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1.
Nat Commun ; 14(1): 5620, 2023 09 12.
Article in English | MEDLINE | ID: mdl-37699868

ABSTRACT

Heliconius butterflies, a speciose genus of Müllerian mimics, represent a classic example of an adaptive radiation that includes a range of derived dietary, life history, physiological and neural traits. However, key lineages within the genus, and across the broader Heliconiini tribe, lack genomic resources, limiting our understanding of how adaptive and neutral processes shaped genome evolution during their radiation. Here, we generate highly contiguous genome assemblies for nine Heliconiini, 29 additional reference-assembled genomes, and improve 10 existing assemblies. Altogether, we provide a dataset of annotated genomes for a total of 63 species, including 58 species within the Heliconiini tribe. We use this extensive dataset to generate a robust and dated heliconiine phylogeny, describe major patterns of introgression, explore the evolution of genome architecture, and the genomic basis of key innovations in this enigmatic group, including an assessment of the evolution of putative regulatory regions at the Heliconius stem. Our work illustrates how the increased resolution provided by such dense genomic sampling improves our power to generate and test gene-phenotype hypotheses, and precisely characterize how genomes evolve.


Subject(s)
Butterflies , Animals , Genome Size , Butterflies/genetics , Genomics , Phenotype , Phylogeny
2.
PeerJ ; 9: e11523, 2021.
Article in English | MEDLINE | ID: mdl-34178447

ABSTRACT

Chemical defences against predators underlie the evolution of aposematic coloration and mimicry, which are classic examples of adaptive evolution. Surprisingly little is known about the roles of ecological and evolutionary processes maintaining defence variation, and how they may feedback to shape the evolutionary dynamics of species. Cyanogenic Heliconius butterflies exhibit diverse warning color patterns and mimicry, thus providing a useful framework for investigating these questions. We studied intraspecific variation in de novo biosynthesized cyanogenic toxicity and its potential ecological and evolutionary sources in wild populations of Heliconius erato along environmental gradients, in common-garden broods and with feeding treatments. Our results demonstrate substantial intraspecific variation, including detectable variation among broods reared in a common garden. The latter estimate suggests considerable evolutionary potential in this trait, although predicting the response to selection is likely complicated due to the observed skewed distribution of toxicity values and the signatures of maternal contributions to the inheritance of toxicity. Larval diet contributed little to toxicity variation. Furthermore, toxicity profiles were similar along steep rainfall and altitudinal gradients, providing little evidence for these factors explaining variation in biosynthesized toxicity in natural populations. In contrast, there were striking differences in the chemical profiles of H. erato from geographically distant populations, implying potential local adaptation in the acquisition mechanisms and levels of defensive compounds. The results highlight the extensive variation and potential for adaptive evolution in defense traits for aposematic and mimetic species, which may contribute to the high diversity often found in these systems.

3.
Swiss Med Wkly ; 151: w20460, 2021 03 01.
Article in English | MEDLINE | ID: mdl-33705563

ABSTRACT

BACKGROUND: Hepatitis C virus (HCV) infections in Switzerland are mainly related to intravenous drug use. Since 2017, all patients with chronic hepatitis C can be treated with direct-acting antivirals (DAAs) irrespective of fibrosis stage. In March 2019, the Federal Office of Public Health (FOPH) published guidelines for HCV management in people who use drugs. To achieve HCV elimination by 2030, 80% treatment uptake is necessary. AIM: To evaluate the benefit of interferon-based and interferon-free HCV treatment in patients on opioid agonist therapy (OAT) and monitor HCV elimination, a 2-year study commissioned by the FOPH and conducted within the Swiss Association for the Medical Management in Substance Users (SAMMSU) cohort was performed. METHODS: Since 2014, the SAMMSU cohort has recruited OAT patients from eight different centres throughout Switzerland. In addition to yearly follow up, cross-sectional data were collected at the time-points 1 May 2017, 1 May 2018 and 1 May 2019. HCV treatment uptake, adherence and success, as well as reinfection rates, the effect of early versus late treatment and the efficacy of the “treatment-as-prevention” approach were analysed. RESULTS: Between 1 May 2017 and 1 May 2019, the number of patients enrolled into the SAMMSU cohort increased from 623 to 900: 78% were male, the median age was 45 years, 81% had ever used intravenous drugs, 13% were human immunodeficiency virus (HIV) positive and 66% were HCV antibody positive. HCV treatment up to 2012 was exclusively interferon based (maximum 21 patients/year) and since 2016 exclusively interferon free (102 patients in 2017). Treatment success increased from 57% (112/198; interferon based) to 97% (261/268; interferon free) irrespective of cirrhosis or prior non-response to interferon. Simultaneously, treatments became shorter and better tolerated in the interferon-free era, resulting in fewer preterm stops (17% vs 1%) and adherence problems (9% vs 2%). Between 2015 and 2018, the proportion of patients with no/mild fibrosis (F0/F1) at first HCV treatment increased from 0% to 61%. Earlier treatment reduced the duration of infectiousness. Between 1 May 2017 and 1 May 2019, the proportion of chronic hepatitis C patients ever treated increased from 62% (198/321) to 80% (391/490). In parallel, the HCV-RNA prevalence among HCV antibody-positive patients declined from 36% (139/385) to 19% (113/593). The reinfection rate after successful treatment was 2.7/100 person-years. The number of HCV first diagnoses per year decreased from >20 up to 2015 to <10 in 2017 and 2018. CONCLUSION: With nearly 100% DAA treatment success and a low reinfection rate, treatment uptake directly translates into a reduction of HCV-RNA prevalence. Eighty percent treatment uptake is feasible in OAT patients, and adherence and treatment success are not worse than in other populations. Duration of infectiousness and thus HCV transmission can be reduced by early detection and treatment of chronic hepatitis C.


Subject(s)
HIV Infections , Hepatitis C, Chronic , Hepatitis C , Analgesics, Opioid , Antiviral Agents/therapeutic use , Cross-Sectional Studies , HIV Infections/drug therapy , Hepacivirus , Hepatitis C/drug therapy , Hepatitis C/epidemiology , Hepatitis C, Chronic/drug therapy , Hepatitis C, Chronic/epidemiology , Humans , Male , Middle Aged , Switzerland/epidemiology
4.
Biol Lett ; 17(3): 20200863, 2021 03.
Article in English | MEDLINE | ID: mdl-33784874

ABSTRACT

Host plant specialization is a major force driving ecological niche partitioning and diversification in insect herbivores. The cyanogenic defences of Passiflora plants keep most herbivores at bay, but not the larvae of Heliconius butterflies, which can both sequester and biosynthesize cyanogenic compounds. Here, we demonstrate that both Heliconius cydno chioneus and H. melpomene rosina have remarkable plasticity in their chemical defences. When feeding on Passiflora species with cyanogenic compounds that they can readily sequester, both species downregulate the biosynthesis of these compounds. By contrast, when fed on Passiflora plants that do not contain cyanogenic glucosides that can be sequestered, both species increase biosynthesis. This biochemical plasticity comes at a fitness cost for the more specialist H. m. rosina, as adult size and weight for this species negatively correlate with biosynthesis levels, but not for the more generalist H. c. chioneus. By contrast, H. m rosina has increased performance when sequestration is possible on its specialized host plant. In summary, phenotypic plasticity in biochemical responses to different host plants offers these butterflies the ability to widen their range of potential hosts within the Passiflora genus, while maintaining their chemical defences.


Subject(s)
Butterflies , Passiflora , Adaptation, Physiological , Animals , Larva , Plants
5.
Ecol Evol ; 10(5): 2677-2694, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32185010

ABSTRACT

Evolutionary convergence of color pattern in mimetic species is tightly linked with the evolution of chemical defenses. Yet, the evolutionary forces involved in natural variations of chemical defenses in aposematic species are still understudied. Herein, we focus on the evolution of chemical defenses in the butterfly tribe Heliconiini. These neotropical butterflies contain large concentrations of cyanogenic glucosides, cyanide-releasing compounds acting as predator deterrent. These compounds are either de novo synthesized or sequestered from their Passiflora host plant, so that their concentrations may depend on host plant specialization and host plant availability. We sampled 375 wild Heliconiini butterflies across Central and South America, covering 43% species of this clade, and quantify individual variations in the different CGs using liquid chromatography coupled with tandem mass spectrometry. We detected new compounds and important variations in chemical defenses both within and among species. Based on the most recent and well-studied phylogeny of Heliconiini, we show that ecological factors such as mimetic interactions and host plant specialization have a significant association with chemical profiles, but these effects are largely explained by phylogenetic relationships. Our results therefore suggest that shared ancestries largely contribute to chemical defense variation, pointing out at the interaction between historical and ecological factors in the evolution of Müllerian mimicry.

6.
Insect Biochem Mol Biol ; 116: 103259, 2020 01.
Article in English | MEDLINE | ID: mdl-31698083

ABSTRACT

Heliconius butterflies are highly specialized in Passiflora plants, laying eggs and feeding as larvae only on them. Interestingly, both Heliconius butterflies and Passiflora plants contain cyanogenic glucosides (CNglcs). While feeding on specific Passiflora species, Heliconius melpomene larvae are able to sequester simple cyclopentenyl CNglcs, the most common CNglcs in this plant genus. Yet, aromatic, aliphatic, and modified CNglcs have been reported in Passiflora species and they were never tested for sequestration by heliconiine larvae. As other cyanogenic lepidopterans, H. melpomene also biosynthesize the aliphatic CNglcs linamarin and lotaustralin, and their toxicity does not rely exclusively on sequestration. Although the genes encoding the enzymes in the CNglc biosynthesis have not yet been biochemically characterized in butterflies, the cytochromes P450 CYP405A4, CYP405A5, CYP405A6 and CYP332A1 have been hypothesized to be involved in this pathway in H. melpomene. In this study, we determine how the CNglc composition and expression of the putative P450s involved in the biosynthesis of these compounds vary at different developmental stages of Heliconius butterflies. We also establish which kind of CNglcs H. melpomene larvae can sequester from Passiflora. By analysing the chemical composition of the haemolymph from larvae fed with different Passiflora diets, we show that H. melpomene is able to sequestered prunasin, an aromatic CNglcs, from P. platyloba. They are also able to sequester amygdalin, gynocardin, [C13/C14]linamarin and [C13/C14]lotaustralin painted on the plant leaves. The CNglc tetraphyllin B-sulphate from P. caerulea is not detected in the larval haemolymph, suggesting that such modified CNglcs cannot be sequestered by Heliconius. Although pupae and virgin adults contain dihydrogynocardin resulting from larval sequestration, this compound was metabolized during adulthood, and not used as nuptial gift or transferred to the offspring. Thus, we speculate that dihydrogynocardin is catabolized to recycle nitrogen and glucose, and/or to produce fitness signals during courtship. Mature adults have a higher concentration of CNglcs than any other developmental stages due to increased de novo biosynthesis of linamarin and lotaustralin. Accordingly, all CYP405As are expressed in adults, whereas larvae mostly express CYP405A4. Our results shed light on the importance of CNglcs for Heliconius biology and their coevolution with Passiflora.


Subject(s)
Butterflies/metabolism , Glycosides/biosynthesis , Glycosides/metabolism , Animals , Biological Coevolution , Butterflies/chemistry , Butterflies/enzymology , Butterflies/growth & development , Cytochrome P-450 Enzyme System/genetics , Cytochrome P-450 Enzyme System/metabolism , Gene Expression Profiling , Glucosides/metabolism , Herbivory , Larva/enzymology , Larva/metabolism , Life Cycle Stages/physiology , Nitriles/metabolism , Passiflora/chemistry
7.
J Transl Med ; 17(1): 370, 2019 11 12.
Article in English | MEDLINE | ID: mdl-31718661

ABSTRACT

The purpose of the present work is to underline the importance of obtaining a standardized procedure to ensure and evaluate both clinical and research usability of human tissue samples. The study, which was carried out by the Biospecimen Science Working Group of the Spanish Biobank Network, is based on a general overview of the current situation about quality assurance in human tissue biospecimens. It was conducted an exhaustive review of the analytical techniques used to evaluate the quality of human tissue samples over the past 30 years, as well as their reference values if they were published, and classified them according to the biomolecules evaluated: (i) DNA, (ii) RNA, and (iii) soluble or/and fixed proteins for immunochemistry. More than 130 publications released between 1989 and 2019 were analysed, most of them reporting results focused on the analysis of tumour and biopsy samples. A quality assessment proposal with an algorithm has been developed for both frozen tissue samples and formalin-fixed paraffin-embedded (FFPE) samples, according to the expected quality of sample based on the available pre-analytical information and the experience of the participants in the Working Group. The high heterogeneity of human tissue samples and the wide number of pre-analytic factors associated to quality of samples makes it very difficult to harmonize the quality criteria. However, the proposed method to assess human tissue sample integrity and antigenicity will not only help to evaluate whether stored human tissue samples fit for the purpose of biomarker development, but will also allow to perform further studies, such as assessing the impact of different pre-analytical factors on very well characterized samples or evaluating the readjustment of tissue sample collection, processing and storing procedures. By ensuring the quality of the samples used on research, the reproducibility of scientific results will be guaranteed.


Subject(s)
Biological Specimen Banks/standards , Biomedical Research/standards , Evidence-Based Medicine , Quality Assurance, Health Care , Humans , Paraffin Embedding , Spain , Tissue Fixation
8.
Ecol Evol ; 9(9): 5079-5093, 2019 May.
Article in English | MEDLINE | ID: mdl-31110663

ABSTRACT

The colorful heliconiine butterflies are distasteful to predators due to their content of defense compounds called cyanogenic glucosides (CNglcs), which they biosynthesize from aliphatic amino acids. Heliconiine larvae feed exclusively on Passiflora plants where ~30 kinds of CNglcs have been reported. Among them, some CNglcs derived from cyclopentenyl glycine can be sequestered by some Heliconius species. In order to understand the evolution of biosynthesis and sequestration of CNglcs in these butterflies and its consequences for their arms race with Passiflora plants, we analyzed the CNglc distribution in selected heliconiine and Passiflora species. Sequestration of cyclopentenyl CNglcs is not an exclusive trait of Heliconius, since these compounds were present in other heliconiines such as Philaethria, Dryas and Agraulis, and in more distantly related genera Cethosia and Euptoieta. Thus, it is likely that the ability to sequester cyclopentenyl CNglcs arose in an ancestor of the Heliconiinae subfamily. Biosynthesis of aliphatic CNglcs is widespread in these butterflies, although some species from the sara-sapho group seem to have lost this ability. The CNglc distribution within Passiflora suggests that they might have diversified their cyanogenic profile to escape heliconiine herbivory. This systematic analysis improves our understanding on the evolution of cyanogenesis in the heliconiine-Passiflora system.

9.
Clin Infect Dis ; 69(11): 1980-1986, 2019 11 13.
Article in English | MEDLINE | ID: mdl-30715266

ABSTRACT

BACKGROUND: Hepatitis C virus (HCV) among people living in detention (PLD) is typically high in many countries including Switzerland, where it is estimated that the HCV prevalence rate is between 5.7% and 6.2%. In Switzerland, the existing screening strategy involves routine screening of PLD who indicate they are from HCV high-risk populations based on questionnaire responses upon entry to the detention center, rather than an offer to screen all PLD. METHODS: A cost-effectiveness analysis from a Swiss healthcare provider perspective was conducted by combining a 5-year decision tree screening model with results from a Markov model of HCV treatment outcomes. This model explored the cost-effectiveness of increased HCV screening to cover all PLD compared to the current approach, using a standard test package and subsequent treatment with a single-tablet regimen in Swiss custodial settings. Sensitivity and scenario analyses examined the uncertainty of results. RESULTS: At the willingness-to-pay threshold of 100 000 Swiss Francs (CHF) per quality-adjusted life-year (QALY), comprehensive general screening was cost-effective compared to current risk-based screening, with a base case incremental cost-effectiveness ratio of CHF 14 312 per QALY. The net monetary benefit of screening the whole PLD population was CHF 23 298 046 and CHF 4298 per person. The proportion of PLD tested was predicted to increase from 13.6% to 67.0% under comprehensive screening. CONCLUSION: The results showed that comprehensive screening strategies in detention centers in Switzerland can be cost-effective, with the probabilistic sensitivity analysis estimating an 82.3% probability of cost-effectiveness.


Subject(s)
Antiviral Agents/therapeutic use , Hepatitis C, Chronic/diagnosis , Hepatitis C, Chronic/drug therapy , Mass Screening/economics , Cost-Benefit Analysis , Female , Health Care Costs , Hepacivirus/drug effects , Hepacivirus/pathogenicity , Hepatitis C/diagnosis , Hepatitis C/drug therapy , Humans , Male , Quality-Adjusted Life Years , Switzerland
10.
Ecology ; 100(1): e02525, 2019 01.
Article in English | MEDLINE | ID: mdl-30317556

ABSTRACT

Primates play an important role in ecosystem functioning and offer critical insights into human evolution, biology, behavior, and emerging infectious diseases. There are 26 primate species in the Atlantic Forests of South America, 19 of them endemic. We compiled a dataset of 5,472 georeferenced locations of 26 native and 1 introduced primate species, as hybrids in the genera Callithrix and Alouatta. The dataset includes 700 primate communities, 8,121 single species occurrences and 714 estimates of primate population sizes, covering most natural forest types of the tropical and subtropical Atlantic Forest of Brazil, Paraguay and Argentina and some other biomes. On average, primate communities of the Atlantic Forest harbor 2 ± 1 species (range = 1-6). However, about 40% of primate communities contain only one species. Alouatta guariba (N = 2,188 records) and Sapajus nigritus (N = 1,127) were the species with the most records. Callicebus barbarabrownae (N = 35), Leontopithecus caissara (N = 38), and Sapajus libidinosus (N = 41) were the species with the least records. Recorded primate densities varied from 0.004 individuals/km2 (Alouatta guariba at Fragmento do Bugre, Paraná, Brazil) to 400 individuals/km2 (Alouatta caraya in Santiago, Rio Grande do Sul, Brazil). Our dataset reflects disparity between the numerous primate census conducted in the Atlantic Forest, in contrast to the scarcity of estimates of population sizes and densities. With these data, researchers can develop different macroecological and regional level studies, focusing on communities, populations, species co-occurrence and distribution patterns. Moreover, the data can also be used to assess the consequences of fragmentation, defaunation, and disease outbreaks on different ecological processes, such as trophic cascades, species invasion or extinction, and community dynamics. There are no copyright restrictions. Please cite this Data Paper when the data are used in publications. We also request that researchers and teachers inform us of how they are using the data.

11.
J Viral Hepat ; 26(2): 236-245, 2019 02.
Article in English | MEDLINE | ID: mdl-30338887

ABSTRACT

People who inject drugs (PWID) are a key high-risk group for Hepatitis C Virus (HCV) infection due to the sharing of needles and drug-preparation equipment. However, only approximately 50% of PWID are currently screened for HCV in Switzerland. At present, screening of PWID occurs in general practice via venepuncture. Compared to venepuncture, screening via rapid antibody saliva and dried blood spot (DBS) tests is well adapted to PWID, who typically have difficult venous access. The cost-effectiveness of an increased access screening programme of PWID (increased screening using rapid antibody saliva tests and DBS tests [semi-quantitative viraemia and viral genotype]) was analysed through a decision tree screening model combined with the outputs of a Markov treatment model. Sensitivity and scenario analyses examined the uncertainty of results. At a willingness to pay (WTP) threshold of CHF 100 000 (USD 105 000) per quality-adjusted life year (QALY), the increased access screening programme was cost-effective compared to current screening, with a base case incremental cost-effectiveness ratio of CHF 7 940 (USD 8337) per QALY. The net monetary benefit was CHF 959 802 668 (USD 1 007 792 801) for the PWID population and CHF 94 469 (USD 99 192) per person. The increased access screening programme had a 97.0% probability of being cost-effective compared to the current screening method at the WTP threshold of CHF 100 000 (USD 105 000). The results showed an increased access screening programme that uses tests which are better suited to the PWID population to be more cost-effective, due to the increased uptake that rapid antibody saliva and DBS tests generate.


Subject(s)
Cost-Benefit Analysis , Dried Blood Spot Testing/economics , Hepatitis C/diagnosis , Mass Screening/economics , Saliva/immunology , Substance Abuse, Intravenous/epidemiology , Adult , Antibodies, Viral/analysis , Drug Users/statistics & numerical data , Female , Health Care Costs , Hepatitis C/economics , Hepatitis C/epidemiology , Humans , Male , Mass Screening/methods , Substance Abuse, Intravenous/complications , Switzerland/epidemiology
12.
Int J Drug Policy ; 62: 94-103, 2018 12.
Article in English | MEDLINE | ID: mdl-30384028

ABSTRACT

BACKGROUND: Direct-acting antiviral therapy for hepatitis C virus (HCV) infection is safe and effective, but there are little data among people who have recently injected drugs. This study evaluated the efficacy, and safety of paritaprevir/ritonavir, ombitasvir, dasabuvir with or without ribavirin for chronic HCV genotype (G) 1 among people with recent injecting drug use and/or receiving OST. METHODS: D3FEAT is an international open-label study that recruited treatment-naïve participants with recent injecting drug use (previous 6 months) and/or receiving OST with chronic HCV G1 infection between June 2016 and February 2017 in seven countries. Participants received paritaprevir/ritonavir, ombitasvir, dasabuvir with (G1a) or without ribavirin (G1b) administered twice daily in a one-week electronic blister pack (records timing of each dose) for 12 weeks. The primary endpoint was undetectable HCV RNA 12 weeks post-treatment (SVR12). RESULTS: Among 87 participants (median age 48 years), 23% were female, 8% had cirrhosis, and 90% had G1a. Overall, 71% were receiving OST, 61% injected in the previous six months, 45% injected in the previous month, and 15% injected > daily. Treatment completion was 97% (84 of 87). There were no virological breakthroughs, but three discontinuations (loss to follow-up, n = 1; non-adherence, n = 1; incarceration, n = 1). SVR was 91% (79 of 87, 95% CI, 83%-96%). Five participants who completed treatment did not have SVR (loss to follow-up, n = 1; death, n = 1; virologic relapse, n = 3). Drug use prior to and during treatment did not impact SVR12. Treatment-related adverse events were observed in 46 (53%) patients (six grade 3, no grade 4). Five (6%) patients had at least one serious adverse event (two possibly/probably related to therapy; nausea and myoclonus). Two cases of reinfection were observed. CONCLUSION: Paritaprevir/ritonavir, ombitasvir, and dasabuvir with or without ribavirin for 12 weeks is effective among people with HCV genotype 1 with recent injecting drug use and/or receiving OST.


Subject(s)
Antiviral Agents/therapeutic use , Hepatitis C, Chronic/drug therapy , Opiate Substitution Treatment/methods , Substance Abuse, Intravenous/drug therapy , Substance Abuse, Intravenous/epidemiology , 2-Naphthylamine , Adult , Anilides/therapeutic use , Antiviral Agents/adverse effects , Carbamates/therapeutic use , Cyclopropanes , Drug Administration Schedule , Drug Therapy, Combination , Hepacivirus/genetics , Hepatitis C, Chronic/virology , Humans , Lactams, Macrocyclic , Macrocyclic Compounds/therapeutic use , Male , Medication Adherence , Middle Aged , Opiate Substitution Treatment/statistics & numerical data , Proline/analogs & derivatives , Qualitative Research , RNA, Viral/analysis , Ribavirin/therapeutic use , Ritonavir/therapeutic use , Substance Abuse, Intravenous/virology , Sulfonamides/therapeutic use , Sustained Virologic Response , Treatment Outcome , Uracil/analogs & derivatives , Uracil/therapeutic use , Valine
13.
Insects ; 9(2)2018 May 03.
Article in English | MEDLINE | ID: mdl-29751568

ABSTRACT

Chemical defences are key components in insect⁻plant interactions, as insects continuously learn to overcome plant defence systems by, e.g., detoxification, excretion or sequestration. Cyanogenic glucosides are natural products widespread in the plant kingdom, and also known to be present in arthropods. They are stabilised by a glucoside linkage, which is hydrolysed by the action of β-glucosidase enzymes, resulting in the release of toxic hydrogen cyanide and deterrent aldehydes or ketones. Such a binary system of components that are chemically inert when spatially separated provides an immediate defence against predators that cause tissue damage. Further roles in nitrogen metabolism and inter- and intraspecific communication has also been suggested for cyanogenic glucosides. In arthropods, cyanogenic glucosides are found in millipedes, centipedes, mites, beetles and bugs, and particularly within butterflies and moths. Cyanogenic glucosides may be even more widespread since many arthropod taxa have not yet been analysed for the presence of this class of natural products. In many instances, arthropods sequester cyanogenic glucosides or their precursors from food plants, thereby avoiding the demand for de novo biosynthesis and minimising the energy spent for defence. Nevertheless, several species of butterflies, moths and millipedes have been shown to biosynthesise cyanogenic glucosides de novo, and even more species have been hypothesised to do so. As for higher plant species, the specific steps in the pathway is catalysed by three enzymes, two cytochromes P450, a glycosyl transferase, and a general P450 oxidoreductase providing electrons to the P450s. The pathway for biosynthesis of cyanogenic glucosides in arthropods has most likely been assembled by recruitment of enzymes, which could most easily be adapted to acquire the required catalytic properties for manufacturing these compounds. The scattered phylogenetic distribution of cyanogenic glucosides in arthropods indicates that the ability to biosynthesise this class of natural products has evolved independently several times. This is corroborated by the characterised enzymes from the pathway in moths and millipedes. Since the biosynthetic pathway is hypothesised to have evolved convergently in plants as well, this would suggest that there is only one universal series of unique intermediates by which amino acids are efficiently converted into CNglcs in different Kingdoms of Life. For arthropods to handle ingestion of cyanogenic glucosides, an effective detoxification system is required. In butterflies and moths, hydrogen cyanide released from hydrolysis of cyanogenic glucosides is mainly detoxified by β-cyanoalanine synthase, while other arthropods use the enzyme rhodanese. The storage of cyanogenic glucosides and spatially separated hydrolytic enzymes (β-glucosidases and α-hydroxynitrile lyases) are important for an effective hydrogen cyanide release for defensive purposes. Accordingly, such hydrolytic enzymes are also present in many cyanogenic arthropods, and spatial separation has been shown in a few species. Although much knowledge regarding presence, biosynthesis, hydrolysis and detoxification of cyanogenic glucosides in arthropods has emerged in recent years, many exciting unanswered questions remain regarding the distribution, roles apart from defence, and convergent evolution of the metabolic pathways involved.

14.
Insects ; 9(1)2018 Mar 13.
Article in English | MEDLINE | ID: mdl-29534004

ABSTRACT

Honeybees (Apis mellifera) pollinate flowers and collect nectar from many important crops. White clover (Trifolium repens) is widely grown as a temperate forage crop, and requires honeybee pollination for seed set. In this study, using a quantitative LC-MS (Liquid Chromatography-Mass Spectrometry) assay, we show that the cyanogenic glucosides linamarin and lotaustralin are present in the leaves, sepals, petals, anthers, and nectar of T. repens. Cyanogenic glucosides are generally thought to be defense compounds, releasing toxic hydrogen cyanide upon degradation. However, increasing evidence indicates that plant secondary metabolites found in nectar may protect pollinators from disease or predators. In a laboratory survival study with chronic feeding of secondary metabolites, we show that honeybees can ingest the cyanogenic glucosides linamarin and amygdalin at naturally occurring concentrations with no ill effects, even though they have enzyme activity towards degradation of cyanogenic glucosides. This suggests that honeybees can ingest and tolerate cyanogenic glucosides from flower nectar. Honeybees retain only a portion of ingested cyanogenic glucosides. Whether they detoxify the rest using rhodanese or deposit them in the hive should be the focus of further research.

15.
Biol Rev Camb Philos Soc ; 93(1): 555-573, 2018 02.
Article in English | MEDLINE | ID: mdl-28901723

ABSTRACT

Heliconiines are called passion vine butterflies because they feed exclusively on Passiflora plants during the larval stage. Many features of Passiflora and heliconiines indicate that they have radiated and speciated in association with each other, and therefore this model system was one of the first examples used to exemplify coevolution theory. Three major adaptations of Passiflora plants supported arguments in favour of their coevolution with heliconiines: unusual variation of leaf shape within the genus; the occurrence of yellow structures mimicking heliconiine eggs; and their extensive diversity of defence compounds called cyanogenic glucosides. However, the protection systems of Passiflora plants go beyond these three features. Trichomes, mimicry of pathogen infection through variegation, and production of extrafloral nectar to attract ants and other predators of their herbivores, are morphological defences reported in this plant genus. Moreover, Passiflora plants are well protected chemically, not only by cyanogenic glucosides, but also by other compounds such as alkaloids, flavonoids, saponins, tannins and phenolics. Heliconiines can synthesize cyanogenic glucosides themselves, and their ability to handle these compounds was probably one of the most crucial adaptations that allowed the ancestor of these butterflies to feed on Passiflora plants. Indeed, it has been shown that Heliconius larvae can sequester cyanogenic glucosides and alkaloids from their host plants and utilize them for their own benefit. Recently, it was discovered that Heliconius adults have highly accurate visual and chemosensory systems, and the expansion of brain structures that can process such information allows them to memorize shapes and display elaborate pre-oviposition behaviour in order to defeat visual barriers evolved by Passiflora species. Even though the heliconiine-Passiflora model system has been intensively studied, the forces driving host-plant preference in these butterflies remain unclear. New studies have shown that host-plant preference seems to be genetically controlled, but in many species there is some plasticity in this choice and preferences can even be induced. Although much knowledge regarding the coevolution of Passiflora plants and heliconiine butterflies has accumulated in recent decades, there remain many exciting unanswered questions concerning this model system.


Subject(s)
Biological Coevolution , Butterflies/physiology , Feeding Behavior/physiology , Passiflora/physiology , Animals , Butterflies/genetics , Larva/physiology , Passiflora/genetics , Plant Leaves/chemistry , Plant Leaves/physiology
17.
Rev Med Suisse ; 13(544-545): 12-15, 2017 Jan 11.
Article in French | MEDLINE | ID: mdl-28703526

ABSTRACT

In 2016, the actuality for addictions in this edition addresses four points. Social neurosciences of addiction are of great importance regarding the vulnerabilities for addiction and for the recovery. Deep brain stimulation is emerging in the therapeutic panel coming from the clinical neurosciences for the addictions. Novelties in opioid agonists for the treatment of opiates dependence, with the apparition in the Swiss market of release morphine and of levomethadone. Cannabis and prison, a pilot study for the maintenance of abstinence in prison.


En 2016, l'actualité des addictions pour ce numéro concerne quatre points. Les neurosciences sociales de l'addiction, qui ont une grande importance en termes de vulnérabilité pour l'addiction mais aussi pour le rétablissement. La stimulation cérébrale profonde qui fait son apparition dans l'éventail thérapeutique issu des neurosciences cliniques pour les addictions. Les nouveautés du traitement agoniste opioïde de la dépendance aux opiacés avec l'apparition dans le marché suisse de la morphine retard puis de la lévométhadone. Des algorithmes sont proposés pour orienter le prescripteur. Cannabis et prison, une étude pilote pour le maintien de l'abstinence en prison.


Subject(s)
Behavior, Addictive , Substance-Related Disorders , Behavior, Addictive/epidemiology , Behavior, Addictive/therapy , Cannabis , Humans , Neurosciences/methods , Neurosciences/trends , Opioid-Related Disorders/epidemiology , Opioid-Related Disorders/therapy , Prisons , Substance-Related Disorders/epidemiology , Substance-Related Disorders/therapy
18.
World J Virol ; 5(2): 68-72, 2016 May 12.
Article in English | MEDLINE | ID: mdl-27175351

ABSTRACT

This review analyses current data concerning co-infection with hepatitis C virus (HCV) and human T lymphotropic virus (HTLV)-1/2 in people who inject drugs (PWID), with a particular focus on disease burden and global implications for virological outcome. In addition, the available treatment options for HTLV-1/2 are summarized and the ongoing and likely future research challenges are discussed. The data in this review was obtained from 34 articles on HCV/HTLV-1/2 co-infection in PWID retrieved from the PubMed literature database and published between 1997 and 2015. Despite unavailable estimates of the burden of HCV/HTLV-1/2 co-infection in general, the epidemiologic constellation of HTLV-1/2 shows high incidence in PWID with history of migration, incarceration, and other blood-borne infectious diseases such as HCV or human immunodeficiency virus. The most recent research data strongly suggest that HTLV-1 co-infection can influence HCV viral load, HCV sustained virological response to α-interferon treatment, and HCV-related liver disease progression. In short, outcome of HCV infection is worse in the context of HTLV-1 co-infection, yet more studies are needed to gain accurate estimations of the burden of HCV/HTLV-1/2 co-infections. Moreover, in the current era of new direct-acting antiviral treatments for HCV and proven HTLV-1/2 treatment options, prospective clinical and treatment studies should be carried out, with particular focus on the PWID patient population, with the aim of improving virological outcomes.

19.
Methods ; 77-78: 25-30, 2015 May.
Article in English | MEDLINE | ID: mdl-25697760

ABSTRACT

Prostate cancer is among the most frequent cancers in men, and despite its high rate of cure, the high number of cases results in an elevated mortality worldwide. Importantly, prostate cancer incidence is dramatically increasing in western societies in the past decades, suggesting that this type of tumor is exquisitely sensitive to lifestyle changes. Prostate cancer frequently exhibits alterations in the PTEN gene (inactivating mutations or gene deletions) or at the protein level (reduced protein expression or altered sub-cellular compartmentalization). The relevance of PTEN in this type of cancer is further supported by the fact that the sole deletion of PTEN in the murine prostate epithelium recapitulates many of the features of the human disease. In order to study the molecular alterations in prostate cancer, we need to overcome the methodological challenges that this tissue imposes. In this review we present protocols and methods, using PTEN as proof of concept, to study different molecular characteristics of prostate cancer.


Subject(s)
PTEN Phosphohydrolase/analysis , PTEN Phosphohydrolase/biosynthesis , Prostatic Neoplasms/metabolism , Tumor Suppressor Proteins/analysis , Tumor Suppressor Proteins/biosynthesis , Animals , Humans , Male , Mice , Mutation/genetics , PTEN Phosphohydrolase/genetics , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Tumor Suppressor Proteins/genetics
20.
J Antimicrob Chemother ; 70(3): 930-40, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25336166

ABSTRACT

OBJECTIVES: It is still debated if pre-existing minority drug-resistant HIV-1 variants (MVs) affect the virological outcomes of first-line NNRTI-containing ART. METHODS: This Europe-wide case-control study included ART-naive subjects infected with drug-susceptible HIV-1 as revealed by population sequencing, who achieved virological suppression on first-line ART including one NNRTI. Cases experienced virological failure and controls were subjects from the same cohort whose viraemia remained suppressed at a matched time since initiation of ART. Blinded, centralized 454 pyrosequencing with parallel bioinformatic analysis in two laboratories was used to identify MVs in the 1%-25% frequency range. ORs of virological failure according to MV detection were estimated by logistic regression. RESULTS: Two hundred and sixty samples (76 cases and 184 controls), mostly subtype B (73.5%), were used for the analysis. Identical MVs were detected in the two laboratories. 31.6% of cases and 16.8% of controls harboured pre-existing MVs. Detection of at least one MV versus no MVs was associated with an increased risk of virological failure (OR = 2.75, 95% CI = 1.35-5.60, P = 0.005); similar associations were observed for at least one MV versus no NRTI MVs (OR = 2.27, 95% CI = 0.76-6.77, P = 0.140) and at least one MV versus no NNRTI MVs (OR = 2.41, 95% CI = 1.12-5.18, P = 0.024). A dose-effect relationship between virological failure and mutational load was found. CONCLUSIONS: Pre-existing MVs more than double the risk of virological failure to first-line NNRTI-based ART.


Subject(s)
Antiretroviral Therapy, Highly Active/methods , Drug Resistance, Viral , HIV Infections/drug therapy , HIV Infections/virology , HIV-1/drug effects , Reverse Transcriptase Inhibitors/therapeutic use , Adult , Case-Control Studies , Cohort Studies , Computational Biology , Europe , Female , Genotype , HIV-1/genetics , HIV-1/isolation & purification , High-Throughput Nucleotide Sequencing , Humans , Male , Risk Assessment , Sequence Analysis, DNA , Treatment Failure , Young Adult
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