659 research outputs found

    Assessing the Sensitivity of Different Life Stages for Sexual Disruption in Roach (Rutilus rutilus) Exposed to Effluents from Wastewater Treatment Works

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    Surveys of U.K. rivers have shown a high incidence of sexual disruption in populations of wild roach (Rutilus rutilus) living downstream from wastewater treatment works (WwTW), and the degree of intersex (gonads containing both male and female structural characteristics) has been correlated with the concentration of effluent in those rivers. In this study, we investigated feminized responses to two estrogenic WwTWs in roach exposed for periods during life stages of germ cell division (early life and the postspawning period). Roach were exposed as embryos from fertilization up to 300 days posthatch (dph; to include the period of gonadal sex differentiation) or as postspawning adult males, and including fish that had received previous estrogen exposure, for either 60 or 120 days when the annual event of germ cell proliferation occurs. Both effluents induced vitellogenin synthesis in both life stages studied, and the magnitude of the vitellogenic responses paralleled the effluent content of steroid estrogens. Feminization of the reproductive ducts occurred in male fish in a concentration-dependent manner when the exposure occurred during early life, but we found no effects on the reproductive ducts in adult males. Depuration studies (maintenance of fish in clean water after exposure to WwTW effluent) confirmed that the feminization of the reproductive duct was permanent. We found no evidence of ovotestis development in fish that had no previous estrogen exposure for any of the treatments. In wild adult roach that had previously received exposure to estrogen and were intersex, the degree of intersex increased during the study period, but this was not related to the immediate effluent exposure, suggesting a previously determined programming of ovotestis formation

    Assessing the exposure risk and impacts of pharmaceuticals in the environment on individuals and ecosystems.

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    The use of human and veterinary pharmaceuticals is increasing. Over the past decade, there has been a proliferation of research into potential environmental impacts of pharmaceuticals in the environment. A Royal Society-supported seminar brought together experts from diverse scientific fields to discuss the risks posed by pharmaceuticals to wildlife. Recent analytical advances have revealed that pharmaceuticals are entering habitats via water, sewage, manure and animal carcases, and dispersing through food chains. Pharmaceuticals are designed to alter physiology at low doses and so can be particularly potent contaminants. The near extinction of Asian vultures following exposure to diclofenac is the key example where exposure to a pharmaceutical caused a population-level impact on non-target wildlife. However, more subtle changes to behaviour and physiology are rarely studied and poorly understood. Grand challenges for the future include developing more realistic exposure assessments for wildlife, assessing the impacts of mixtures of pharmaceuticals in combination with other environmental stressors and estimating the risks from pharmaceutical manufacturing and usage in developing countries. We concluded that an integration of diverse approaches is required to predict 'unexpected' risks; specifically, ecologically relevant, often long-term and non-lethal, consequences of pharmaceuticals in the environment for wildlife and ecosystems

    Do contaminants originating from state-of-the-art treated wastewater impact the ecological quality of surface waters?

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    Since the 1980s, advances in wastewater treatment technology have led to considerably improved surface water quality in the urban areas of many high income countries. However, trace concentrations of organic wastewater-associated contaminants may still pose a key environmental hazard impairing the ecological quality of surface waters. To identify key impact factors, we analyzed the effects of a wide range of anthropogenic and environmental variables on the aquatic macroinvertebrate community. We assessed ecological water quality at 26 sampling sites in four urban German lowland river systems with a 0–100% load of state-of-the-art biological activated sludge treated wastewater. The chemical analysis suite comprised 12 organic contaminants (five phosphor organic flame retardants, two musk fragrances, bisphenol A, nonylphenol, octylphenol, diethyltoluamide, terbutryn), 16 polycyclic aromatic hydrocarbons, and 12 heavy metals. Non-metric multidimensional scaling identified organic contaminants that are mainly wastewater-associated (i.e., phosphor organic flame retardants, musk fragrances, and diethyltoluamide) as a major impact variable on macroinvertebrate species composition. The structural degradation of streams was also identified as a significant factor. Multiple linear regression models revealed a significant impact of organic contaminants on invertebrate populations, in particular on Ephemeroptera, Plecoptera, and Trichoptera species. Spearman rank correlation analyses confirmed wastewater-associated organic contaminants as the most significant variable negatively impacting the biodiversity of sensitive macroinvertebrate species. In addition to increased aquatic pollution with organic contaminants, a greater wastewater fraction was accompanied by a slight decrease in oxygen concentration and an increase in salinity. This study highlights the importance of reducing the wastewater-associated impact on surface waters. For aquatic ecosystems in urban areas this would lead to: (i) improvement of the ecological integrity, (ii) reduction of biodiversity loss, and (iii) faster achievement of objectives of legislative requirements, e.g., the European Water Framework Directive

    Ethnicity and Population Structure in Personal Naming Networks

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    Personal naming practices exist in all human groups and are far from random. Rather, they continue to reflect social norms and ethno-cultural customs that have developed over generations. As a consequence, contemporary name frequency distributions retain distinct geographic, social and ethno-cultural patterning that can be exploited to understand population structure in human biology, public health and social science. Previous attempts to detect and delineate such structure in large populations have entailed extensive empirical analysis of naming conventions in different parts of the world without seeking any general or automated methods of population classification by ethno-cultural origin. Here we show how 'naming networks', constructed from forename-surname pairs of a large sample of the contemporary human population in 17 countries, provide a valuable representation of cultural, ethnic and linguistic population structure around the world. This innovative approach enriches and adds value to automated population classification through conventional national data sources such as telephone directories and electoral registers. The method identifies clear social and ethno-cultural clusters in such naming networks that extend far beyond the geographic areas in which particular names originated, and that are preserved even after international migration. Moreover, one of the most striking findings of this approach is that these clusters simply 'emerge' from the aggregation of millions of individual decisions on parental naming practices for their children, without any prior knowledge introduced by the researcher. Our probabilistic approach to community assignment, both at city level as well as at a global scale, helps to reveal the degree of isolation, integration or overlap between human populations in our rapidly globalising world. As such, this work has important implications for research in population genetics, public health, and social science adding new understandings of migration, identity, integration and social interaction across the world

    Haplotype block structure study of the CFTR gene. Most variants are associated with the M470 allele in several European populations

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    An average of about 1700 CFTR (cystic fibrosis transmembrane conductance regulator) alleles from normal individuals from different European populations were extensively screened for DNA sequence variation. A total of 80 variants were observed: 61 coding SNSs (results already published), 13 noncoding SNSs, three STRs, two short deletions, and one nucleotide insertion. Eight DNA variants were classified as non-CF causing due to their high frequency of occurrence. Through this survey the CFTR has become the most exhaustively studied gene for its coding sequence variability and, though to a lesser extent, for its noncoding sequence variability as well. Interestingly, most variation was associated with the M470 allele, while the V470 allele showed an 'extended haplotype homozygosity' (EHH). These findings make us suggest a role for selection acting either on the M470V itself or through an hitchhiking mechanism involving a second site. The possible ancient origin of the V allele in an 'out of Africa' time frame is discussed

    NF90 Binds the Dengue Virus RNA 3′ Terminus and is a Positive Regulator of Dengue Virus Replication

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    Background Viral RNA translation and replication are regulated by sequence and structural elements in the 5′ and 3′ untranslated regions (UTR) and by host cell and/or viral proteins that bind them. Dengue virus has a single-stranded RNA genome with positive polarity, a 5′ m7GpppG cap, and a conserved 3′-terminal stem loop (SL) that is linked to proposed functions in viral RNA transcription and translation. Mechanisms explaining the contributions of host proteins to viral RNA translation and replication are poorly defined, yet understanding host protein-viral RNA interactions may identify new targets for therapeutic intervention. This study was directed at identifying functionally significant host proteins that bind the conserved dengue virus RNA 3′ terminus. Methodology/Principal Findings Proteins eluted from a dengue 3′ SL RNA affinity column at increasing ionic strength included two with double-strand RNA binding motifs (NF90/DRBP76 and DEAH box polypeptide 9/RNA helicase A (RHA)), in addition to NF45, which forms a heterodimer with NF90. Although detectable NF90 and RHA proteins localized to the nucleus of uninfected cells, immunofluorescence revealed cytoplasmic NF90 in dengue virus-infected cells, leading us to hypothesize that NF90 has a functional role(s) in dengue infections. Cells depleted of NF90 were used to quantify viral RNA transcript levels and production of infectious dengue virus. NF90 depletion was accompanied by a 50%-70% decrease in dengue RNA levels and in production of infectious viral progeny. Conclusions/Significance The results indicate that NF90 interacts with the 3′ SL structure of the dengue RNA and is a positive regulator of dengue virus replication. NF90 depletion diminished the production of infectious dengue virus by more than 50%, which may have important significance for identifying therapeutic targets to limit a virus that threatens more than a billion people worldwide.Ruth L. Kirschstein National Research Service Award (NIH-NRSA GM64985)UNCF-Merck Postdoctoral FellowshipNational Institute of Allergy and Infectious Diseases (U.S.)Ellison Medical Foundatio

    Mutations in TOP3A Cause a Bloom Syndrome-like Disorder

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    Bloom syndrome, caused by biallelic mutations in BLM, is characterized by prenatal-onset growth deficiency, short stature, an erythematous photosensitive malar rash, and increased cancer predisposition. Diagnostically, a hallmark feature is the presence of increased sister chromatid exchanges (SCEs) on cytogenetic testing. Here, we describe biallelic mutations in TOP3A in ten individuals with prenatal-onset growth restriction and microcephaly. TOP3A encodes topoisomerase III alpha (TopIIIα), which binds to BLM as part of the BTRR complex, and promotes dissolution of double Holliday junctions arising during homologous recombination. We also identify a homozygous truncating variant in RMI1, which encodes another component of the BTRR complex, in two individuals with microcephalic dwarfism. The TOP3A mutations substantially reduce cellular levels of TopIIIα, and consequently subjects’ cells demonstrate elevated rates of SCE. Unresolved DNA recombination and/or replication intermediates persist into mitosis, leading to chromosome segregation defects and genome instability that most likely explain the growth restriction seen in these subjects and in Bloom syndrome. Clinical features of mitochondrial dysfunction are evident in several individuals with biallelic TOP3A mutations, consistent with the recently reported additional function of TopIIIα in mitochondrial DNA decatenation. In summary, our findings establish TOP3A mutations as an additional cause of prenatal-onset short stature with increased cytogenetic SCEs and implicate the decatenation activity of the BTRR complex in their pathogenesis

    Y-chromosome descent clusters and male differential reproductive success: young lineage expansions dominate Asian pastoral nomadic populations

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    International audienceHigh-frequency microsatellite haplotypes of the male-specific Y-chromosome can signal past episodes of high reproductive success of particular men and their patrilineal descendants. Previously, two examples of such successful Y-lineages have been described in Asia, both associated with Altaic-speaking pastoral nomadic societies, and putatively linked to dynasties descending, respectively, from Genghis Khan and Giocangga. Here we surveyed a total of 5321 Y-chromosomes from 127 Asian populations, including novel Y-SNP and microsatellite data on 461 Central Asian males, to ask whether additional lineage expansions could be identified. Based on the most frequent eight-microsatellite haplotypes, we objectively defined 11 descent clusters (DCs), each within a specific haplogroup, that represent likely past instances of high male reproductive success, including the two previously identified cases. Analysis of the geographical patterns and ages of these DCs and their associated cultural characteristics showed that the most successful lineages are found both among sedentary agriculturalists and pastoral nomads, and expanded between 2100 BCE and 1100 CE. However, those with recent origins in the historical period are almost exclusively found in Altaic-speaking pastoral nomadic populations, which may reflect a shift in political organisation in pastoralist economies and a greater ease of transmission of Y-chromosomes through time and space facilitated by the use of horses

    Interlaboratory comparison of four in vitro assays for assessing androgenic and antiandrogenic activity of environmental chemicals.

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    We evaluated and compared four in vitro assays to detect androgen agonists and antagonists in an international interlaboratory study. Laboratory 1 used a cell proliferation assay (assay 1) with human mammary carcinoma cells stably transfected with human androgen receptor. The other laboratories used reporter gene assays, two based on stably transfected human prostate carcinoma cells (assay 2) or human mammary carcinoma cells (assay 4), and the third based on transient transfection of Chinese hamster ovary cells (assay 3). Four laboratories received four coded compounds and two controls: two steroidal androgens, two antiandrogens, an androgenic control, 5alpha-dihydrotestosterone (DHT), and an antiandrogenic control, bicalutamide (ICI 176,334). All laboratories correctly detected the androgenic activity of 4-androsten-3,17-dione and 17alpha-methyltestosterone. For both compounds, the calculated androgenic potencies relative to the positive control (RAPs) remained within one order of magnitude. However, laboratory 3 calculated a 50-fold higher RAP for 4-androsten-3,17-dione. All assays detected and quantified the antiandrogenic effect of vinclozolin [median inhibitory concentration (IC50) values ranging from 1.1 times symbol 10(-7) M to 4.7 times symbol 10(-7) M]. In assays 2 and 3, vinclozolin showed partial androgenic activity at the highest concentrations tested. For vinclozolin, calculated antiandrogenic potencies relative to bicalutamide (RAAPs) differed no more than a factor of 10, and IC50 values matched those of bicalutamide. Similarly, we found antiandrogenic activity for tris-(4-chlorophenyl)methanol. RAAP values were between 0.086 and 0.37. Three assays showed cytotoxicity for this compound at or above 1 times symbol 10(-5) M. In summary, all assays proved sensitive screening tools to detect and quantify androgen receptor-mediated androgenic and antiandrogenic effects of these chemicals accurately, with coefficients of variation between 8 and 90%

    Improved Resolution Haplogroup G Phylogeny in the Y Chromosome, Revealed by a Set of Newly Characterized SNPs

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    Background: Y-SNP haplogroup G (hgG), defined by Y-SNP marker M201, is relatively uncommon in the United States general population, with only 8 additional sub-markers characterized. Many of the previously described eight sub-markers are either very rare (2–4%) or do not distinguish between major populations within this hg. In fact, prior to the current study, only 2 % of our reference Caucasian population belonged to hgG and all of these individuals were in sub-haplogroup G2a, defined by P15. Additional Y-SNPs are needed in order to differentiate between individuals within this haplogroup. Principal Findings: In this work we have investigated whether we could differentiate between a population of 63 hgG individuals using previously uncharacterized Y-SNPs. We have designed assays to test these individuals using all known hgG SNPs (n = 9) and an additional 16 unreported/undefined Y-SNPS. Using a combination of DNA sequence and genetic genealogy databases, we have uncovered a total of 15 new hgG SNPs that had been previously reported but not phylogenetically characterized. Ten of the new Y-SNPs are phylogenetically equivalent to M201, one is equivalent to P15 and, interestingly, four create new, separate haplogroups. Three of the latter are more common than many of the previously defined Y-SNPs. Y-STR data from these individuals show that DYS385*12 is present in (70%) of G2a3b1-U13 individuals while only 4 % of non-G2a3b1-U13 individuals posses the DYS385*12 allele. Conclusions: This study uncovered several previously undefined Y-SNPs by using data from several database sources. Th
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