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1.
Mol Biol Evol ; 39(5)2022 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-35588244

RESUMO

Accessory genes are variably present among members of a species and are a reservoir of adaptive functions. In bacteria, differences in gene distributions among individuals largely result from mobile elements that acquire and disperse accessory genes as cargo. In contrast, the impact of cargo-carrying elements on eukaryotic evolution remains largely unknown. Here, we show that variation in genome content within multiple fungal species is facilitated by Starships, a newly discovered group of massive mobile elements that are 110 kb long on average, share conserved components, and carry diverse arrays of accessory genes. We identified hundreds of Starship-like regions across every major class of filamentous Ascomycetes, including 28 distinct Starships that range from 27 to 393 kb and last shared a common ancestor ca. 400 Ma. Using new long-read assemblies of the plant pathogen Macrophomina phaseolina, we characterize four additional Starships whose activities contribute to standing variation in genome structure and content. One of these elements, Voyager, inserts into 5S rDNA and contains a candidate virulence factor whose increasing copy number has contrasting associations with pathogenic and saprophytic growth, suggesting Voyager's activity underlies an ecological trade-off. We propose that Starships are eukaryotic analogs of bacterial integrative and conjugative elements based on parallels between their conserved components and may therefore represent the first dedicated agents of active gene transfer in eukaryotes. Our results suggest that Starships have shaped the content and structure of fungal genomes for millions of years and reveal a new concerted route for evolution throughout an entire eukaryotic phylum.


Assuntos
Genoma Fúngico , Fatores de Virulência , Elementos de DNA Transponíveis , Células Eucarióticas , Humanos
2.
Plant Dis ; 107(2): 401-412, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35787008

RESUMO

Heterodera glycines, the soybean cyst nematode (SCN), and fungal pathogen Macrophomina phaseolina are economically important soybean pathogens that may coinfest fields. Resistance remains the most effective management tactic for SCN, and the rhg1-b resistance allele derived from plant introduction 88788 is most commonly deployed in the northern United States. The concomitant effects of SCN and M. phaseolina on soybean performance, as well as the effect of the rhg1-b allele in two different genetic backgrounds, were evaluated in three environments (during 2013 to 2015) and a greenhouse bioassay. Within two soybean populations, half of the lines had the rhg1-b allele, and the other half had the susceptible allele in the backgrounds of the cultivars IA3023 and LD00-3309. Significant interactions between soybean rhg1-b allele and M. phaseolina-infested plots were observed in 2014. In all experiments, initial SCN populations (Pi) and M. phaseolina in roots were associated with reduced soybean yield. SCN reproduction factor (RF = final population/Pi) was affected by SCN Pi, rhg1-b, and genetic background. A background-by-genotype interaction on yield was observed only in 2015, with a stronger rhg1-b effect in the LD00-3309 background, which suggested that the susceptible parent 'IA3023' is tolerant to SCN. SCN female index from greenhouse experiments was compared with field RF, and Lin's concordance and Pearson's correlation coefficients decreased with increasing field SCN Pi in soil. In this study, both SCN and M. phaseolina reduced soybean yield asymptomatically, and the impact of SCN rhg1-b resistance was dependent on SCN virulence but also population density.


Assuntos
Glycine max , Tylenchoidea , Animais , Glycine max/genética , Doenças das Plantas/microbiologia , Genótipo , Tylenchoidea/genética
3.
Plant Dis ; 2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33728964

RESUMO

Japanese apple rust, caused by the heteroecious and demicyclic rust fungus Gymnosporangium yamadae Miyabe ex G. Yamada, can affect juniper (Juniperus spp.), where the telial stage of this disease occurs, and apple or crabapple (Malus spp.), where the aecial stage occurs (Yun, 2010). Leaf samples displaying symptoms and signs of rust disease were collected in August 2020 from 14 different crabapple cultivars ('Amerspirzam' [American Spirit®], 'Amsalzam' [American Salute™], 'Excazam' [Excalibur™], 'Guinzam' [Guinevere®], 'Hargozam' [Harvest Gold®], 'Mary Potter', 'Orange Crush', 'Prairie Maid', 'Professor Sprenger', 'Pumpkin Pie', 'Rawhide', 'Select A' [Firebird®], 'Shotizam' [Show Time™], 'Sinai Fire') in the crabapple research plot of Secrest Arboretum (Crablandia) in Wooster, OH. Samples displayed adaxial leaf lesions with brown necrotic centers surrounded by a red-yellow coloration, corresponding on the abaxial side to lesions containing brown-orange aecia, producing aeciospores, surrounded by a dark red-orange coloration (Supplemental Figure 1). One to multiple lesions were present per symptomatic leaf. DNA was extracted from symptomatic leaf tissue containing fungal material on all 14 cultivars using the DNeasy Plant Mini Kit (QIagen) and the D1/D2 region of the 28S rDNA was amplified using primers NL1 and NL4 (O'Donnell 1993) according to Dagar et al. (2011). GenBank BLAST sequence analysis of all 14 sequences resulted in 99.83-100% sequence identity to G. yamadae with with 99% query coverage (MN605735). Sequences from all samples were deposited in GenBank under Accession Nos. MW131119.2-131125.2 and MW131127.2-131132.2. Morphological features were characterized for the three representative cultivars 'Amerspirzam' (American Spirit®), 'Orange Crush' and 'Pumpkin Pie' (Supplemental Figure 2). Aecia were hypophyllous, roestelioid, with cornute, yellow-brown, peridia with lacerate sides. Peridial cells appeared yellow and were long-linear rhomboid, verrucose with long papillae, smooth outer walls and echinulate inner walls, measuring 45 - 78 × 16 - 27 µm (average 65 × 21 µm), 51 - 82 × 16 - 30 µm (average 66 × 23 µm), and 47 - 93 × 14 - 31 µm (average 64 × 24 µm), respectively (n=50 per cultivar). Aeciospores were globose, 20 - 26 × 18 - 24 µm (average 23 µm × 20 µm), 21 - 28 µm × 19 - 24 µm (average 24 µm × 21 µm), and 21 - 27 µm × 18 - 23 µm (average 23 µm × 21 µm), respectively, with a slightly coronate surface and dark yellow walls 1.6 - 2.7 µm (average 2 µm), 1.4 - 2.4 µm (average 2 µm), and 1.3 - 2.5 µm (average 1.8 µm) thick, respectively (n=50 per cultivar). The telia, known to occur on Juniperus spp., were not observed. Specimens from these three cultivars were deposited into the U.S. National Fungus Collections (BPI 923889, 923888, 923887). Japanese apple rust has been officially reported in parts of Eastern Asia and the Eastern United States and is also known to be present in parts of Far East Russia and Ontario, Canada (Yun et al., 2009; CAB International, 2008). This report constitutes the first confirmed instance of G. yamadae causing Japanese apple rust in Ohio. Because infected trees tend to be highly symptomatic, this disease poses a significant threat to the nursery and landscape industries as it can decrease the market value of ornamental varieties and affect yield and crop quality in varieties used for fruit production.

4.
Behav Med ; 42(1): 57-62, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-25337949

RESUMO

Postural orthostatic tachycardia syndrome (POTS) is a multifaceted disorder of the autonomic nervous system that profoundly impacts physical functioning. In addition to physical consequences, many patients develop situational anxiety that causes reduced activity level, which may impede functional recovery from POTS. Despite links with anxiety, to date there have been no reports of psychological intervention for POTS. Here we report a case study of POTS in a 40-year-old female serving on active duty in the US military. Because there are no established guidelines for the psychological treatment of POTS, intervention techniques were adapted for use with the patient. Elements of cognitive behavioral therapy, including in-vivo exposure and symptom discrimination, were used to target avoidance of feared situations. Over the course of treatment, the patient learned to discriminate her POTS symptoms from anxiety and displayed a significant decrease in POTS-related functional impairment. Implications for future care are discussed.


Assuntos
Terapia Comportamental/métodos , Síndrome da Taquicardia Postural Ortostática/terapia , Adulto , Ansiedade/fisiopatologia , Ansiedade/psicologia , Pressão Sanguínea/fisiologia , Terapia Cognitivo-Comportamental/métodos , Feminino , Frequência Cardíaca/fisiologia , Humanos , Síndrome da Taquicardia Postural Ortostática/fisiopatologia
5.
Cogn Behav Ther ; 39(4): 262-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21038154

RESUMO

College students with elevated depressive symptoms are more likely to engage in risky drinking and experience alcohol-related negative consequences. Efforts to understand the association between depressed mood and alcohol use have begun to identify the role of cognitive-motivational processes. Drinking refusal self-efficacy is one such process that influences the decision to drink, but its relationship with depressed mood remains unclear. The current study sought to clarify the role of these processes using a depressed mood induction procedure in a sample of college student drinkers. Eighty-six students were randomized to a depressed or neutral mood induction and completed assessments of drinking refusal self-efficacy. Depressed mood significantly decreased self-efficacy in high-risk drinking contexts related to depression, whereas ratings of other high-risk contexts were unaffected. These findings suggest that the association between hazardous drinking and depressed mood may be due in part to the direct influence of mood state on one's self-efficacy to resist drinking in relevant contexts.


Assuntos
Afeto , Consumo de Bebidas Alcoólicas/psicologia , Depressão/psicologia , Autoeficácia , Estudantes/psicologia , Temperança/psicologia , Adolescente , Consumo de Bebidas Alcoólicas/prevenção & controle , Feminino , Humanos , Masculino , Testes Psicológicos , Universidades , Adulto Jovem
6.
Addict Behav ; 38(12): 2810-6, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24018222

RESUMO

BACKGROUND: Research suggests that depressed mood is associated with alcohol-related problems, though its relation with drinking behavior has been inconsistent across studies. Efforts to better understand the link between depressed mood and alcohol use have examined drinking motives as a potentially important moderating variable. The current study sought to examine whether drinking motives moderate the influence of depressed mood on alcohol-related action tendencies. Based on Baker, Morse, and Sherman's (1986) positive and negative reinforcement schema model, two competing moderational hypotheses regarding the influence of depressed mood on appetitive responses for alcohol were tested. METHODS: One hundred and sixty-nine college student drinkers completed assessments of drinking motives and alcohol use. Subjects were exposed to a neutral or depressed mood induction followed by a computerized measure of action tendencies toward alcohol stimuli. RESULTS: Hierarchical regression analyses were conducted to examine whether the influence of depressed mood on action tendencies toward alcohol was moderated by drinking motives. Results showed that there was a significant interaction between mood induction condition and enhancement motives, such that depressed mood appeared to suppress appetitive responding toward alcohol among those with higher enhancement motives. In contrast, there was no evidence that coping motives moderated the association between mood and appetitive response to alcohol. CONCLUSIONS: These results suggest that inhibiting affect states associated with one's motivational disposition for drinking may result in the devaluation of alcohol. Limitations and implications are discussed.


Assuntos
Consumo de Bebidas Alcoólicas/psicologia , Depressão/psicologia , Motivação , Adaptação Psicológica/fisiologia , Afeto/fisiologia , Consumo de Bebidas Alcoólicas/fisiopatologia , Aprendizagem da Esquiva/fisiologia , Sinais (Psicologia) , Depressão/fisiopatologia , Feminino , Humanos , Masculino , Estimulação Luminosa , Tempo de Reação/fisiologia , Adulto Jovem
7.
Drug Alcohol Depend ; 122(1-2): 149-51, 2012 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21968339

RESUMO

BACKGROUND: Depressive symptoms in college students have been associated with a number of indices of hazardous drinking. Investigators have utilized a variety of experimental paradigms to better understand the cognitive-motivational mechanisms that may underlie this association. Implicit cognition studies have provided increasing support for the view that coping motives may moderate the association between negative affect and the incentive value of alcohol. However, less is known about how symptoms of depression may be linked with implicit evaluative responses to alcohol. The current research sought to investigate the association between depressive symptoms and implicit evaluations of alcohol stimuli as measured by an evaluative priming task. METHODS: Eighty-two current drinkers completed assessments of depressive symptoms, alcohol use, and drinking motives before engaging in a computerized alcohol evaluative priming task. RESULTS: Analyses showed that the association between depressive symptoms and the positive implicit evaluation of alcohol was moderated by drinking motives, such that the positive association between depression and alcohol evaluation was stronger for students who had higher coping motives. CONCLUSIONS: These findings add to our understanding of how depressive symptoms may influence responses to alcohol and provide further support for the view that individual differences in coping motives may be a critical moderator of the association between depressive symptoms and alcohol-related cognitive motivational processes.


Assuntos
Adaptação Psicológica , Consumo de Bebidas Alcoólicas/psicologia , Depressão/psicologia , Motivação , Estudantes/psicologia , Adolescente , Feminino , Humanos , Masculino , Fatores de Risco , Universidades , Adulto Jovem
8.
Addict Behav ; 36(11): 1083-6, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21733631

RESUMO

The main objective of the present study was to advance our understanding of how life goals are associated with hazardous alcohol use among first-year university students. One-hundred and seventeen students rated a series of self-generated life goals on meaning and efficacy and then completed alcohol assessments. Higher goal meaning ratings were associated with less alcohol use and fewer heavy drinking episodes. Tests of indirect effects showed that the associations between goal meaning ratings and alcohol use indices were mediated by motives to limit drinking, particularly the motive to maintain self-control/standards. These results replicate and extend previous work on goal meaning and hazardous drinking among students. Findings are consistent with the view that engagement in university life goals may serve as a protective factor against hazardous drinking among first-year students due to greater concern with the impact of drinking on their ability to attain goal standards.


Assuntos
Consumo de Bebidas Alcoólicas/psicologia , Transtornos Relacionados ao Uso de Álcool/psicologia , Objetivos , Motivação , Estudantes/psicologia , Consumo de Bebidas Alcoólicas/epidemiologia , Transtornos Relacionados ao Uso de Álcool/epidemiologia , Estudos Transversais , Humanos , Universidades
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