66 research outputs found

    Functional Conservation of Cis-Regulatory Elements of Heat-Shock Genes over Long Evolutionary Distances

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    Transcriptional control of gene regulation is an intricate process that requires precise orchestration of a number of molecular components. Studying its evolution can serve as a useful model for understanding how complex molecular machines evolve. One way to investigate evolution of transcriptional regulation is to test the functions of cis-elements from one species in a distant relative. Previous results suggested that few, if any, tissue-specific promoters from Drosophila are faithfully expressed in C. elegans. Here we show that, in contrast, promoters of fly and human heat-shock genes are upregulated in C. elegans upon exposure to heat. Inducibility under conditions of heat shock may represent a relatively simple “on-off” response, whereas complex expression patterns require integration of multiple signals. Our results suggest that simpler aspects of regulatory logic may be retained over longer periods of evolutionary time, while more complex ones may be diverging more rapidly

    The United States of America and Scientific Research

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    To gauge the current commitment to scientific research in the United States of America (US), we compared federal research funding (FRF) with the US gross domestic product (GDP) and industry research spending during the past six decades. In order to address the recent globalization of scientific research, we also focused on four key indicators of research activities: research and development (R&D) funding, total science and engineering doctoral degrees, patents, and scientific publications. We compared these indicators across three major population and economic regions: the US, the European Union (EU) and the People's Republic of China (China) over the past decade. We discovered a number of interesting trends with direct relevance for science policy. The level of US FRF has varied between 0.2% and 0.6% of the GDP during the last six decades. Since the 1960s, the US FRF contribution has fallen from twice that of industrial research funding to roughly equal. Also, in the last two decades, the portion of the US government R&D spending devoted to research has increased. Although well below the US and the EU in overall funding, the current growth rate for R&D funding in China greatly exceeds that of both. Finally, the EU currently produces more science and engineering doctoral graduates and scientific publications than the US in absolute terms, but not per capita. This study's aim is to facilitate a serious discussion of key questions by the research community and federal policy makers. In particular, our results raise two questions with respect to: a) the increasing globalization of science: “What role is the US playing now, and what role will it play in the future of international science?”; and b) the ability to produce beneficial innovations for society: “How will the US continue to foster its strengths?

    The Origins of Novel Protein Interactions during Animal Opsin Evolution

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    Background. Biologists are gaining an increased understanding of the genetic bases of phenotypic change during evolution. Nevertheless, the origins of phenotypes mediated by novel protein-protein interactions remain largely undocumented. Methodology/Principle Findings. Here we analyze the evolution of opsin visual pigment proteins from the genomes of early branching animals, including a new class of opsins from Cnidaria. We combine these data with existing knowledge of the molecular basis of opsin function in a rigorous phylogenetic framework. We identify adaptive amino acid substitutions in duplicated opsin genes that correlate with a diversification of physiological pathways mediated by different protein-protein interactions. Conclusions/Significance. This study documents how gene duplication events early in the history of animals followed by adaptive structural mutations increased organismal complexity by adding novel protein-protein interactions that underlie different physiological pathways. These pathways are central to vision and other photo-reactive phenotypes in most extant animals. Similar evolutionary processes may have been a work in generating other metazoan sensory systems and other physiological processes mediated by signal transduction

    FoxO and Stress Responses in the Cnidarian Hydra vulgaris

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    Background: In the face of changing environmental conditions, the mechanisms underlying stress responses in diverse organisms are of increasing interest. In vertebrates, Drosophila, and Caenorhabditis elegans, FoxO transcription factors mediate cellular responses to stress, including oxidative stress and dietary restriction. Although FoxO genes have been identified in early-arising animal lineages including sponges and cnidarians, little is known about their roles in these organisms. Methods/Principal Findings: We have examined the regulation of FoxO activity in members of the well-studied cnidarian genus Hydra. We find that Hydra FoxO is expressed at high levels in cells of the interstitial lineage, a cell lineage that includes multipotent stem cells that give rise to neurons, stinging cells, secretory cells and gametes. Using transgenic Hydra that express a FoxO-GFP fusion protein in cells of the interstitial lineage, we have determined that heat shock causes localization of the fusion protein to the nucleus. Our results also provide evidence that, as in bilaterian animals, Hydra FoxO activity is regulated by both Akt and JNK kinases. Conclusions: These findings imply that basic mechanisms of FoxO regulation arose before the evolution of bilaterians an

    The lack of evidence behind over-the-counter antioxidant supplements for male fertility patients: a scoping review.

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    STUDY QUESTION: What is the evidence for over-the-counter antioxidant supplements for male infertility? SUMMARY ANSWER: Less than half of over-the-counter antioxidant supplements for male fertility patients have been tested in a clinical trial, and the available clinical trials are generally of poor quality. WHAT IS KNOWN ALREADY: The prevalence of male infertility is rising and, with this, the market for supplements claiming to improve male fertility is expanding. Up to now, there is limited data on the evidence for these over-the-counter supplements. STUDY DESIGN SIZE DURATION: Amazon, Google Shopping and other relevant shopping websites were searched on 24 June 2022 with the following terms: 'supplements', 'antioxidants', 'vitamins', AND 'male fertility', 'male infertility', 'male subfertility', 'fertility men', 'fertility man'. All supplements with a description of ingredients in English, Dutch, French, Spanish, or German were included. Subsequently, Pubmed and Google Scholar were searched for studies that included the supplements. PARTICIPANTS/MATERIALS SETTING METHODS: Inclusion criteria were supplements with antioxidant properties, of which the main purpose was to improve male fertility. Included supplements must be available without a doctor's prescription. Supplements containing plant extracts were excluded, as well as supplements of which the content or dosage was not clear. The ingredients, dosage, price and health claims of the supplements were recorded. We assessed whether substances in the supplements exceeded the recommended dietary allowance (RDA) or tolerable upper intake level (UL). All clinical trials and animal studies investigating included supplements were selected for this review. Clinical trials were assessed for risk of bias with a risk of bias tool appropriate for the study design. MAIN RESULTS AND THE ROLE OF CHANCE: There were 34 eligible antioxidant supplements found, containing 48 different active substances. The average price per 30 days was 53.10 US dollars. Most of the supplements (27/34, 79%) contained substances in a dosage exceeding the recommended daily allowance (RDA). All manufacturers of the supplements made health claims related to the improvement of sperm quality or male fertility. For 13 of the 34 supplements (38%), published clinical trials were available, and for one supplement, only an animal study was found. The overall quality of the included studies was poor. Only two supplements were tested in a good quality clinical trial. LIMITATIONS REASONS FOR CAUTION: As a consequence of searching shopping websites, a comprehensive search strategy could not be formulated. Most supplements were excluded because they contained plant extracts or because supplement information was not available (in an appropriate language). WIDER IMPLICATIONS OF THE FINDINGS: This is the first review that gives an insight into the market of male fertility supplements as available to infertility patients and other men seeking to improve their fertility. Earlier reviews have focused only on supplements with published clinical trials. However, we show that more than half of the supplements have not been tested in a clinical trial. To our knowledge, this review is the first to assess the dosage of supplements in relation to the RDA. In agreement with the literature, we found that the evidence on male fertility supplements is generally of poor quality. This review should urge pharmaceutical companies to evaluate their products in randomized controlled trials in order to provide people with substantiated information. STUDY FUNDING/COMPETING INTERESTS: The research position of W.R.d.L. is funded by an unrestricted grant from Goodlife Pharma. W.R.d.L., K.F., and J.P.d.B. are in the research team of a clinical trial on Impryl(®), one of the supplements included in this review. REGISTRATION NUMBER: N/A
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