The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Jozef Vanden Broeck - One of the best experts on this subject based on the ideXlab platform.
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The ecdysone receptor complex is essential for the Reproductive success in the Female desert locust, Schistocerca gregaria
Scientific Reports, 2019Co-Authors: Cynthia Lenaerts, Elisabeth Marchal, Paulien Peeters, Jozef Vanden BroeckAbstract:Ecdysteroid hormones influence the development and reproduction of arthropods by binding a heterodimeric complex of nuclear receptors, the ecdysone receptor (EcR) and the retinoid-X-receptor/ultraspiracle (RXR/USP). Here, we report on the in vivo role(s) of the ecdysone receptor complex, SchgrEcR/SchgrRXR , in the Female Reproductive Physiology of a major phytophagous pest insect, i.e. the desert locust, Schistocerca gregaria . Tissue and temporal distribution profiles were analysed during the first gonadotrophic cycle of adult Female locusts. RNA interference was used as a reverse genetics tool to investigate the in vivo role of the ecdysone receptor complex in ovarian maturation, oogenesis, fertility and fecundity. We discovered that silencing the ecdysone receptor complex in S. gregaria resulted in impaired ovulation and oviposition, indicative for a crucial role of this complex in chorion formation. We also found evidence for a feedback of SchgrEcR/SchgrRXR on juvenile hormone biosynthesis by the corpora allata. Furthermore, we observed a tissue-dependent effect of the SchgrEcR/SchgrRXR knockdown on the transcript levels of the insulin receptor and neuroparsin 3 and 4. The insulin receptor transcript levels were upregulated in the brain, but not the fat body and gonads. Neuroparsins 3 and 4 transcript levels were down regulated in the brain and fat body, but not in the gonads.
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Role of the venus kinase receptor in the Female Reproductive Physiology of the desert locust, Schistocerca gregaria
Scientific Reports, 2017Co-Authors: Cynthia Lenaerts, Jolien Palmans, Elisabeth Marchal, Rik Verdonck, Jozef Vanden BroeckAbstract:Venus kinase receptors (VKR) are a subfamily of invertebrate receptor tyrosine kinases, which have only recently been discovered. They contain an intracellular tyrosine kinase domain and an extracellular Venus FlyTrap domain. VKRs have been functionally and pharmacologically characterized in only two invertebrate species, namely the human parasite Schistosoma mansoni and the mosquito Aedes aegypti , where they play a crucial role in oogenesis. Here, we report the characterization of a VKR in the desert locust, Schistocerca gregaria . We performed an in-depth profiling study of the SgVKR transcript levels in different tissues throughout the Female adult stage. Using the RNA interference technique, the possible role of SgVKR was investigated. SgVKR knockdown had significant effects on ovarian ecdysteroid levels and on the size of oocytes during the vitellogenic stage. Sg VKR is probably involved in the complex cross-talk between several important pathways regulating Female Reproductive Physiology. Contrary to A. aegypti and S. mansoni , we cannot conclude that this receptor is essential for reproduction, since silencing SgVKR did not affect fecundity or fertility. Considering the evolutionary distance between A. aegypti and S. gregaria , as well as the differences in regulation of their Female Reproductive Physiology, this article constitutes a valuable asset in better understanding VKRs.
Anne M. Etgen - One of the best experts on this subject based on the ideXlab platform.
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mechanisms of ovarian steroid regulation of norepinephrine receptor mediated signal transduction in the hypothalamus implications for Female Reproductive Physiology
Hormones and Behavior, 2001Co-Authors: Anne M. Etgen, Michael A Ansonoff, Arnulfo QuesadaAbstract:Abstract In many mammalian species, the ovarian steroid hormones estradiol (E 2 ) and progesterone (P) act in the hypothalamus and preoptic area to coordinate the timing of Female sexual receptivity with ovulation. We study lordosis behavior, an important component of sexual receptivity in rats, and its regulation by E 2 and P as a model system for understanding how hormonal modulation of synaptic neurotransmission influences Reproductive Physiology and behavior. Our findings suggest that E 2 and P extensively regulate synaptic communication involving the catecholamine norepinephrine (NE) in the hypothalamus. Estrogen priming shifts the balance of postsynaptic NE receptor signaling in the hypothalamus and preoptic area away from β-adrenergic activation of cAMP synthesis toward α 1 -adrenergic signaling pathways. Attenuation of β-adrenergic signal transduction is achieved by receptor–G-protein uncoupling, apparently due to stable receptor phosphorylation. E 2 modification of α 1 -adrenergic signaling includes both increased expression of the α 1B -adrenoceptor subtype and a dramatic, P-induced reconfiguration of the biochemical responses initiated by agonist activation of α 1 -adrenoceptors. Among these is the emergence of α 1 -adrenergic receptor coupling to cGMP synthesis. We also present evidence that estrogen promotes novel, functional interactions between insulin-like growth factor-1 (IGF-1) and α 1 -adrenergic receptor signaling in the hypothalamus and preoptic area. Thus, estrogen amplification of signaling mediated by α 1 -adrenoceptors is multifaceted, involving changes in gene expression (of the α 1B -adrenoceptor), switching of receptor linkage to previously inactive intracellular pathways, and the promotion of cross talk between IGF-1 and NE receptors. We propose that this hormone-dependent remodeling of hypothalamic responses to NE maximizes Reproductive success by coordinating the timing of the preovulatory release of gonadotropins with the period of behavioral receptivity in Female rodents.
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Estradiol elevates protein kinase C catalytic activity in the preoptic area of Female rats.
Endocrinology, 1998Co-Authors: Michael A Ansonoff, Anne M. EtgenAbstract:Estrogen acts in the brain to regulate Female Reproductive Physiology and behavior, and protein kinase C (PKC) is estrogen-regulated in many estrogen-responsive tissues. We examined whether estrogen regulates PKC in the hypothalamus (HYP) and preoptic area (POA), brain regions which mediate estrogenic control of Female Reproductive function. PKC activity in tissue from hormone-treated and control Female rats was measured, in the presence of phorbol ester and calcium, by quantifying 32P incorporation into a substrate peptide. PKC catalytic activity increased significantly in POA tissue extracts from estradiol-treated, ovariectomized (OVX) Female rats but not in HYP or cortical extracts. Phorbol ester potentiation of cAMP accumulation also was examined to determine whether the ability of PKC to potentiate adenylyl cyclase activity was affected by estrogen. PKC stimulation potentiated forskolin-induced cAMP accumulation to a greater degree in POA, but not HYP, slices from estrogen-treated OVX Female rats. PK...
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Ovarian steroids increase veratridine-induced release of amino acid neurotransmitters in preoptic area synaptosomes.
Brain Research, 1990Co-Authors: Amos Fleischmann, Maynard H. Makman, Anne M. EtgenAbstract:Abstract In vivo treatment of ovariectomized rats with estradiol benzoate plus progesterone, but not with either steroid alone, produced a large increase in veratridine-induced release of radiolabeled glutamate and newly synthesized GABA from preoptic area synaptosomes in vitro. Neither basal nor KCl-evoked release of amino acids was altered. Thus gonadal steroids appear to be involved in the control of amino acid neurotransmitter release in a brain region of importance for regulation of Female Reproductive Physiology and behavior.
Cynthia Lenaerts - One of the best experts on this subject based on the ideXlab platform.
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The ecdysone receptor complex is essential for the Reproductive success in the Female desert locust, Schistocerca gregaria
Scientific Reports, 2019Co-Authors: Cynthia Lenaerts, Elisabeth Marchal, Paulien Peeters, Jozef Vanden BroeckAbstract:Ecdysteroid hormones influence the development and reproduction of arthropods by binding a heterodimeric complex of nuclear receptors, the ecdysone receptor (EcR) and the retinoid-X-receptor/ultraspiracle (RXR/USP). Here, we report on the in vivo role(s) of the ecdysone receptor complex, SchgrEcR/SchgrRXR , in the Female Reproductive Physiology of a major phytophagous pest insect, i.e. the desert locust, Schistocerca gregaria . Tissue and temporal distribution profiles were analysed during the first gonadotrophic cycle of adult Female locusts. RNA interference was used as a reverse genetics tool to investigate the in vivo role of the ecdysone receptor complex in ovarian maturation, oogenesis, fertility and fecundity. We discovered that silencing the ecdysone receptor complex in S. gregaria resulted in impaired ovulation and oviposition, indicative for a crucial role of this complex in chorion formation. We also found evidence for a feedback of SchgrEcR/SchgrRXR on juvenile hormone biosynthesis by the corpora allata. Furthermore, we observed a tissue-dependent effect of the SchgrEcR/SchgrRXR knockdown on the transcript levels of the insulin receptor and neuroparsin 3 and 4. The insulin receptor transcript levels were upregulated in the brain, but not the fat body and gonads. Neuroparsins 3 and 4 transcript levels were down regulated in the brain and fat body, but not in the gonads.
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Role of the venus kinase receptor in the Female Reproductive Physiology of the desert locust, Schistocerca gregaria
Scientific Reports, 2017Co-Authors: Cynthia Lenaerts, Jolien Palmans, Elisabeth Marchal, Rik Verdonck, Jozef Vanden BroeckAbstract:Venus kinase receptors (VKR) are a subfamily of invertebrate receptor tyrosine kinases, which have only recently been discovered. They contain an intracellular tyrosine kinase domain and an extracellular Venus FlyTrap domain. VKRs have been functionally and pharmacologically characterized in only two invertebrate species, namely the human parasite Schistosoma mansoni and the mosquito Aedes aegypti , where they play a crucial role in oogenesis. Here, we report the characterization of a VKR in the desert locust, Schistocerca gregaria . We performed an in-depth profiling study of the SgVKR transcript levels in different tissues throughout the Female adult stage. Using the RNA interference technique, the possible role of SgVKR was investigated. SgVKR knockdown had significant effects on ovarian ecdysteroid levels and on the size of oocytes during the vitellogenic stage. Sg VKR is probably involved in the complex cross-talk between several important pathways regulating Female Reproductive Physiology. Contrary to A. aegypti and S. mansoni , we cannot conclude that this receptor is essential for reproduction, since silencing SgVKR did not affect fecundity or fertility. Considering the evolutionary distance between A. aegypti and S. gregaria , as well as the differences in regulation of their Female Reproductive Physiology, this article constitutes a valuable asset in better understanding VKRs.
Patricia J Moore - One of the best experts on this subject based on the ideXlab platform.
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sexual conflict and the evolution of Female mate choice and male social dominance
Proceedings of The Royal Society B: Biological Sciences, 2001Co-Authors: Allen J Moore, W G Wallin, Patricia Adair Gowaty, Patricia J MooreAbstract:Conflicts between the sexes over control of reproduction are thought to lead to a cost of sexual selection through the evolution of male traits that manipulate Female Reproductive Physiology and behaviour, and Female traits that resist this manipulation. Although studies have begun to document negative fitness effects of sexual conflict, studies showing the expected association between sexual conflict and the specific behavioural mechanisms of sexual selection are lacking. Here we experimentally manipulated the opportunity for sexual conflict in the cockroach Nauphoeta cinerea and showed that, for this species, odour cues in the social environment influence the behavioural strategies and fitness of males and Females during sexual selection. Females provided with the opportunity for discriminating between males but not necessarily mating with preferred males produced fewer male offspring than Females mated at random. The number of Female offspring produced was not affected, nor was the viability of the offspring. Experimental modification of the composition of the males9 pheromone showed that the fecundity effects were caused by exposure to the pheromone component that makes males attractive to Females but also makes males less likely to be dominant. Female mate choice therefore carries a demographic cost but functions to avoid male manipulation and aggression. Male–male competition appears to function to circumvent mate choice rather than directly manipulating Females, as the mate choice can be cryptic. The dynamic struggle between the sexes for control of mating opportunities and outcomes in N.cinerea therefore reveals a unique role for sexual conflict in the evolution of the behavioural components of sexual selection.
Arnulfo Quesada - One of the best experts on this subject based on the ideXlab platform.
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mechanisms of ovarian steroid regulation of norepinephrine receptor mediated signal transduction in the hypothalamus implications for Female Reproductive Physiology
Hormones and Behavior, 2001Co-Authors: Anne M. Etgen, Michael A Ansonoff, Arnulfo QuesadaAbstract:Abstract In many mammalian species, the ovarian steroid hormones estradiol (E 2 ) and progesterone (P) act in the hypothalamus and preoptic area to coordinate the timing of Female sexual receptivity with ovulation. We study lordosis behavior, an important component of sexual receptivity in rats, and its regulation by E 2 and P as a model system for understanding how hormonal modulation of synaptic neurotransmission influences Reproductive Physiology and behavior. Our findings suggest that E 2 and P extensively regulate synaptic communication involving the catecholamine norepinephrine (NE) in the hypothalamus. Estrogen priming shifts the balance of postsynaptic NE receptor signaling in the hypothalamus and preoptic area away from β-adrenergic activation of cAMP synthesis toward α 1 -adrenergic signaling pathways. Attenuation of β-adrenergic signal transduction is achieved by receptor–G-protein uncoupling, apparently due to stable receptor phosphorylation. E 2 modification of α 1 -adrenergic signaling includes both increased expression of the α 1B -adrenoceptor subtype and a dramatic, P-induced reconfiguration of the biochemical responses initiated by agonist activation of α 1 -adrenoceptors. Among these is the emergence of α 1 -adrenergic receptor coupling to cGMP synthesis. We also present evidence that estrogen promotes novel, functional interactions between insulin-like growth factor-1 (IGF-1) and α 1 -adrenergic receptor signaling in the hypothalamus and preoptic area. Thus, estrogen amplification of signaling mediated by α 1 -adrenoceptors is multifaceted, involving changes in gene expression (of the α 1B -adrenoceptor), switching of receptor linkage to previously inactive intracellular pathways, and the promotion of cross talk between IGF-1 and NE receptors. We propose that this hormone-dependent remodeling of hypothalamic responses to NE maximizes Reproductive success by coordinating the timing of the preovulatory release of gonadotropins with the period of behavioral receptivity in Female rodents.
