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1.
Swiss Med Wkly ; 153: 3441, 2023 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-37774383

RESUMO

AIM OF THE STUDY: Newly approved therapies with high and uncertain budget impact pose challenges to public health care systems worldwide. One recent example is chimeric antigen receptor T cell (CAR-T) therapies for adults with large B-cell lymphoma (LBCL). This study's primary objective is to examine the expenditures of Swiss public payers before, during, and after CAR-T cell therapy in patients with LBCL aged ≥30 years. Its secondary objective is to analyse 24-month survival rates. METHODS: This retrospective observational data analysis used the administrative databases of the Swiss health insurers Concordia, CSS, Groupe Mutuel, Helsana, ÖKK, Sanitas, SWICA, Sympany, and Visana. These health insurers or groups provide mandatory health insurance to approximately 78% of Swiss residents in 2021. Using the relevant procedure codes, we identified CAR-T therapies administered between October 2018 (first approval) and June 2021 (treatment identification cut-off). Patients aged <30 years were excluded because they might be treated for pediatric acute lymphoblastic leukaemia. Expenditures were categorised as pre-infusion, peri-infusion (excluding CAR-T therapy acquisition costs), and post-infusion based on the time of service provision. Overall survival rates were estimated using the Kaplan-Meier method. RESULTS: This study identified 81 patients aged ≥30 years, with a median follow-up period for censored observations of 27 months (interquartile range: 21-31 months). The median age group was 70-74, and 60% of patients were male. Mean healthcare expenditures per patient per month amounted to CHF 8,115-22,564 pre-infusion, CHF 38,490 peri-infusion, and CHF 5,068-11,342 post-infusion. For the total peri- and post-infusion period (i.e. 1-month before infusion to 23 months after infusion), mean healthcare expenditures amounted to CHF 215,737. The 24-month overall survival rate was 48% (95% confidence interval: 38-61%). CONCLUSIONS: Healthcare expenditures after CAR-T cell infusion are relatively high compared to previous estimates of patients with LBCL in the last year of treatment. Further research is needed to understand the drivers behind these post-infusion expenditures. Especially, clinical data should be used to assess the time until disease progression. The analysis of 24-month overall survival is consistent with results from the pivotal trials. Our findings stress the importance of post-approval studies to monitor real-world expenditures and outcomes related to innovative therapies.


Assuntos
Linfoma Difuso de Grandes Células B , Receptores de Antígenos Quiméricos , Adulto , Criança , Humanos , Masculino , Feminino , Gastos em Saúde , Estudos Retrospectivos , Suíça , Imunoterapia Adotiva , Seguro Saúde
2.
Cell Rep ; 42(1): 111961, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36640323

RESUMO

SPATA2 mediates the recruitment of CYLD to immune receptor complexes by bridging the interaction of CYLD with the linear ubiquitylation assembly complex (LUBAC) component HOIP. Whether SPATA2 exhibits functions independently of CYLD is unclear. Here, we show that, while Cyld-/- and Spata2-/- mice are viable, double mutants exhibit highly penetrant perinatal lethality, indicating independent functions of SPATA2 and CYLD. Cyld-/-Spata2-/- fibroblasts show increased M1-linked TNFR1-SC ubiquitylation and, similar to Cyld-/-Spata2-/- macrophages and intestinal epithelial cells, elevated pro-inflammatory gene expression compared with Cyld-/- or Spata2-/- cells. We show that SPATA2 competes with OTULIN for binding to HOIP via its PUB-interacting motif (PIM) and its zinc finger domain, thereby promoting autoubiquitylation of LUBAC. Consistently, increased pro-inflammatory signaling in Cyld-/-Spata2-/- cells depends on the presence of OTULIN. Our data therefore indicate that SPATA2 counteracts, independently of CYLD, the deubiquitylation of LUBAC by OTULIN and thereby attenuates LUBAC activity and pro-inflammatory signaling.


Assuntos
Transdução de Sinais , Fatores de Transcrição , Animais , Camundongos , Ubiquitinação , Fatores de Transcrição/metabolismo , NF-kappa B/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Enzima Desubiquitinante CYLD/metabolismo
3.
Cladistics ; 39(2): 129-143, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36576962

RESUMO

DNA sequence information has revealed many morphologically cryptic species worldwide. For animals, DNA-based assessments of species diversity usually rely on the mitochondrial cytochrome c oxidase subunit I (COI) gene. However, a growing amount of evidence indicate that mitochondrial markers alone can lead to misleading species diversity estimates due to mito-nuclear discordance. Therefore, reports of putative species based solely on mitochondrial DNA should be verified by other methods, especially in cases where COI sequences are identical for different morphospecies or where divergence within the same morphospecies is high. Freshwater amphipods are particularly interesting in this context because numerous putative cryptic species have been reported. Here, we investigated the species status of the numerous mitochondrial molecular operational taxonomic units (MOTUs) found within Echinogammarus sicilianus. We used an integrative approach combining DNA barcoding with mate selection observations, detailed morphometrics and genome-wide double digest restriction site-associated DNA sequencing (ddRAD-seq). Within a relatively small sampling area, we detected twelve COI MOTUs (divergence = 1.8-20.3%), co-occurring in syntopy at two-thirds of the investigated sites. We found that pair formation was random and there was extensive nuclear gene flow among the ten MOTUs co-occurring within the same river stretch. The four most common MOTUs were also indistinguishable with respect to functional morphology. Therefore, the evidence best fits the hypothesis of a single, yet genetically diverse, species within the main river system. The only two MOTUs sampled outside the focal area were genetically distinct at the nuclear level and may represent distinct species. Our study reveals that COI-based species delimitation can significantly overestimate species diversity, highlighting the importance of integrative taxonomy for species validation, especially in hyperdiverse complexes with syntopically occurring mitochondrial MOTUs.


Assuntos
Anfípodes , Código de Barras de DNA Taxonômico , Complexo IV da Cadeia de Transporte de Elétrons , Preferência de Acasalamento Animal , Animais , Anfípodes/genética , DNA Mitocondrial/genética , Água Doce , Polimorfismo de Nucleotídeo Único , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Preferência de Acasalamento Animal/fisiologia
4.
BMC Genomics ; 23(1): 816, 2022 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-36482300

RESUMO

BACKGROUND: Freshwaters are exposed to multiple anthropogenic stressors, leading to habitat degradation and biodiversity decline. In particular, agricultural stressors are known to result in decreased abundances and community shifts towards more tolerant taxa. However, the combined effects of stressors are difficult to predict as they can interact in complex ways, leading to enhanced (synergistic) or decreased (antagonistic) response patterns. Furthermore, stress responses may remain undetected if only the abundance changes in ecological experiments are considered, as organisms may have physiological protective pathways to counteract stressor effects. Therefore, we here used transcriptome-wide sequencing data to quantify single and combined effects of elevated fine sediment deposition, increased salinity and reduced flow velocity on the gene expression of the amphipod Gammarus fossarum in a mesocosm field experiment. RESULTS: Stressor exposure resulted in a strong transcriptional suppression of genes involved in metabolic and energy consuming cellular processes, indicating that G. fossarum responds to stressor exposure by directing energy to vitally essential processes. Treatments involving increased salinity induced by far the strongest transcriptional response, contrasting the observed abundance patterns where no effect was detected. Specifically, increased salinity induced the expression of detoxification enzymes and ion transporter genes, which control the membrane permeability of sodium, potassium or chloride. Stressor interactions at the physiological level were mainly antagonistic, such as the combined effect of increased fine sediment and reduced flow velocity. The compensation of the fine sediment induced effect by reduced flow velocity is in line with observations based on specimen abundance data. CONCLUSIONS: Our findings show that gene expression data provide new mechanistic insights in responses of freshwater organisms to multiple anthropogenic stressors. The assessment of stressor effects at the transcriptomic level and its integration with stressor effects at the level of specimen abundances significantly contribute to our understanding of multiple stressor effects in freshwater ecosystems.


Assuntos
Ecossistema
5.
Ecol Evol ; 12(4): e8807, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35432929

RESUMO

Water flow in river networks is frequently regulated by man-made in-stream barriers. These obstacles can hinder dispersal of aquatic organisms and isolate populations leading to the loss of genetic diversity. Although millions of small in-stream barriers exist worldwide, their impact on dispersal of macroinvertebrates remains unclear. Therefore, we, therefore, assessed the effects of such barriers on the population structure and effective dispersal of five macroinvertebrate species with strictly aquatic life cycles: the amphipod crustacean Gammarus fossarum (clade 11), three snail species of the Ancylus fluviatilis species complex and the flatworm Dugesia gonocephala. We studied populations at nine weirs and eight culverts (3 pipes, 5 tunnels), built 33-109 years ago, mainly in the heavily fragmented catchment of the river Ruhr (Sauerland, Germany). To assess fragmentation and barrier effects, we generated genome-wide SNP data using ddRAD sequencing and evaluated clustering, differentiation between populations up- and downstream of each barrier and effective migration rates among sites and across barriers. Additionally, we applied population genomic simulations to assess expected differentiation patterns under different gene flow scenarios. Our data show that populations of all species are highly isolated at regional and local scales within few kilometers. While the regional population structure likely results from historical processes, the strong local differentiation suggests that contemporary dispersal barriers exist. However, we identified significant barrier effects only for pipes (for A. fluviatilis II and III) and few larger weirs (>1.3 m; for D. gonocephala). Therefore, our data suggest that most small in-stream barriers can probably be overcome by all studied taxa frequently enough to prevent fragmentation. However, it remains to be tested if the strong local differentiation is a result of a cumulative effect of small barriers, or if larger in-stream barriers, land use, chemical pollution, urbanization, or a combination of these factors impede gene flow.

6.
Environ Microbiol ; 23(7): 3809-3824, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33559305

RESUMO

Ecological stability under environmental change is determined by both interspecific and intraspecific processes. Particularly for planktonic microorganisms, it is challenging to follow intraspecific dynamics over space and time. We propose a new method, microsatellite PoolSeq barcoding (MPB), for tracing allele frequency changes in protist populations. We successfully applied this method to experimental community incubations and field samples of the diatom Thalassiosira hyalina from the Arctic, a rapidly changing ecosystem. Validation of the method found compelling accuracy in comparison with established genotyping approaches within different diversity contexts. In experimental and environmental samples, we show that MPB can detect meaningful patterns of population dynamics, resolving allelic stability and shifts within a key diatom species in response to experimental treatments as well as different bloom phases and years. Through our novel MPB approach, we produced a large dataset of populations at different time-points and locations with comparably little effort. Results like this can add insights into the roles of selection and plasticity in natural protist populations under stable experimental but also variable field conditions. Especially for organisms where genotype sampling remains challenging, MPB holds great potential to efficiently resolve eco-evolutionary dynamics and to assess the mechanisms and limits of resilience to environmental stressors.


Assuntos
Diatomáceas , Regiões Árticas , Diatomáceas/genética , Ecossistema , Repetições de Microssatélites/genética , Dinâmica Populacional
7.
Zookeys ; 872: 57-68, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31496886

RESUMO

The larval stages of the central European sibling caddisfly species Sericostoma personatum (Spence in Kirby and Spence, 1826) and S. flavicorne Schneider, 1845 are morphologically similar and can only be distinguished by differences in coloration in late larval instars. Identification using the mitochondrial barcoding gene, i.e., the Cytochrome c Oxidase 1, is impossible, as both species share the same highly differentiated haplotypes due to introgression. Nuclear gene markers obtained through double digest restriction site associate sequencing (ddRAD seq), however, can reliably distinguish both species, yet the method is expensive as well as time-consuming and therefore not practicable for species determination. To facilitate accurate species identification without sequencing genome-wide markers, we developed nine diagnostic nuclear RFLP markers based on ddRAD seq data. The markers were successfully tested on geographically distinct populations of the two Sericostoma species in western Germany, on known hybrids, and on another sericostomatid caddisfly species, Oecismus monedula (Hagen, 1859) that sometimes shares the habitat and can be morphologically confounded with Sericostoma. We describe a simple and fast protocol for reliable species identification of S. personatum and S. flavicorne independent of the life cycle stage of the specimens.

8.
Cell Death Dis ; 9(5): 470, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29686375

RESUMO

Growth factor withdrawal induces rapid apoptosis via mitochondrial outer membrane permeabilization. We had previously observed that cell death of IL-3-dependent Ba/F3 cells, induced by removal of the growth factor, required the activity of the kinase GSK-3. Employing CRISPR/Cas9-mediated gene knockout, we aimed to identify pro-apoptotic GSK-3 regulated factors in this process. Knockout of either Puma or Bim demonstrated that the induction of Puma, but not Bim, was crucial for apoptosis induced by IL-3 deprivation. Thus, we aimed at identifying the GSK-3-dependent PUMA regulator. Loss of FOXO3A reduced the induction of Puma, while additional loss of p53 completely repressed induction upon growth factor withdrawal. A constitutively active mutant of FOXO3A, which cannot be controlled by AKT directly, still required active GSK-3 for the full transcriptional induction of Puma and cell death upon IL-3 withdrawal. Thus, the suppression of GSK-3 is the key function of PI3K signaling in order to prevent the induction of Puma by FOXO3A and p53 and thereby apoptosis upon growth factor withdrawal.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose , Quinase 3 da Glicogênio Sintase/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais , Proteínas Reguladoras de Apoptose/genética , Quinase 3 da Glicogênio Sintase/genética , Células HCT116 , Células HEK293 , Humanos , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas/genética
9.
Sci Total Environ ; 633: 875-891, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29602123

RESUMO

Local adaptation is of fundamental importance for populations to cope with fast, human-mediated environmental changes. In the past, analyses of local adaptation were restricted to few model species. Nowadays, due to the increased affordability of high-throughput sequencing, local adaptation can be studied much easier by searching for patterns of positive selection using genomic data. In the present study, we analysed effects of wastewater treatment plant and ore mining effluents on stream invertebrate populations. The two different anthropogenic stressors have impacted on stream ecosystems over different time scales and with different potencies. As target organisms we selected two macroinvertebrate species with different life histories and dispersal capacities: the caddisfly Glossosoma conformis and the flatworm Dugesia gonocephala. We applied a genome-wide genetic marker technique, termed ddRAD (double digest restriction site associated DNA) sequencing, to identify local adaptation. Ten and 18% of all loci were identified as candidate loci for local adaptation in D. gonocephala and G. conformis, respectively. However, after stringent re-evaluation of the genomic data, strong evidence for local adaptation remained only for one population of the flatworm D. gonocephala affected by high copper concentration from ore mining. One of the corresponding candidate loci is arnt, a gene associated with the response to xenobiotics and potentially involved in metal detoxification. Our results support the hypotheses that local adaptation is more likely to play a central role in environments impacted by a stronger stressor for a longer time and that it is more likely to occur in species with lower migration rates. However, these findings have to be interpreted cautiously, as several confounding factors may have limited the possibility to detect local adaptation. Our study highlights how genomic tools can be used to study the adaptability and thus resistance of natural populations to changing environments and we discuss prospects and limitations of the methods.


Assuntos
Insetos/fisiologia , Planárias/fisiologia , Águas Residuárias/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Organismos Aquáticos/fisiologia , Genômica , Mineração , Eliminação de Resíduos Líquidos
10.
EMBO Rep ; 19(2): 244-256, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29335245

RESUMO

The acetyltransferase TIP60 is regulated by phosphorylation, and we have previously shown that phosphorylation of TIP60 on S86 by GSK-3 promotes p53-mediated induction of the BCL-2 protein PUMA. TIP60 phosphorylation by GSK-3 requires a priming phosphorylation on S90, and here, we identify CDK9 as a TIP60S90 kinase. We demonstrate that a phosphorylation-deficient mutant, TIP60S90A, exhibits reduced interaction with chromatin, histone 3 and RNA Pol II, while its association with the TIP60 complex subunit EPC1 is not affected. Consistently, we find a diminished association of TIP60S90A with the MYC gene. We show that cells expressing TIP60S90A, but also TIP60S86A, which retains S90 phosphorylation, exhibit reduced histone 4 acetylation and proliferation. Thus, our data indicate that, during transcription, phosphorylation of TIP60 at two sites has different regulatory effects on TIP60, whereby S90 phosphorylation controls association with the transcription machinery, and S86 phosphorylation is regulating TIP60 HAT activity.


Assuntos
Quinase 9 Dependente de Ciclina/metabolismo , Lisina Acetiltransferase 5/metabolismo , Transcrição Gênica , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Cromatina/genética , Cromatina/metabolismo , Histonas/metabolismo , Humanos , Lisina Acetiltransferase 5/química , Modelos Biológicos , Proteínas Nucleares/metabolismo , Fosforilação , Ligação Proteica , RNA Polimerase II/metabolismo , Serina/química , Fatores de Transcrição/metabolismo
11.
Ecol Evol ; 8(2): 1063-1072, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29375779

RESUMO

DNA barcoding utilizes short standardized DNA sequences to identify species and is increasingly used in biodiversity assessments. The technique has unveiled an unforeseeably high number of morphologically cryptic species. However, if speciation has occurred relatively recently and rapidly, the use of single gene markers, and especially the exclusive use of mitochondrial markers, will presumably fail in delimitating species. Therefore, the true number of biological species might be even higher. One mechanism that can result in rapid speciation is hybridization of different species in combination with polyploidization, that is, allopolyploid speciation. In this study, we analyzed the population genetic structure of the polyploid freshwater snail Ancylus fluviatilis, for which allopolyploidization was postulated as a speciation mechanism. DNA barcoding has already revealed four cryptic species within A. fluviatilis (i.e., A. fluviatilis s. str., Ancylus sp. A-C), but early allozyme data even hint at the presence of additional cryptic lineages in Central Europe. We combined COI sequencing with high-resolution genome-wide SNP data (ddRAD data) to analyze the genetic structure of A. fluviatilis populations in a Central German low mountain range (Sauerland). The ddRAD data results indicate the presence of three cryptic species within A. fluviatilis s. str. occurring in sympatry and even syntopy, whereas mitochondrial sequence data only support the existence of one species, with shared haplotypes between species. Our study hence points to the limitations of DNA barcoding when dealing with organismal groups where speciation is assumed to have occurred rapidly, for example, through the process of allopolyploidization. We therefore emphasize that single marker DNA barcoding can underestimate the true species diversity and argue in strong favor of using genome-wide data for species delimitation in such groups.

12.
Mol Ecol Resour ; 18(3): 681-690, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29194981

RESUMO

High-throughput sequencing makes it possible to evaluate thousands of genetic markers across genomes and populations. Reduced-representation sequencing approaches, like double-digest restriction site-associated DNA sequencing (ddRADseq), are frequently applied to screen for genetic variation. In particular in nonmodel organisms where whole-genome sequencing is not yet feasible, ddRADseq has become popular as it allows genomewide assessment of variation patterns even in the absence of other genomic resources. However, while many tools are available for the analysis of ddRADseq data, few options exist to simulate ddRADseq data in order to evaluate the accuracy of downstream tools. The available tools either focus on the optimization of ddRAD experiment design or do not provide the information necessary for a detailed evaluation of different ddRAD analysis tools. For this task, a ground truth, that is, the underlying information of all effects in the data set, is required. Therefore, we here present ddrage, the ddRAD Data Set Generator, that allows both developers and users to evaluate their ddRAD analysis software. ddrage allows the user to adjust many parameters such as coverage and rates of mutations, sequencing errors or allelic dropouts, in order to generate a realistic simulated ddRADseq data set for given experimental scenarios and organisms. The simulated reads can be easily processed with available analysis software such as stacks or pyrad and evaluated against the underlying parameters used to generate the data to gauge the impact of different parameter values used during downstream data processing.


Assuntos
Conjuntos de Dados como Assunto , Análise de Sequência/métodos , Software , Simulação por Computador , Modelos Genéticos , Modelos Teóricos
13.
Mol Ecol ; 26(20): 5705-5715, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28792677

RESUMO

An increasing number of phylogenetic studies have reported discordances among nuclear and mitochondrial markers. These discrepancies are highly relevant to widely used biodiversity assessment approaches, such as DNA barcoding, that rely almost exclusively on mitochondrial markers. Although the theoretical causes of mito-nuclear discordances are well understood, it is often extremely challenging to determine the principal underlying factor in a given study system. In this study, we uncovered significant mito-nuclear discordances in a pair of sibling caddisfly species. Application of genome sequencing, ddRAD and DNA barcoding revealed ongoing hybridization, as well as historical hybridization in Pleistocene refugia, leading us to identify introgression as the ultimate cause of the observed discordance pattern. Our novel genomic data, the discovery of a European-wide hybrid zone and the availability of established techniques for laboratory breeding make this species pair an ideal model system for studying species boundaries with ongoing gene flow.


Assuntos
Evolução Biológica , Código de Barras de DNA Taxonômico , Hibridização Genética , Insetos/classificação , Animais , Núcleo Celular/genética , DNA Mitocondrial/genética , Europa (Continente) , Fluxo Gênico , Marcadores Genéticos , Genoma de Inseto , Filogenia , Análise de Sequência de DNA
14.
R Soc Open Sci ; 4(2): 160548, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28386419

RESUMO

The field of molecular ecology is transitioning from the use of small panels of classical genetic markers such as microsatellites to much larger panels of single nucleotide polymorphisms (SNPs) generated by approaches like RAD sequencing. However, few empirical studies have directly compared the ability of these methods to resolve population structure. This could have implications for understanding phenotypic plasticity, as many previous studies of natural populations may have lacked the power to detect genetic differences, especially over micro-geographic scales. We therefore compared the ability of microsatellites and RAD sequencing to resolve fine-scale population structure in a commercially important benthic invertebrate by genotyping great scallops (Pecten maximus) from nine populations around Northern Ireland at 13 microsatellites and 10 539 SNPs. The shells were then subjected to morphometric and colour analysis in order to compare patterns of phenotypic and genetic variation. We found that RAD sequencing was superior at resolving population structure, yielding higher Fst values and support for two distinct genetic clusters, whereas only one cluster could be detected in a Bayesian analysis of the microsatellite dataset. Furthermore, appreciable phenotypic variation was observed in size-independent shell shape and coloration, including among localities that could not be distinguished from one another genetically, providing support for the notion that these traits are phenotypically plastic. Taken together, our results suggest that RAD sequencing is a powerful approach for studying population structure and phenotypic plasticity in natural populations.

15.
Eur J Health Econ ; 18(6): 667-670, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27913941

RESUMO

In times of shrinking resources and pharmaceutical breakthrough situations, our value-assessing systems are stretched to their very limits. Assessing value is highly complex. Current value-assessment systems risk neglecting important factors, such as therapy duration, budget impact, or the importance of combination therapies. Especially when dealing with breakthrough therapies within high-prevalence indications, these factors play an important role in health care spending. When it comes to assessing value in Switzerland, the system is innovation and access-friendly; the price level of pharmaceutical products, however, is relatively high in comparison to neighboring countries. The Swiss pricing and reimbursement system can still improve in terms of efficiency and transparency.


Assuntos
Farmacoeconomia/estatística & dados numéricos , Gastos em Saúde/estatística & dados numéricos , Acessibilidade aos Serviços de Saúde/economia , Orçamentos , Análise Custo-Benefício , Custos e Análise de Custo/economia , Honorários Farmacêuticos , Hepatite C/tratamento farmacológico , Hepatite C/economia , Humanos , Sofosbuvir/economia , Sofosbuvir/uso terapêutico , Medicina Estatal , Suíça , Reino Unido
16.
BMC Evol Biol ; 16: 153, 2016 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-27473498

RESUMO

BACKGROUND: The actual connectivity between populations of freshwater organisms is largely determined by species biology, but is also influenced by many area- and site-specific factors, such as water pollution and habitat fragmentation. Therefore, the prediction of effective gene flow, even for well-studied organisms, is difficult. The amphipod crustacean Gammarus fossarum is a key invertebrate in freshwater ecosystems and contains many cryptic species. One of these species is the broadly distributed G. fossarum clade 11 (type B). In this study, we tested for factors driving the genetic structure of G. fossarum clade 11 in a human-impacted landscape at local and regional scales. To determine population structure, we analyzed the mitochondrial cytochrome c oxidase 1 (CO1) gene of 2,086 specimens from 54 sampling sites and microsatellite loci of 420 of these specimens from ten sites. RESULTS: We detected strong overall genetic differentiation between populations at regional and local scales with both independent marker systems, often even within few kilometers. Interestingly, we observed only a weak correlation of genetic distances with geographic distances or catchment boundaries. Testing for factors explaining the observed population structure revealed, that it was mostly the colonization history, which has influenced the structure rather than any of the chosen environmental factors. Whereas the number of in-stream barriers did not explain population differentiation, the few large water reservoirs in the catchment likely act as dispersal barriers. CONCLUSIONS: We showed that populations of Gammarus fossarum clade 11 are strongly isolated even at local scales in the human-impacted region. The observed genetic structure was best explained by the effects of random genetic drift acting independently on isolated populations after historical colonization events. Genetic drift in isolated populations was probably further enhanced by anthropogenic impacts, as G. fossarum is sensitive to many anthropogenic stressors. These findings highlight the importance of small-scale genetic studies to determine barriers restricting gene flow to prevent further loss of genetic diversity and maintain intact freshwater ecosystems.


Assuntos
Anfípodes/genética , Anfípodes/classificação , Animais , Ecossistema , Fluxo Gênico , Deriva Genética , Variação Genética , Repetições de Microssatélites , Rios
17.
Sci Rep ; 6: 22507, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26928527

RESUMO

Biodiversity hotspots are centers of biological diversity and particularly threatened by anthropogenic activities. Their true magnitude of species diversity and endemism, however, is still largely unknown as species diversity is traditionally assessed using morphological descriptions only, thereby ignoring cryptic species. This directly limits evidence-based monitoring and management strategies. Here we used molecular species delimitation methods to quantify cryptic diversity of the montane amphipods in the Irano-Anatolian and Caucasus biodiversity hotspots. Amphipods are ecosystem engineers in rivers and lakes. Species diversity was assessed by analysing two genetic markers (mitochondrial COI and nuclear 28S rDNA), compared with morphological assignments. Our results unambiguously demonstrate that species diversity and endemism is dramatically underestimated, with 42 genetically identified freshwater species in only five reported morphospecies. Over 90% of the newly recovered species cluster inside Gammarus komareki and G. lacustris; 69% of the recovered species comprise narrow range endemics. Amphipod biodiversity is drastically underestimated for the studied regions. Thus, the risk of biodiversity loss is significantly greater than currently inferred as most endangered species remain unrecognized and/or are only found locally. Integrative application of genetic assessments in monitoring programs will help to understand the true magnitude of biodiversity and accurately evaluate its threat status.


Assuntos
Anfípodes/genética , Biodiversidade , DNA Mitocondrial/genética , Monitorização de Parâmetros Ecológicos , Complexo IV da Cadeia de Transporte de Elétrons/genética , RNA Ribossômico 28S/genética , Animais , Ásia Ocidental , Biologia de Ecossistemas de Água Doce , Marcadores Genéticos/genética , Variação Genética
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