently negative stimuli during development may be adaptive. PMID:18842541

  13. 195 EXPRESSION OF MESENCHYMAL STROMAL CELL (MSC) MARKERS IN THE EQUINE ENDOMETRIUM AND IN VITRO INFLUENCE OF STEROID HORMONES ON ENDOMETRIAL-DERIVED MSC.

    PubMed

    Rink, E; Kuhl, J; Aurich, C; French, H; Nino-Fong, R; Watson, E; Donadeu, F X

    2016-01-01

    Mesenchymal stromal cell (MSC) are multipotent precursor cells that have been isolated from many tissues, including endometrium in some species. These cells are necessary for tissue homeostasis, which in the cycling equine endometrium is regulated in part by changes in concentration of steroid hormones. The expression of oestrogen and progesterone receptors during the oestrous cycle has been studied before, but MSC gene expression is not reported as well as the effects of steroid hormones on in vitro proliferation of endometrial MSC. This study was designed to investigate the influence of steroid hormones on endometrial MSC proliferation in vitro and to examine mRNA expression of MSC markers (CD29, CD44, CD73, CD90, and CD105) in the healthy equine endometrium during the oestrous cycle. Equine endometrial tissue was collected postmortem (n=6) and digested using a dissociation medium and mucin-1-bound magnetic beads were utilised to remove epithelial cells from the resulting single-cell solution. The cells were expanded in culture and, at passage 4, incubated with 3 different concentrations of oestradiol and progesterone for 5 days. For the proliferation analysis the Alamar Blue® assay was used according to manufacturer instructions. Endometrial biopsies, for quantitative RT-PCR analysis, were taken from healthy mares (n=5) on Day 5 and 13 post-ovulation, during oestrus (1 follicle >3.5cm, pronounced uterine oedema), and seasonal anestrous (seasonal anovulation). The ΔCt values were used for statistical analysis using SPSS Statistics 22 (IBM Corp., Armonk, NY). Data for quantitative PCR are presented as gene expression relative to the mean of 18S and GAPDH. No significant differences in proliferation could be detected in the various groups incubated with steroid hormones compared with the controls supplemented with charcoal-stripped fetal bovine serum. Detectable levels of mRNA for all 5 MSC markers analysed were present throughout the oestrous cycle. While the

  14. THE VITAMIN D HORMONE: A MULTITUDE OF ACTIONS POTENTIALLY INFLUENCING THE PHYSICAL FUNCTION DECLINE IN OLDER PERSONS

    PubMed Central

    Cesari, Matteo; Incalzi, Raffaele Antonelli; Zamboni, Valentina; Pahor, Marco

    2015-01-01

    Vitamin D, a secosteroid (pro)-hormone, has been traditionally considered as a key regulator of bone metabolism, and calcium and phosphorous homeostasis through a negative feedback with the parathyroid hormone. However, during the last twenty years, the role played by vitamin D has been largely revised by recognizing it a pleiotropic action on a wide spectrum of systems, apparati, and tissues. Thus, vitamin D has growingly been involved as a primary determinant of biological modifications and specific clinical conditions. The effect of vitamin D on skeletal muscle and related outcomes (including physical function decline and disability) is surely one of the most relevant to study in the context of global aging. In the present review, the subclinical and clinical consequences of vitamin D deficiency/insufficiency, extremely frequent conditions in older age, are described. Special focus is given to skeletal muscle and physical function. Limitations of available scientific evidence on the topic are also discussed. PMID:21134097

  15. Do dietary phytoestrogens influence susceptibility to hormone-dependent cancer by disrupting the metabolism of endogenous oestrogens?

    PubMed

    Kirk, C J; Harris, R M; Wood, D M; Waring, R H; Hughes, P J

    2001-05-01

    Phytoestrogens are natural constituents of our diets that have been suggested to protect against hormone-dependent breast cancer. Some of the diverse effects of these compounds may be attributed to ligand-dependent differences in their interaction with oestrogen receptor sub-classes. However, phytoestrogens can also inhibit enzymes that are involved in the generation and removal of endogenous steroid hormones. Among the most potent effects of dietary phytoestrogens is their ability to inhibit the sulphotransferases that sulphate both oestrogenic steroids and a variety of environmental chemicals, including dietary pro-carcinogens. Circulating steroid sulphates are thought to be the major source of oestradiol in post-menopausal breast tumours and sulphation is a key step in the activation of some dietary pro-carcinogens. Hence the inhibition of sulphotransferases by dietary phytoestrogens may have complex effects upon human susceptibility to breast cancer.

  16. Influence of 50 Hz magnetic field on sex hormones and other fertility parameters of adult male rats.

    PubMed

    Al-Akhras, Moh'd-Ali; Darmani, Homa; Elbetieha, Ahmed

    2006-02-01

    The effects of an extremely low frequency (ELF) magnetic field on the sex hormones and other fertility parameters of adult male Sprague-Dawley rats were investigated. Adult male rats were exposed to a 50 Hz sinusoidal magnetic field at approximately 25 microT (rms) for 18 consecutive weeks. There were no significant effects on the absolute body weight and the weight of the testes of the exposed rats. However, the weights of seminal vesicles and preputial glands were significantly reduced in the exposed male rats. Similarly, a significant reduction in sperm count was observed in the exposed group. Furthermore, there were no significant effects on the serum levels of male follicle stimulating hormone (FSH) during the 18 weeks of exposure period. On the other hand, there was a significant increase in the serum levels of male luteinizing hormone (LH) after 18 weeks of exposure (P < .005), while testosterone levels were significantly decreased only after 6 and 12 weeks of the exposure period. These results suggest that long term exposure to ELF could have adverse effects on mammalian fertility and reproduction.

  17. Influence of sex hormone levels on gingival enlargement in adolescent patients undergoing fixed orthodontic therapy: A pilot study

    PubMed Central

    Hosadurga, Rajesh; Nabeel Althaf, M. S.; Hegde, Shashikanth; Rajesh, Kashyap S.; Arun Kumar, M. S.

    2016-01-01

    Background: Sex hormones may be a modifying factor in the periodontal disease pathogenesis. Aim: The association between gingival enlargement and sex hormone levels in adolescent patients undergoing fixed orthodontic therapy needs to be determined. Settings and Design: This study was conducted in the Department of Periodontology in association with the Department of Orthodontics, Yenepoya Dental College, Yenepoya University, Mangaluru. Materials and Methods: A pilot study was conducted on 21 adolescent patients between the age group of 13–19 years, who had undergone fixed orthodontic therapy for at least 3 months. Apicocoronally, the gingival enlargement was assessed by the index described by Miller and Damm. Miranda and Brunet index was used to assess gingival overgrowth in the buccal–lingual direction in the interdental papilla. Furthermore, the patients were assigned to two groups - Group 1-GE and Group 2-non-GE. Sex hormones assessed were estradiol and progesterone in females and testosterone in males in both groups. Results: 57.1% of the study population had enlargement of the gingiva. The mean plaque score was 0.59 and 0.56, respectively, in both groups. A statistically significant relationship was found between estradiol and testosterone levels with gingival enlargement. However, a significant relationship was not obtained for progesterone levels with the gingival enlargement. Conclusion: Direct correlation between estradiol, testosterone, and gingival enlargement was seen. PMID:27994419

  18. Short-Period Influence of Chronic Morphine Exposure on Serum Levels of Sexual Hormones and Spermatogenesis in Rats

    PubMed Central

    Ahmadnia, Hasan; Akhavan Rezayat, Alireza; Hoseyni, Mahmood; Sharifi, Nooriye; Khajedalooee, Mohhamad; Akhavan Rezayat, Arash

    2016-01-01

    Background Increased rates of addiction and its broad societal complications are well known. One of the most important systems that may malfunction in drug abusers is the reproductive system, and evaluating patients for this potential risk may lead to increased awareness. Materials and Methods Thirty 60-day-old male rats were divided into control and target groups. The target group underwent 5 mg/kg intraperitoneal injections of morphine twice a day while the control group underwent normal saline injections (at the same dosage). After 60 days, the rats were anesthetized, and after blood sampling, they underwent bilateral orchiepididymectomy. Histological and hormonal evaluations were performed on the samples. Results Levels of sex hormonal features and spermatogenesis were significantly reduced in the target group compared to the control group. LH levels showed a meaningful decrease in the target group, but FSH and testosterone levels did not. On histological section analysis, mature sperm were meaningfully decreased in the target group. Conclusions Chronic use of opioids may lead to alterations in sexual features and sexual hormones. Therefore, opioids have the potential to cause infertility. These changes may result from the effect of the drugs on the hypophysis or hypothalamus, the direct effect of the drugs on the seminiferous tubules, or a combination of both. The findings suggest that public awareness about addiction may cause decreased infertility rates. PMID:27713869

  19. Neural Activation During Mental Rotation in Complete Androgen Insensitivity Syndrome: The Influence of Sex Hormones and Sex Chromosomes.

    PubMed

    van Hemmen, Judy; Veltman, Dick J; Hoekzema, Elseline; Cohen-Kettenis, Peggy T; Dessens, Arianne B; Bakker, Julie

    2016-03-01

    Sex hormones, androgens in particular, are hypothesized to play a key role in the sexual differentiation of the human brain. However, possible direct effects of the sex chromosomes, that is, XX or XY, have not been well studied in humans. Individuals with complete androgen insensitivity syndrome (CAIS), who have a 46,XY karyotype but a female phenotype due to a complete androgen resistance, enable us to study the separate effects of gonadal hormones versus sex chromosomes on neural sex differences. Therefore, in the present study, we compared 46,XY men (n = 30) and 46,XX women (n = 29) to 46,XY individuals with CAIS (n = 21) on a mental rotation task using functional magnetic resonance imaging. Previously reported sex differences in neural activation during mental rotation were replicated in the control groups, with control men showing more activation in the inferior parietal lobe than control women. Individuals with CAIS showed a female-like neural activation pattern in the parietal lobe, indicating feminization of the brain in CAIS. Furthermore, this first neuroimaging study in individuals with CAIS provides evidence that sex differences in regional brain function during mental rotation are most likely not directly driven by genetic sex, but rather reflect gonadal hormone exposure.

  20. Influence of substituting dietary soybean for air-classified sunflower (Helianthus annuus L.) meal on egg production and steroid hormones in early-phase laying hens.

    PubMed

    Laudadio, V; Ceci, E; Nahashon, S N; Introna, M; Lastella, N M B; Tufarelli, V

    2014-02-01

    Soybean meal (SBM) is the most widely and expensive protein source used in the formulation of poultry diets; however, when the price of SBM increases, poultry nutritionists seek alternative sources that are more economical in formulating least-cost rations. This research aimed to evaluate the effects of dietary air-classified sunflower meal (SFM) on some productive parameters and plasma steroid hormones in laying hens. In this trial, 20-week-old laying hens (ISA Brown strain) in the early phase of production were randomly assigned to two groups and fed wheat middlings-based diets containing soybean (135 g/kg; 48% CP) or air-classified SFM (160 g/kg; 41% CP) as the main protein source. Laying performance, egg size and feed conversion ratio were evaluated for 10 week. Plasma steroid hormones (progesterone and oestradiol) in the hens were quantified weekly. Substituting SBM with air-classified SFM did not change (p > 0.05) the hens' growth performance, whereas feed consumption and efficiency were positively influenced (p < 0.05) by SFM treatment. Egg production rate was improved in hens fed the SFM diet (p < 0.05), as well as the percentage of medium-size eggs that was higher for SFM treatment (p < 0.05). Steroid hormones levels were affected by dietary treatment (p < 0.01). From our findings, it could be effective to include air-classified SFM in early-phase laying hen diets as an alternative protein source substituting SBM, without negative influence on productive performance and egg traits, reducing also the production costs.

  1. Daily rhythms of the expression of genes from the somatotropic axis: The influence on tilapia (Oreochromis niloticus) of feeding and growth hormone administration at different times.

    PubMed

    Costa, Leandro S; Rosa, Priscila V; Fortes-Silva, Rodrigo; Sánchez-Vázquez, F Javier; López-Olmeda, Jose F

    2016-01-01

    The aim of this research was to investigate the presence of daily rhythms in the somatotropic axis of tilapia fed at two times (mid-light, ML or mid-dark, MD) and the influence of the time of day of growth hormone (GH) administration on the response of this axis. Two different GH injection times were tested: ZT 3 (3h after lights on) and ZT 15 (3h after lights off). In both experiments, the mRNA expression levels of hypothalamic pituitary adenylate cyclase-activating polypeptide (pacap), pituitary growth hormone (gh), liver insulin-like growth factors (igf1 and igf2a), and liver and muscle growth hormone receptors (ghr1 and ghr2) and IGF receptors (igf1ra and igf2r) were evaluated by means of qPCR. Daily rhythms were observed in the liver for ghr1, ghr2 and igf2r but only in fish fed at ML, with the acrophases located in the light phase (ZT 3:30, 3:31 and 7:38 h, respectively). In the muscle, ghr1 displayed a significant rhythm in both groups and ghr2 in ML fed fish (acrophases at ZT 5:29, 7:14 and 9:23h). The time of both GH administration and feeding influenced the response to GH injection: ML fed fish injected with GH at ZT 15 h showed a significant increase in liver igf1, igf2a and ghr2; and muscle ghr2 expression. This is the first report that describes the existence of daily rhythms in the somatotropic axis of tilapia and its time-dependent responses of GH administration. Our results should be considered when investigating the elements of the somatotropic axis in tilapia and GH administration.

  2. Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada.

    PubMed

    Rincón, Beatriz; Kenchington, Ellen L

    2016-01-01

    We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km-all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna.

  3. Influence of Benthic Macrofauna as a Spatial Structuring Agent for Juvenile Haddock (Melanogrammus aeglefinus) on the Eastern Scotian Shelf, Atlantic Canada

    PubMed Central

    2016-01-01

    We examined the habitat of juvenile haddock on the eastern Scotian Shelf (off Nova Scotia, Canada) in relation to grab-sampled benthic macrofaunal invertebrate species assemblages in order to determine whether there were significant differences in benthic macrofauna between areas of historically persistent high and low juvenile haddock abundance. Our analyses were conducted over two spatial scales in each of two years: among banks (Emerald, Western and Sable Island), approximately 60 km distant from each other, and between areas of high and low juvenile haddock abundance at distances of 10 to 30 km–all in an area that had not experienced groundfishing in the decade prior to sampling. We also examined fine-scale (10s of metres) within-site variability in the macrofauna and used surficial sediment characteristics, along with hydrographic variables, to identify environmental correlates. PERMANOVA identified statistically significant differences in biomass, density and composition of the benthos associated with juvenile haddock abundance; however it was difficult to determine whether the results had biological relevance. Post hoc tests showed that these differences occurred only on Sable Island Bank where both fish and benthos may have been independently responding to sediment type which was most different there (100% sand in the area of low haddock abundance vs. 22% gravel in the area of high haddock abundance). In total, 383 benthic taxa representing 13 phyla were identified. Annelida was the most specious phylum (36.29% of taxa, representing 33 families), followed by Arthropoda (with Crustaceans, mostly Amphipoda, accounting for 25.07% of the total number of taxa). The strongest pattern in the macrofauna was expressed at the largest scale, between banks, accounting for approximately 25% of the variation in the data. Emerald Bank, deeper, warmer and saltier than the Western and Sable Island Banks, had a distinctive fauna. PMID:27649419

  4. Movements of juvenile common ravens in an arid landscape

    USGS Publications Warehouse

    Webb, W.C.; Boarman, W.I.; Rotenberry, J.T.

    2009-01-01

    Movement patterns of juvenile birds are poorly understood, yet critically important ecological phenomena, especially for species with a prolonged juvenile period. We evaluated postfledging movements of juvenile common ravens (Corvus corax) in a western Mojave Desert landscape composed of a mosaic of natural and anthropogenic elements. Generally, ravens do not begin breeding until after their fourth year. We marked 2 annual cohorts of juvenile ravens and followed them from dispersal from their natal territory for up to 33 months. Movements of juvenile common ravens were similar for males and females. Conspecifics and confined livestock feeding operations represented important resources for juvenile ravens, and juveniles were rarely located in open desert. However, initial movements from the natal territory to the nearest communal point subsidy rather than the closest anthropogenic resource suggested juvenile dispersal was influenced by the combination of conspecifics and anthropogenic resources, rather than the distribution of those resources. Land managers concerned with growing raven populations should reduce access to concentrated anthropogenic resources such as landfills and dairies, which serve as important resources for juveniles. Because juvenile ravens rarely venture into open desert, reducing their numbers by lethal removal or other means is unlikely to lessen raven predation of desert tortoises (Gopherus agassizii).

  5. Renewing Juvenile Justice

    ERIC Educational Resources Information Center

    Macallair, Daniel; Males, Mike; Enty, Dinky Manek; Vinakor, Natasha

    2011-01-01

    The Center on Juvenile and Criminal Justice (CJCJ) was commissioned by Sierra Health Foundation to critically examine California's juvenile justice system and consider the potential role of foundations in promoting systemic reform. The information gathered by CJCJ researchers for this report suggests that foundations can perform a key leadership…

  6. Juvenile Delinquency Intervention.

    ERIC Educational Resources Information Center

    Lipsey, Mark W.

    1988-01-01

    Three meta-analyses by C. J. Garrett (1984, 1985), P. Kaufman (1985), and W. S. Davidson and others (1984) of juvenile delinquency interventions are summarized. This systematic literature review indicates that interventions to reduce juvenile delinquency may have small, but meaningful, impacts. Promising avenues for future research are suggested.…

  7. Juvenile Confinement in Context

    ERIC Educational Resources Information Center

    Mendel, Richard A.

    2012-01-01

    For more than a century, the predominant strategy for the treatment and punishment of serious and sometimes not-so-serious juvenile offenders in the United States has been placement into large juvenile corrections institutions, alternatively known as training schools, reformatories, or youth corrections centers. America's heavy reliance on…

  8. Distinguishing juvenile homicide from violent juvenile offending.

    PubMed

    DiCataldo, Frank; Everett, Meghan

    2008-04-01

    Juvenile homicide is a social problem that has remained a central focus within juvenile justice research in recent years. The term juvenile murderer describes a legal category, but it is purported to have significant scientific meaning. Research has attempted to conceptualize adolescent murderers as a clinical category that can be reliably distinguished from their nonhomicidal counterparts. This study examined 33 adolescents adjudicated delinquent or awaiting trial for murder and 38 adolescents who committed violent, nonhomicidal offenses to determine whether the two groups differed significantly on family history, early development, delinquency history, mental health, and weapon possession variables. The nonhomicide group proved more problematic on many of these measures. Two key factors did distinguish the homicide group: These adolescents endorsed the greater availability of guns and substance abuse at the time of their commitment offenses. The significance of this finding is discussed, and the implications for risk management and policy are reviewed.

  9. Influence of Spinal and General Anesthesia on the Metabolic, Hormonal, and Hemodynamic Response in Elective Surgical Patients

    PubMed Central

    Milosavljevic, Snezana B.; Pavlovic, Aleksandar P.; Trpkovic, Sladjana V.; Ilić, Aleksandra N.; Sekulic, Ana D.

    2014-01-01

    Background The aim of the study was to determine the significance of spinal anesthesia in the suppression of the metabolic, hormonal, and hemodynamic response to surgical stress in elective surgical patients compared to general anesthesia. Material/Methods The study was clinical, prospective, and controlled and it involved 2 groups of patients (the spinal and the general anesthesia group) who underwent the same surgery. We monitored the metabolic and hormonal response to perioperative stress based on serum cortisol level and glycemia. We also examined how the different techniques of anesthesia affect these hemodynamic parameters: systolic arterial pressure (AP), diastolic AP, heart rate (HR), and arterial oxygen saturation (SpO2). These parameters were measured before induction on anesthesia (T1), 30 min after the surgical incisions (T2), 1 h postoperatively (T3) and 24 h after surgery (T4). Results Serum cortisol levels were significantly higher in the general anesthesia group compared to the spinal anesthesia group (p<0.01). Glycemia was significantly higher in the general anesthesia group (p<0.05). There was a statistically significant, positive correlation between serum cortisol levels and glycemia at all times observed (p<0.01). Systolic and diastolic AP did not differ significantly between the groups (p=0.191, p=0.101). The HR was significantly higher in the general anesthesia group (p<0.01). SpO2 values did not differ significantly between the groups (p=0.081). Conclusions Based on metabolic, hormonal, and hemodynamic responses, spinal anesthesia proved more effective than general anesthesia in suppressing stress response in elective surgical patients. PMID:25284266

  10. Influence of music on steroid hormones and the relationship between receptor polymorphisms and musical ability: a pilot study

    PubMed Central

    Fukui, Hajime; Toyoshima, Kumiko

    2013-01-01

    Studies have shown that music confers plasticity to the brain. In a preliminary pilot study, we examined the effect of music listening on steroid hormones and the relationship between steroid hormone receptor polymorphisms and musical ability. Twenty-one subjects (10 males and 11 females) were recruited and divided into musically talented and control groups. The subjects selected (1) music they preferred (chill-inducing music) and (2) music they did not like. Before and after the experiments, saliva was collected to measure the levels of steroid hormones such as testosterone, estradiol, and cortisol. DNA was also isolated from the saliva samples to determine the androgen receptor (AR) and arginine vasopressin receptor 1A genotypes. Advanced Measures of Music Audiation (AMMA) was used to determine the musical ability of the subjects. With both types of music, the cortisol levels decreased significantly in both sexes. The testosterone (T) levels declined in males when they listened to both types of music. In females, the T levels increased in those listening to chill-inducing music but declined when they listened to music they disliked. However, these differences were not significant. The 17-beta estradiol levels increased in males with both types of music, whereas the levels increased with chill-inducing music but declined with disliked music in females. The AMMA scores were higher for the short repeat length-type AR than for the long repeat length-type. Comparisons of AR polymorphisms and T levels before the experiments showed that the T levels were within the low range in the short repeat length-type group and there was a positive relationship with the repeat length, although it was not significant. This is the first study conducted in humans to analyze the relationships between the AR gene, T levels, and musical ability. PMID:24348454

  11. Influence of Dietary Copper on Serum Growth-Related Hormone Levels and Growth Performance of Weanling Pigs.

    PubMed

    Wang, Jianguo; Zhu, Xiaoyan; Guo, Yazhou; Wang, Zhe; Zhao, Baoyu; Yin, Yunhou; Liu, Guowen

    2016-07-01

    To investigate the effect of dietary copper on serum growth-related hormones levels and growth performance, a total of 60 weanling pigs were randomly assigned to six groups each containing 10 pigs, fed on basal diets supplemented with 0 (control), 100, 150, 200, 250, and 300 mg/kg copper sulfate for 80 days, respectively. The average daily gain (ADG), feed to gain ratio (F/G), feed intake and serum growth hormone (GH), insulin (INS), insulin-like growth factor 1 (IGF-1), and insulin-like growth factor-binding protein 3 (IGFBP-3) levels were detected at interval of 20 days. The results revealed that ADG, and serum GH, INS, IGF-1, and IGFBP-3 concentrations were increased significantly in the pigs fed on diets added with 100, 150, 200, 250, and 300 mg/kg copper sulfate. Meanwhile, in the pigs supplemented with 250 mg/kg copper sulfate, ADG was increased significantly from the 40th to the 60th day of the experiment (P < 0.01), and the levels of GH, INS, IGF-1, and IGFBP-3 in serum were elevated significantly from the 20th to the 40th day of the experiment (P < 0.01). It is concluded that effects of copper supplemented in the diet on the growth of pigs were related to the increasing levels of GH, INS, IGF-1, and IGFBP-3 in serum which were induced by copper. High dietary copper increase the concentrations of growth-related hormones in serum, resulting in improving the growth performance of weanling pigs.

  12. The influence of medical education level on the Jagiellonian University Collegium Medicum medical students' knowledge concerning oral hormonal contraceptive pills.

    PubMed

    Polak, Karina; Pityński, Kazimierz; Banaś, Tomasz; Bubel, Magdalena; Kałwa, Maria; Jamroga, Joanna; Knysak, Magdalena; Kusior, Magdalena; Truszkiewicz, Katarzyna; Oleksy, Piotr

    2016-01-01

    In December 2014 the authors carried out a research among Jagiellonian University Collegium Medicum medical students in a form of a questionnaire which consisted of two parts: personal information and multiple choice test concerning student's knowledge on OCPs. It showed that the level of medical education, defined as the year of study, increases student's knowledge about oral hormonal contraceptive pills. New program of study introduced from academic year 2012/2013 gives students wider knowledge on OCPs at earlier stage of education. Factors as female sex, usage of OCPs by student or his partner, positive attitude towards recommending OCPs to future patients show positive correlation with student's knowledge.

  13. Protein Hormones and Immunity‡

    PubMed Central

    Kelley, Keith W.; Weigent, Douglas A.; Kooijman, Ron

    2007-01-01

    A number of observations and discoveries over the past 20 years support the concept of important physiological interactions between the endocrine and immune systems. The best known pathway for transmission of information from the immune system to the neuroendocrine system is humoral in the form of cytokines, although neural transmission via the afferent vagus is well documented also. In the other direction, efferent signals from the nervous system to the immune system are conveyed by both the neuroendocrine and autonomic nervous systems. Communication is possible because the nervous and immune systems share a common biochemical language involving shared ligands and receptors, including neurotransmitters, neuropeptides, growth factors, neuroendocrine hormones and cytokines. This means that the brain functions as an immune-regulating organ participating in immune responses. A great deal of evidence has accumulated and confirmed that hormones secreted by the neuroendocrine system play an important role in communication and regulation of the cells of the immune system. Among protein hormones, this has been most clearly documented for prolactin (PRL), growth hormone (GH), and insulin-like growth factor-1 (IGF-I), but significant influences on immunity by thyroid stimulating hormone (TSH) have also been demonstrated. Here we review evidence obtained during the past 20 years to clearly demonstrate that neuroendocrine protein hormones influence immunity and that immune processes affect the neuroendocrine system. New findings highlight a previously undiscovered route of communication between the immune and endocrine systems that is now known to occur at the cellular level. This communication system is activated when inflammatory processes induced by proinflammatory cytokines antagonize the function of a variety of hormones, which then causes endocrine resistance in both the periphery and brain. Homeostasis during inflammation is achieved by a balance between cytokines and

  14. The influence of natural short photoperiodic and temperature conditions on plasma thyroid hormones and cholesterol in male Syrian hamsters

    NASA Astrophysics Data System (ADS)

    Vaughan, M. K.; Brainard, G. C.; Reiter, R. J.

    1984-09-01

    Adult male Syrian hamsters were subjected to 1, 3, 5, 7 or 11 weeks of either natural winter conditions or rigorously controlled laboratory conditions (LD 10∶14; 22 ± 2‡C). Although both groups of hamsters gained weight over the course of the experiment, hamsters housed indoors were significantly heavier after 5 weeks of treatment compared to their outdoors counterparts. Animals housed under natural conditions exhibited a significant decrease in circulating levels of thyroxine (T4) and a rapid rise in triiodothyronine (T3) levels; the free T4 and free T3 index (FT4I and FT3I) mirrored the changes in circulating levels of the respective hormones. Laboratory-housed animals had a slight rise in T4 and FT4I at 3 weeks followed by a slow steady decline in these values; T3 and FT3I values did not change remarkably in these animals. Plasma cholesterol declined steadily over the course of the experiment in laboratory-maintained animals but increased slightly during the first 5 weeks in animals under natural conditions. Since the photoperiodic conditions were approximately of the same duration in these 2 groups, it is concluded that the major differences in body weight, thyroid hormone values and plasma cholesterol are due to some component (possibly temperature) in the natural environment.

  15. Influence of head-down bed rest on the circadian rhythms of hormones and electrolytes involved in hydroelectrolytic regulation

    NASA Technical Reports Server (NTRS)

    Millet, C.; Custaud, M. A.; Allevard, A. M.; Zaouali-Ajina, M.; Monk, T. H.; Arnaud, S. B.; Claustrat, B.; Gharib, C.; Gauquelin-Koch, G.

    2001-01-01

    We investigated in six men the impact of a 17-day head-down bed rest (HDBR) on the circadian rhythms of the hormones and electrolytes involved in hydroelectrolytic regulation. This HDBR study was designed to mimic an actual spaceflight. Urine samples were collected at each voiding before, during and after HDBR. Urinary excretion of aldosterone, arginine vasopressin (AVP), cyclic guanosine monophosphate (cGMP), cortisol, electrolytes (Na+ and K+) and creatinine were determined. HDBR resulted in a significant reduction of body mass (P < 0.01) and of caloric intake [mean (SEM) 2,778 (37) kcal.24 h(-1) to 2,450 (36) kcal.24 h(-1), where 1 kcal.h(-1) = 1.163 J.s(-1); P< 0.01]. There was a significant increase in diastolic blood pressure [71.8 (0.7) mmHg vs 75.6 (0.91) mmHg], with no significant changes in either systolic blood pressure or heart rate. The nocturnal hormonal decrease of aldosterone was clearly evident only before and after HDBR, but the day/night difference did not appear during HDBR. The rhythm of K+ excretion was unchanged during HDBR, whereas for Na+ excretion, a large decrease was shown during the night as compared to the day. The circadian rhythm of cortisol persisted. These data suggest that exposure to a 17-day HDBR could induce an exaggeration of the amplitude of the Na+ rhythm and abolition of the aldosterone rhythm.

  16. Influence of season on plasma antidiuretic hormone, angiotensin II, aldosterone and plasma renin activity in young volunteers.

    PubMed

    Kanikowska, Dominika; Sugenoya, Junichi; Sato, Maki; Shimizu, Yuuki; Inukai, Yoko; Nishimura, Naoki; Iwase, Satoshi

    2010-05-01

    We investigated seasonal changes in hormonal and thermoregulatory responses. Eight volunteers were subjected to the experiment at four times of the year: around the vernal and autumnal equinoxes, and at the summer and winter solstices at latitude 35 degrees N. Plasma antidiuretic hormone (ADH), angiotensin II (ANG II), aldosterone (ALD) and plasma renin activity (PRA) were analyzed before and after water immersion. Seasonal changes in thermoregulatory responses were assessed by measuring core temperature and sweat rate during immersion of the leg in hot water (at 42 degrees C) for 30 min in a room maintained at 26 degrees C. The concentration of plasma ADH and ALD before water immersion was significantly higher in summer than in other seasons. The concentrations of ANG II and PRA did not show seasonal variations. Changes in tympanic temperature during water immersion showed significant differences between seasons, and were higher in winter than in other seasons. The sweat rate was significantly higher in summer than in other seasons. In summary, ADH and ALD concentrations displayed a seasonal rhythm with marked elevation in summer; this may be a compensative mechanism to prevent dehydration from increased sweat loss during summer due to heat acclimatization.

  17. Estuarine Habitats for Juvenile Salmon in the Tidally-Influenced Lower Columbia River and Estuary : Reporting Period September 15, 2008 through May 31, 2009.

    SciTech Connect

    Baptista, António M.

    2009-08-02

    This work focuses on the numerical modeling of Columbia River estuarine circulation and associated modeling-supported analyses conducted as an integral part of a multi-disciplinary and multi-institutional effort led by NOAA's Northwest Fisheries Science Center. The overall effort is aimed at: (1) retrospective analyses to reconstruct historic bathymetric features and assess effects of climate and river flow on the extent and distribution of shallow water, wetland and tidal-floodplain habitats; (2) computer simulations using a 3-dimensional numerical model to evaluate the sensitivity of salmon rearing opportunities to various historical modifications affecting the estuary (including channel changes, flow regulation, and diking of tidal wetlands and floodplains); (3) observational studies of present and historic food web sources supporting selected life histories of juvenile salmon as determined by stable isotope, microchemistry, and parasitology techniques; and (4) experimental studies in Grays River in collaboration with Columbia River Estuary Study Taskforce (CREST) and the Columbia Land Trust (CLT) to assess effects of multiple tidal wetland restoration projects on various life histories of juvenile salmon and to compare responses to observed habitat-use patterns in the mainstem estuary. From the above observations, experiments, and additional modeling simulations, the effort will also (5) examine effects of alternative flow-management and habitat-restoration scenarios on habitat opportunity and the estuary's productive capacity for juvenile salmon. The underlying modeling system is part of the SATURN1coastal-margin observatory [1]. SATURN relies on 3D numerical models [2, 3] to systematically simulate and understand baroclinic circulation in the Columbia River estuary-plume-shelf system [4-7] (Fig. 1). Multi-year simulation databases of circulation are produced as an integral part of SATURN, and have multiple applications in understanding estuary

  18. Proline with or without hydroxyproline influences collagen concentration and regulates prolyl 4-hydroxylase α (I) gene expression in juvenile turbo ( Scophthalmus maximus L.)

    NASA Astrophysics Data System (ADS)

    Zhang, Kaikai; Mai, Kangsen; Xu, Wei; Zhou, Huihui; Liufu, Zhiguo; Zhang, Yanjiao; Peng, Mo; Ai, Qinghui

    2015-06-01

    This study was conducted to investigate the effect of dietary proline (Pro), and Pro and hydroxyproline (Hyp) in combination on the growth performance, total Hyp and collagen concentrations of tissues, and prolyl 4-hydroxylase α(I) (P4H α(I)) gene expression in juvenile turbot feeding high plant protein diets. A diet containing 50% crude protein and 12% crude lipid was formulated as the basal and control, on which other two protein and lipid contents identical experimental diets were formulated by supplementing the basal with either 0.75% Pro (Pro-0.75) or 0.75% Pro and 0.75% Hyp (Pro+Hyp). Four groups of fish in indoor seawater recirculating systems, 35 individuals each, were fed twice a day to apparent satiation for 10 weeks. The results showed that dietary Pro and Hyp supplementation had no significant effect on growth performance and feed utilization of juvenile turbot (P > 0.05). Total Hyp and collagen concentrations in muscle were significantly increased when dietary Pro and Hyp increased (P <0.05), and fish fed diet Pro+Hyp showed significantly higher free Hyp content in plasma than those fed other diets (P <0.05). The expression of P4H a(I) gene in liver and muscle was significantly up regulated in fish fed diet Pro-0.75 in comparison with control (P <0.05); however the gene was significantly down regulated in fish fed diet Pro+Hyp in muscle in comparison with fish fed diet Pro-0.75 (P <0.05). It can be concluded that supplement of crystal L-Pro and L-Hyp to high plant protein diets did not show positive effects on growth performance of juvenile turbot, but enhanced total collagen concentrations in muscle.

  19. Effects of food ration on SMR: influence of food consumption on individual variation in metabolic rate in juvenile coho salmon (Onchorhynchus kisutch).

    PubMed

    Van Leeuwen, Travis E; Rosenfeld, Jordan S; Richards, Jeffrey G

    2012-03-01

    1. Consistency of differences in standard metabolic rate (SMR) between individual juvenile salmonids and the apparently limited ability of individuals to regulate their SMR has led many researchers to conclude that differences in individual SMR are fixed (i.e. genetic). 2. To test for the effects of food ration on individual performance and metabolism, SMR was estimated by measuring oxygen consumption using flow-through respirometry on individually separated young of the year coho salmon (Oncorhynchus kisutch) placed on varying food rations over a period of 44 days. 3. Results demonstrate that the quantity of food consumed directly affects SMR of juvenile coho salmon, independent of specific dynamic action (SDA, an elevation in metabolic rate from the increased energy demands associated with digestion immediately following a meal) and indicates that higher food consumption is a cause of elevated SMR rather than a consequence of it. Juvenile coho salmon therefore demonstrated an ability to regulate their SMR according to food availability and ultimately food consumption. 4. This study indicates that food consumption may play a pivotal role in understanding individual variation in SMR independent of inherent genetic differences. We suggest that studies involving SMR need to be cautious about the effects of intra-individual differences in food consumption in communal tanks or in different microhabitats in the wild as disproportionate food consumption may contribute more to variation in SMR than intrinsic (genetic) factors. 5. In general, our results suggest that evolutionary changes in SMR are likely a response to selection on food consumption and growth, rather than SMR itself.

  20. The influence of growth hormone (GH) deficiency and GH replacement on quality of life in GH-deficient patients.

    PubMed

    Deijen, J B; van der Veen, E A

    1999-01-01

    The total absence of hormones such as cortisol or thyroxine causes death within weeks. Lack of estrogen or testosterone is followed by infertility and impaired sexual functioning. Relative deficiencies of almost all classical hormones have a substantial impact on quality of life (QOL). However, in contrast to virtually all aspects of metabolism, QOL is difficult to measure. Only recently have tests been developed to assess general QOL, whereas specific tests address those aspects of QOL affected only in specific situations or disease states. For example, in rheumatoid arthritis and other chronic disabling diseases, the use of measures of QOL to assess treatment modalities is almost routine. In diseases with overt metabolic disturbances attention is generally focused on changes in metabolic parameters and the issue of QOL is neglected. Although very few practising endocrinologists will not support the idea that they specialize in improving QOL, its assessment in patients with endocrinological disorders began only recently--in patients with growth hormone (GH) deficiency only 10 years ago. It became apparent that GH deficiency in adult life is unmistakably followed by changes in parameters that determine QOL. In adults with childhood-onset GH deficiency, the unemployment rate is higher and the marriage rate lower than in the general population. Another symbol of success in life, the possession of a driver's licence, is less frequently attained by these patients. Most patients with adult-onset GH deficiency score unfavourably in questionnaires such as the Nottingham Health Profile. GH substitution is now available on a scale large enough to enable studies to be made of the effects on QOL in adults. The first studies were reported in 1989. However, only in the last few years have studies appeared in which sufficient number of patients and sufficient length of treatment were reported to allow a more objective judgement of the effectiveness of GH substitution. Although

  1. Influence of Mg2+ on detection of somatogenic and lactogenic components of growth-hormone-binding protein in mammalian sera.

    PubMed Central

    Amit, T; Hochberg, Z; Barkey, R J

    1993-01-01

    We recently classified the growth-hormone (GH)-binding protein (GH-BP) in a wide range of mammalian [including human (h)] sera and reported the existence of a major lactogenic component in GH-BP of type-III sera (rabbit, horse, dog, pig and cat), based on the capacity of bovine (b) and ovine prolactin (PRL) to displace 125I-labelled human growth hormone (hGH) binding and on direct 125I-bPRL binding studies. In this study, we demonstrate the high degree of Mg2+ dependence of the binding of the classically lactogenic hGH and bPRL, but not that of the somatogenic bGH to various mammalian sera (types I-IV). Serum GH-BP was assayed using a previously described and validated charcoal-separation assay. 125I-hGH binding to rat, ovine, bovine, rabbit, horse, dog and human sera was enhanced 1.5-2.5-fold in the presence of 70 mM Mg2+. The Mg2+ effect was concentration-dependent between 3.7 mM and 70 mM, causing a significant and proportional increase in 125I-hGH binding to serum. Like 125I-hGH, 125I-bPRL binding to type-III sera was also Mg(2+)-dependent. In contrast, 125I-bGH binding to all types of serum GH-BP was not affected by Mg2+ concentrations of up to 35 mM, while 70 mM Mg2+ slightly, but significantly, reduced (by approx. 15%) bGH binding to rabbit serum. In keeping with the Mg(2+)-dependent stimulation of lactogenic hormone binding to GH-BP, 70 mM Mg2+ caused a shift to the left in the displacement curves of hGH and bPRL competing with 125I-hGH binding to rabbit, dog, horse and human sera, while the effects of the somatogens bGH and rabbit GH were shifted to the right. Scatchard analysis of hGH displacement curves with sera from various species yielded linear plots and revealed that Mg2+ significantly increased (2.3-3.0-fold) the affinity constants, but not the binding capacities. These results demonstrate the ability of changes in Mg2+ concentration to determine the degree of differential recognition of somatogens versus lactogens by serum GH-BP. It remains to be

  2. Wild jackdaws' reproductive success and their offspring's stress hormones are connected to provisioning rate and brood size, not to parental neophobia.

    PubMed

    Greggor, Alison L; Spencer, Karen A; Clayton, Nicola S; Thornton, Alex

    2017-03-01

    Many species show individual variation in neophobia and stress hormones, but the causes and consequences of this variation in the wild are unclear. Variation in neophobia levels could affect the number of offspring animals produce, and more subtly influence the rearing environment and offspring development. Nutritional deficits during development can elevate levels of stress hormones that trigger long-term effects on learning, memory, and survival. Therefore measuring offspring stress hormone levels, such as corticosterone (CORT), helps determine if parental neophobia influences the condition and developmental trajectory of young. As a highly neophobic species, jackdaws (Corvus monedula) are excellent for exploring the potential effects of parental neophobia on developing offspring. We investigated if neophobic responses, alongside known drivers of fitness, influence nest success and offspring <