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1.
Int J Mol Sci ; 24(6)2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36982981

RESUMO

Computational approaches in immune-oncology therapies focus on using data-driven methods to identify potential immune targets and develop novel drug candidates. In particular, the search for PD-1/PD-L1 immune checkpoint inhibitors (ICIs) has enlivened the field, leveraging the use of cheminformatics and bioinformatics tools to analyze large datasets of molecules, gene expression and protein-protein interactions. Up to now, there is still an unmet clinical need for improved ICIs and reliable predictive biomarkers. In this review, we highlight the computational methodologies applied to discovering and developing PD-1/PD-L1 ICIs for improved cancer immunotherapies with a greater focus in the last five years. The use of computer-aided drug design structure- and ligand-based virtual screening processes, molecular docking, homology modeling and molecular dynamics simulations methodologies essential for successful drug discovery campaigns focusing on antibodies, peptides or small-molecule ICIs are addressed. A list of recent databases and web tools used in the context of cancer and immunotherapy has been compilated and made available, namely regarding a general scope, cancer and immunology. In summary, computational approaches have become valuable tools for discovering and developing ICIs. Despite significant progress, there is still a need for improved ICIs and biomarkers, and recent databases and web tools have been compiled to aid in this pursuit.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , Inibidores de Checkpoint Imunológico/uso terapêutico , Receptor de Morte Celular Programada 1 , Antígeno B7-H1 , Simulação de Acoplamento Molecular , Imunoterapia/métodos
2.
Pharmaceuticals (Basel) ; 17(7)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-39065722

RESUMO

Mefloquine (MQ) is an antimalarial medication prescribed to treat or malaria prevention.. When taken by children, vomiting usually occurs, and new doses of medication frequently need to be taken. So, developing pediatric medicines using taste-masked antimalarial drug complexes is mandatory for the success of mefloquine administration. The hypothesis that binding mefloquine to an ion-exchange resin (R) could circumvent the drug's bitter taste problem was proposed, and solid-state 13C cross-polarization magic angle spinning (CPMAS) NMR was able to follow MQ-R mixtures through chemical shift and relaxation measurements. The nature of MQ-R complex formation could then be determined. Impedimetric electronic tongue equipment also verified the resinate taste-masking efficiency in vitro. Variations in chemical shifts and structure dynamics measured by proton relaxation properties (e.g., T1ρH) were used as probes to follow the extension of mixing and specific interactions that would be present in MQ-R. A significant decrease in T1ρH values was observed for MQ carbons in MQ-R complexes, compared to the ones in MQ (from 100-200 ms in MQ to 20-50 ms in an MQ-R complex). The results evidenced that the cationic resin interacts strongly with mefloquine molecules in the formulation of a 1:1 ratio complex. Thus, 13C CPMAS NMR allowed the confirmation of the presence of a binding between mefloquine and polacrilin in the MQ-R formulation studied.

3.
BMC Cancer ; 13: 122, 2013 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-23497363

RESUMO

BACKGROUND: Supporting health care sector decisions using time-dependent endpoints (TDEs) such as time to progression (TTP), progression-free survival (PFS), and event-free survival (EFS) remains controversial. This study estimated the quantitative relationship between median TDE and median overall survival (OS) in multiple myeloma (MM) patients. METHODS: Studies (excluding allogeneic transplantation) published from 1970 to 2011 were systematically searched (PubMed). The nonparametric Spearman's rank correlation coefficient measured the association between median TDE and OS. The quantitative relationship between TDEs and OS was estimated with a two-step approach to a simultaneous Tobit model. RESULTS: We identified 153 studies: 230 treatment arms, 22,696 patients and mean study duration of 3.8 years. Mean of median TDEs was 22.5 months and median OS was 39.1 months. Correlation coefficients of median TTP, PFS, and EFS with median OS were 0.51 (P = 0.003), 0.75 (P < 0.0001), and 0.84 (P < 0.0001), respectively. We estimate a 2.5 month (95% confidence interval, 1.7-3.2) increase in median OS for each additional month reported for median TDEs. There was no evidence that this relationship differed by type of surrogate. CONCLUSION: TDEs predict OS in MM patients; this relationship may be valuable in clinical trial design, drug comparisons, and economic evaluation.


Assuntos
Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/terapia , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Intervalo Livre de Doença , Feminino , Transplante de Células-Tronco Hematopoéticas , Humanos , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Transplante Homólogo
4.
Front Nutr ; 10: 1043618, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37408985

RESUMO

The aim of this study was to investigate how consumers (n = 2,171) originated from South-Western Europe (Italy, Portugal, and Spain) perceive cultured "meat" (CM) and if their demographic characteristics (origin, gender, age, education, occupation, and meat consumption) are related to their willingness to try (WTT), to regularly eat (WTE) and to pay (WTP) for CM. We found the current respondents had an initially positive attitude towards CM: 49% of them perceived CM as "promising and/or acceptable" and 23% "fun and/or intriguing" whereas 29% considered it as "absurd and/or disgusting". In addition, 66 and 25% would be willing and not willing to try CM, respectively. However, 43% had no WTE for CM and, 94% would not pay more for CM compared to conventional meat. Age and especially occupation were good indicators of consumer acceptance of CM. Respondents of 18-30 years of age had the highest acceptance. Respondents outside the meat sector had the highest WTE and people working within the meat sector had the lowest WTE, scientists (within or outside the meat sector) had the highest WTT, people not scientists but within the meat sector had the lowest WTT. Additionally, we found that men are more likely to accept CM than women, Spanish-speaking consumers had the highest WTT and WTE, people with vegan and vegetarian diets may pay more for CM but generally no more than for conventional meat. The perceptions that CM may be more eco-friendly, ethical, safe and healthy than conventional meat, and to a lower extent, the perception that current meat production causes ethical and environmental problems are likely to be major motives for the current respondents to try, regularly eat and pay for CM. On the opposite, lower perceptions of CM benefits and of conventional meat weaknesses more generally, plus emotional resistance towards CM are main barriers to accept CM.

5.
Nat Commun ; 14(1): 7026, 2023 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-37919276

RESUMO

Surface antigenic variation is crucial for major pathogens that infect humans. To escape the immune system, they exploit various mechanisms. Understanding these mechanisms is important to better prevent and fight the deadly diseases caused. Those used by the fungus Pneumocystis jirovecii that causes life-threatening pneumonia in immunocompromised individuals remain poorly understood. Here, though this fungus is currently not cultivable, our detailed analysis of the subtelomeric sequence motifs and genes encoding surface proteins suggests that the system involves the reassortment of the repertoire of ca. 80 non-expressed genes present in each strain, from which single genes are retrieved for mutually exclusive expression. Dispersion of the new repertoires, supposedly by healthy carrier individuals, appears very efficient because identical alleles are observed in patients from different countries. Our observations reveal a unique strategy of antigenic variation. They also highlight the possible role in genome rearrangements of small imperfect mirror sequences forming DNA triplexes.


Assuntos
Mosaicismo , Pneumocystis carinii , Humanos , Pneumocystis carinii/genética , Variação Antigênica/genética , DNA Fúngico/genética
6.
mBio ; 13(4): e0085922, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-35726921

RESUMO

Pneumocystis species are obligate fungal biotrophs that colonize the lungs of mammals. They cause deadly pneumonia in immunocompromised hosts. The sexual phase seems obligate during their life cycle and essential for survival because it is believed to ensure proliferation and transmission between hosts. Here, we consider if the sexual phase is initiated by the fusion of two cells or by nucleus duplication in order to generate diploid cells that can undergo meiosis. The juxtaposition of the nucleus-associated organelles of pairs of cells with fused cytoplasmic membranes demonstrated that cell fusion can occur. Nevertheless, the frequency of cell fusion remains to be determined, and it cannot be excluded that both cell fusion and nucleus duplication are used to ensure the occurrence of the essential sexual phase. In vitro culturing of these fungi is a major milestone that could clarify the issue.


Assuntos
Pneumocystis , Animais , Fusão Celular , Diploide , Mamíferos , Meiose , Pneumocystis/genética , Reprodução
7.
Meat Sci ; 188: 108782, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35303657

RESUMO

Thirty-two bulls were assigned to four total mixed biodiverse haylage-based diets to evaluate the effects of partial substitution of grains by agroindustrial byproducts, sunflower seeds (SS) supplementation and haylage level on growth, in vitro methane production and carcass and meat quality. Dietary treatments included a grain-based diet with 30% grain and haylage:concentrate ratio (H:C) of 60:40 (DM basis) (MCe); a by-product-based diet where 50% of the grain was substituted for by-products (H:C, 60:40) (MBp); a byproducts diet with 10% sunflower seed and 90% (DM) MBp (H:C, 54:46) (MBpSS); and a byproducts, SS diet with increased haylage (H:C, 67.5:32.5) (HBpSS). Dry matter intake and growth rate were lower in HBpSS, but feed conversion ratio was unaffected by diet. In vitro methane emissions were reduced by SS. Meat colour and shear force were similar among diets. Lipid oxidation in cooked meat was reduced and fatty acid composition was improved with SS. Biodiverse haylage-based diets may be a viable option for finishing bulls.


Assuntos
Ração Animal , Helianthus , Ração Animal/análise , Animais , Bovinos , Dieta/veterinária , Suplementos Nutricionais , Grão Comestível , Masculino , Carne , Metano
8.
Res Vet Sci ; 144: 44-53, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35066314

RESUMO

The implication of high dietary level of Chlorella vulgaris, individually and supplemented with two carbohydrase mixtures, on pigs' health and liver metabolism was assessed in this study. Forty crossbred (Large White × Landrace sows crossed with Pietrain boars) entire male pigs were randomly allocated to the following feeding treatments (n = 10): cereal-soybean meal basal diet (control); basal diet with 5% C. vulgaris; basal diet with 5% C. vulgaris supplemented with 0.005% Rovabio® Excel AP; and basal diet with 5% C. vulgaris supplemented with 0.01% of a preselected four-CAZyme mixture. The trial lasted from 59.1 ± 5.69 kg of initial live weight to 101 ± 1.9 kg of slaughter weight. Data indicate that this high dietary level of C. vulgaris has impact on several blood parameters of finishing pigs. However, the most relevant health outcome observed was a strong immunosuppressive effect promoted by the microalga, which increases pigs' susceptibility to infection diseases. In addition, the dietary incorporation of C. vulgaris reduced the systemic antioxidant capacity of pigs. In turn, the dietary supplementation with the four-CAZyme mixture promoted a clear decrease on some blood parameters compared with the control group. Regarding hepatic lipids, pigs fed C. vulgaris diets, had an increased hepatic content of n-3 PUFA, with a consequent decrease on the n-6/n-3 ratio. In conclusion, the use of C. vulgaris as feed ingredient appears to be safe under controlled experimental conditions. However, it is imperative test it in industrial production systems, with more stressful and less hygienic environments.


Assuntos
Chlorella vulgaris , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Suplementos Nutricionais , Glicosídeo Hidrolases , Nível de Saúde , Metabolismo dos Lipídeos , Fígado/metabolismo , Suínos
9.
Antonie Van Leeuwenhoek ; 98(3): 331-42, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20422287

RESUMO

Yeasts are common inhabitants of different types of aquatic habitats, including marine and estuarine waters and rivers. Although numerous studies have surveyed yeast occurrence in these habitats, the identification of autochthonous populations has been problematic because several yeast species seem to be very versatile and therefore mere presence is not sufficient to establish an ecological association. In the present study we investigated the dynamics of the yeast community in the Tagus river estuary (Portugal) by combining a microbiological study involving isolation, quantification, and molecular identification of dominant yeast populations with the analysis of hydrological and hydrographical data. We set out to test the hypothesis of the multiple origins of estuarine yeast populations in a transect of the Tagus estuary and we postulate four possible sources: open sea, terrestrial, gastrointestinal and the estuary itself in the case of populations that have become resident. Candida parapsilosis and Pichia guilliermondii were correlated with Escherichia coli, which indicated an intestinal origin. Other cream-colored yeasts like Debaryomyces hansenii and Candida zeylanoides had similar dynamics, but no association with E. coli and quite distinct ecological preferences. They might represent a group of resident estuarine populations whose primary origin is diverse and can include marine, terrestrial, and gastrointestinal habitats. Another major yeast population was represented by Rhodotorula mucilaginosa. The cosmopolitan nature of that species and its moderate association with E. coli point to terrestrial sources as primary habitats.


Assuntos
Ecossistema , Água Doce/microbiologia , Rios/microbiologia , Água do Mar/microbiologia , Microbiologia da Água , Leveduras/classificação , Leveduras/isolamento & purificação , Ascomicetos/classificação , Ascomicetos/isolamento & purificação , Basidiomycota/classificação , Basidiomycota/isolamento & purificação , Biodiversidade , Candida/classificação , Candida/isolamento & purificação , Contagem de Colônia Microbiana , Impressões Digitais de DNA , DNA Fúngico/análise , DNA Ribossômico/análise , Escherichia coli/isolamento & purificação , Oceanos e Mares , Pichia/classificação , Pichia/isolamento & purificação , Reação em Cadeia da Polimerase , Portugal , Rhodotorula/isolamento & purificação
10.
Animals (Basel) ; 10(12)2020 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-33322745

RESUMO

The influence of a high inclusion level of Chlorella vulgaris, individually and supplemented with two carbohydrase mixtures, in finishing pig diets was assessed on zootechnical performance, carcass characteristics, pork quality traits and nutritional value of pork fat. Forty crossbred entire male pigs, sons of Large White × Landrace sows crossed with Pietrain boars, with an initial live weight of 59.1 ± 5.69 kg were used in this trial. Swines were randomly assigned to one of four dietary treatments (n = 10): cereal and soybean meal-based diet (control), control diet with 5% C. vulgaris (CV), CV diet supplemented with 0.005% Rovabio® Excel AP (CV + R) and CV diet supplemented with 0.01% of a four-CAZyme mixture (CV + M). Animals were slaughtered, after the finishing period, with a BW of 101 ± 1.9 kg. Growth performance, carcass characteristics and meat quality traits were not influenced (p > 0.05) by the incorporation of C. vulgaris in the diets. However, the inclusion of the microalga in finishing pig diets increased some lipid-soluble antioxidant pigments and n-3 PUFA, and decreased the n-6:n-3 ratio of fatty acids, thus ameliorating the nutritional value of pork fat. Moreover, the supplementation of diets with the carbohydrase mixtures did not change (p > 0.05) neither animal performance nor meat quality traits, indicating their inefficacy in the increase of digestive utilization of C. vulgaris by pigs under these experimental conditions. It is concluded that the use of C. vulgaris in finishing pig diets, at this high incorporation level, improves the nutritional value of pork fat without compromising pig performance.

11.
Meat Sci ; 160: 107945, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31627117

RESUMO

Thirty-six lambs were used to evaluate the effect of three levels of Cistus ladanifer condensed tannins (CT; 0, 1.25 and 2.5%) and two ways of CT supply (C. ladanifer aerial parts and C. ladanifer CT extract) on lamb growth performance, carcass composition, meat quality and FA composition of intramuscular and subcutaneous fat. The basal diet was composed of dehydrated lucerne supplemented with 60 g/kg of soybean oil. The highest amount of CT (2.5%) had detrimental effects on growth performance, particularly when the aerial part of C. ladanifer was used. Conversely, 1.25% CT in diets did not affect growth performance and meat quality, and inclusion of C. ladanifer CT extract in diet at this level increased t11-18:1, but not c9,t11-18:2 content in fat. Feeding C. ladanifer CT extract might be a good approach for enhancing the nutritional value of ruminant fat, but further studies are needed to ensure upregulation of endogenous synthesis of c9,t11-18:2.


Assuntos
Cistus , Dieta/veterinária , Carne Vermelha/análise , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Ácidos Graxos/análise , Masculino , Componentes Aéreos da Planta , Extratos Vegetais , Proantocianidinas , Carneiro Doméstico/crescimento & desenvolvimento
12.
Meat Sci ; 161: 107964, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31683223

RESUMO

Thirty-two crossbred Merino branco male lambs were randomly allocated to eight diets, combining two forms of alfalfa presentation (chopped or ground), with four barley grain levels (0%, 11.2%, 21.3% and 33% dry matter (DM)), balanced by low starch agro-industrial by-products (LSBP). The diets were supplemented with 6% soybean oil and included 40% of alfalfa in DM. The lambs were individually housed and the trial lasted six weeks. Intake of DM, average daily weight gain (ADG) and carcass weight were higher with ground alfalfa (P < 0.01). Replacing barley grain by LSBP reduced linearly DM intake and ADG (P < 0.001) but increased meat tenderness (P = 0.046). Regardless of the treatments, meat showed a healthy biohydrogenation fatty acid (FA) profile, with high proportions of t11-18:1, c9,t11-18:2 and a t10-18:1/t11-18:1 ratio clearly below 1. The reduction of barley in diet had a moderate positive impact on meat FA composition, decreasing t10-18:1, which was enhanced by the increase of forage particle size.


Assuntos
Ração Animal/análise , Comportamento Alimentar/fisiologia , Qualidade dos Alimentos , Medicago sativa/química , Tamanho da Partícula , Rúmen/fisiologia , Amido/administração & dosagem , Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Animais , Comportamento Animal/fisiologia , Dieta/métodos , Masculino , Carne Vermelha , Ovinos
13.
Animals (Basel) ; 10(10)2020 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-32998259

RESUMO

Surgical castration of piglets without pain relief is still common practice in many countries. Possible alternatives for surgical castration are application of pain relief or anaesthesia or production of boars (entire males) and immunocastrates. Each of these alternatives faces advantages and disadvantages which may result in different citizen attitudes and consumers acceptability. Understanding which practice is acceptable to whom and why may further stimulate implementation. Consumer (n = 3251) and stakeholder (n = 1027) attitudes towards surgical castration without pain relief, surgical castration with anaesthesia, immunocastration, and production of boars were surveyed from April to June 2020 via an online questionnaire in 16 countries (>175 respondents per country). Surgical castration without pain relief was separated from each of the alternatives due to animal welfare and showed the lowest acceptability (32%). Within the alternatives, a further partitioning between the alternatives was based on perceived quality and food safety, with an acceptance of 85% for applying anaesthesia, 71% for immunocastration, and 49% for boar production. Differences depending on professional involvement and familiarity with agriculture could be observed, mainly for the acceptance of surgical castration without anaesthesia, immunocastration, and boars. Castration with anaesthesia was highly accepted by all types of respondents.

16.
ChemSusChem ; 9(24): 3387-3392, 2016 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-27981784

RESUMO

Green, inexpensive, and robust copper-based heterogeneous catalysts achieve 100 % conversion and 99 % selectivity in the conversion of furfural to furfuryl alcohol when using cyclopentyl-methyl ether as green solvent and microwave reactors at low H2 pressures and mild temperatures. The utilization of pressurized microwave reactors produces a 3-4 fold increase in conversion and an unexpected enhancement in selectivity as compared to the reaction carried out at the same conditions using conventional autoclave reactors. The enhancement in catalytic rate produced by microwave irradiation is temperature dependent. This work highlights that using microwave irradiation in the catalytic hydrogenation of biomass-derived compounds is a very strong tool for biomass upgrade that offers immense potential in a large number of transformations where it could be a determining factor for commercial exploitation.


Assuntos
Cobre/química , Furaldeído/química , Furanos/química , Química Verde , Micro-Ondas , Catálise , Hidrogenação
17.
FEMS Microbiol Ecol ; 53(2): 295-303, 2005 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-16329949

RESUMO

The yeast community in the waters of the Tagus estuary, Portugal, was followed for over a year in order to assess its dynamics. Yeast occurrence and incidence were measured and this information was related to relevant environmental data. Yeast occurrence did not seem to depend upon tides, but river discharge had a dramatic impact both on the density and diversity of the community. The occurrence of some yeasts was partially correlated with faecal pollution indicators. Yeast isolates were characterized by microsatellite primed PCR (MSP-PCR) fingerprinting and rRNA gene sequencing. The principal species found were Candida catenulata, C. intermedia, C. parapsilosis, Clavispora lusitaniae, Debaryomyces hansenii, Pichia guilliermondii, Rhodotorula mucilaginosa and Rhodosporidium diobovatum. The incidence of these species was evaluated against the environmental context of the samples and the current knowledge about the substrates from which they are usually isolated.


Assuntos
Microbiologia da Água , Leveduras , Classificação , Impressões Digitais de DNA , DNA Fúngico/análise , Monitoramento Ambiental , Reação em Cadeia da Polimerase , Dinâmica Populacional , Portugal , RNA Ribossômico/análise
18.
Genome Announc ; 3(3)2015 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-25999568

RESUMO

We report the genome sequencing and annotation of the basidiomycetous red-pigmented yeast Sporidiobolus salmonicolor strain CBS 6832. The current assembly contains 395 scaffolds, for a total size of about 20.5 Mb and a G+C content of ~61.3%. The genome annotation predicts 5,147 putative protein-coding genes.

19.
mBio ; 6(1)2015 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-25587012

RESUMO

UNLABELLED: Pneumocystis species are fungal parasites of mammal lungs showing host specificity. Pneumocystis jirovecii colonizes humans and causes severe pneumonia in immunosuppressed individuals. In the absence of in vitro cultures, the life cycle of these fungi remains poorly known. Sexual reproduction probably occurs, but the system of this process and the mating type (MAT) genes involved are not characterized. In the present study, we used comparative genomics to investigate the issue in P. jirovecii and Pneumocystis carinii, the species infecting rats, as well as in their relative Taphrina deformans. We searched sex-related genes using 103 sequences from the relative Schizosaccharomyces pombe as queries. Genes homologous to several sex-related role categories were identified in all species investigated, further supporting sexuality in these organisms. Extensive in silico searches identified only three putative MAT genes in each species investigated (matMc, matMi, and matPi). In P. jirovecii, these genes clustered on the same contig, proving their contiguity in the genome. This organization seems compatible neither with heterothallism, because two different MAT loci on separate DNA molecules would have been detected, nor with secondary homothallism, because the latter involves generally more MAT genes. Consistently, we did not detect cis-acting sequences for mating type switching in secondary homothallism, and PCR revealed identical MAT genes in P. jirovecii isolates from six patients. A strong synteny of the genomic region surrounding the putative MAT genes exists between the two Pneumocystis species. Our results suggest the hypothesis that primary homothallism is the system of reproduction of Pneumocystis species and T. deformans. IMPORTANCE: Sexual reproduction among fungi can involve a single partner (homothallism) or two compatible partners (heterothallism). We investigated the issue in three pathogenic fungal relatives: Pneumocystis jirovecii, which causes severe pneumonia in immunocompromised humans; Pneumocystis carinii, which infects rats; and the plant pathogen Taphrina deformans. The nature, the number, and the organization within the genome of the genes involved in sexual reproduction were determined. The three species appeared to harbor a single genomic region gathering only three genes involved in sexual differentiation, an organization which is compatible with sexual reproduction involving a single partner. These findings illuminate the strategy adopted by fungal pathogens to infect their hosts.


Assuntos
Pneumocystis/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Genes Fúngicos Tipo Acasalamento , Genoma Fúngico , Genômica , Humanos , Pneumocystis/química , Pneumocystis/fisiologia , Infecções por Pneumocystis/microbiologia , Sintenia
20.
Genetics ; 201(1): 75-89, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26178967

RESUMO

In most fungi, sexual reproduction is bipolar; that is, two alternate sets of genes at a single mating-type (MAT) locus determine two mating types. However, in the Basidiomycota, a unique (tetrapolar) reproductive system emerged in which sexual identity is governed by two unlinked MAT loci, each of which controls independent mechanisms of self/nonself recognition. Tetrapolar-to-bipolar transitions have occurred on multiple occasions in the Basidiomycota, resulting, for example, from linkage of the two MAT loci into a single inheritable unit. Nevertheless, owing to the scarcity of molecular data regarding tetrapolar systems in the earliest-branching lineage of the Basidiomycota (subphylum Pucciniomycotina), it is presently unclear if the last common ancestor was tetrapolar or bipolar. Here, we address this question, by investigating the mating system of the Pucciniomycotina yeast Leucosporidium scottii. Using whole-genome sequencing and chromoblot analysis, we discovered that sexual reproduction is governed by two physically unlinked gene clusters: a multiallelic homeodomain (HD) locus and a pheromone/receptor (P/R) locus that is biallelic, thereby dismissing the existence of a third P/R allele as proposed earlier. Allele distribution of both MAT genes in natural populations showed that the two loci were in strong linkage disequilibrium, but independent assortment of MAT alleles was observed in the meiotic progeny of a test cross. The sexual cycle produces fertile progeny with similar proportions of the four mating types, but approximately 2/3 of the progeny was found to be nonhaploid. Our study adds to others in reinforcing tetrapolarity as the ancestral state of all basidiomycetes.


Assuntos
Basidiomycota/fisiologia , Genes Fúngicos Tipo Acasalamento , Basidiomycota/genética , Evolução Molecular , Genoma Fúngico , Haploidia , Desequilíbrio de Ligação , Filogenia , Análise de Sequência de DNA
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