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The phytophagous fruit fly Rhagoletis meigenii harbors the bacterium Wolbachia pipientis and, together with Japanese barberry, form a tri-partite symbiosis. R. meigenii is a seed predator of invasive Japanese barberry plants and is dependent on this insect-plant interaction for reproductive success. The endosymbiotic bacterium W. pipientis is a reproductive parasite known to alter the sex ratios of offspring and the fitness of infected host insects. We investigated Japanese barberry fruit for the degree of infestation by R. meigenii and characterized the Wolbachia strain infecting R. meigenii. Densities of R. meigenii in four naturalized stands of Japanese barberry revealed low numbers of fruit flies with high variability in the population densities observed among individual plants. Overall, R. meigenii infested roughly 10–20 % of the Japanese barberry fruits analyzed; fruit with two seeds (vs. one seed) were the most frequently infested. Approximately, 90 % of the R. meigenii tested positive for Wolbachia infection via PCR amplification of the Wolbachia surface protein (wsp) gene. No bacterial strain diversity was observed when comparing multi-locus sequence typing (MLST) profiles within or among five R. meigenii populations in Maine, although the MLST profile obtained from R. meigenii differed from three co-occurring Rhagoletis. The Wolbachia endosymbiont of R. meigenii is a member of the Wolbachia supergroup A and the ST-13 cluster complex. 相似文献
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Alex Graça Contato Vanessa Kaplum Débora Botura Scariot Francielle Pelegrin Garcia Hugo Falzirolli Fábio Vandresen Tânia Ueda-Nakamura Sueli de Oliveira Silva Cleuza Conceição da Silva Celso Vataru Nakamura 《化学与生物多样性》2023,20(7):e202300523
Leishmaniasis is a tropical zoonotic disease. It is found in 98 countries, with an estimated 1.3 million people being affected annually. During the life cycle, the Leishmania parasite alternates between promastigote and amastigote forms. The first line treatment for leishmaniasis are the pentavalent antimonials, such as N-methylglucamine antimoniate (Glucantime®) and sodium stibogluconate (Pentostam®). These drugs are commonly related to be associated with dangerous side effects such as cardiotoxicity, nephrotoxicity, hepatotoxicity, and pancreatitis. Considering these aspects, this work aimed to obtain a new series of limonene-acylthiosemicarbazides hybrids as an alternative for the treatment of leishmaniasis. For this, promastigotes, axenic amastigotes, and intracellular amastigotes of Leishmania amazonensis were used in the antiproliferative assay; J774-A1 macrophages for the cytotoxicity assay; and electron microscopy techniques were performed to analyze the morphology and ultrastructure of parasites. ATZ−S-04 compound showed the best result in both tests. Its IC50, in promastigotes, axenic amastigotes and intracellular amastigotes was 0.35±0.08 μM, 0.49±0.06 μM, and 15.90±2.88 μM, respectively. Cytotoxicity assay determined a CC50 of 16.10±1.76 μM for the same compound. By electron microscopy, it was observed that ATZ−S-04 affected mainly the Golgi complex, in addition to morphological changes in promastigote forms of L. amazonensis. 相似文献
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Marcelo U. Ferreira Isabel Giacomini Priscila M. Sato Barbara H. Loureno Vanessa C. Nicolete Lewis F. Buss Alicia Matijasevich Marcia C. Castro Marly A. Cardoso for the MINA-Brazil Working Group 《PLoS neglected tropical diseases》2022,16(7)
BackgroundThe epidemiology of childhood SARS-CoV-2 infection and COVID-19-related illness remains little studied in high-transmission tropical settings, partly due to the less severe clinical manifestations typically developed by children and the limited availability of diagnostic tests. To address this knowledge gap, we investigate the prevalence and predictors of SARS-CoV-2 infection (either symptomatic or not) and disease in 5 years-old Amazonian children.Methodology/Principal findingsWe retrospectively estimated SARS-CoV-2 attack rates and the proportion of infections leading to COVID-19-related illness among 660 participants in a population-based birth cohort study in the Juruá Valley, Amazonian Brazil. Children were physically examined, tested for SARS-CoV-2 IgG and IgM antibodies, and had a comprehensive health questionnaire administered during a follow-up visit at the age of 5 years carried out in January or June-July 2021. We found serological evidence of past SARS-CoV-2 infection in 297 (45.0%; 95% confidence interval [CI], 41.2–48.9%) of 660 cohort participants, but only 15 (5.1%; 95% CI, 2.9–8.2%) seropositive children had a prior medical diagnosis of COVID-19 reported by their mothers or guardians. The period prevalence of clinically apparent COVID-19, defined as the presence of specific antibodies plus one or more clinical symptoms suggestive of COVID-19 (cough, shortness of breath, and loss of taste or smell) reported by their mothers or guardians since the pandemic onset, was estimated at 7.3% (95% CI, 5.4–9.5%). Importantly, children from the poorest households and those with less educated mothers were significantly more likely to be seropositive, after controlling for potential confounders by mixed-effects multiple Poisson regression analysis. Likewise, the period prevalence of COVID-19 was 1.8-fold (95%, CI 1.2–2.6-fold) higher among cohort participants exposed to food insecurity and 3.0-fold (95% CI, 2.8–3.5-fold) higher among those born to non-White mothers. Finally, children exposed to household and family contacts who had COVID-19 were at an increased risk of being SARS-CoV-2 seropositive and–even more markedly–of having had clinically apparent COVID-19 by the age of 5 years.Conclusions/SignificanceChildhood SARS-CoV-2 infection and COVID-19-associated illness are substantially underdiagnosed and underreported in the Amazon. Children in the most socioeconomically vulnerable households are disproportionately affected by SARS-CoV-2 infection and disease. 相似文献
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Vanessa Meier-Stephenson 《Biophysical reviews》2022,14(3):635
There are over 700,000 putative G4-quadruplexes (G4Qs) in the human genome, found largely in promoter regions, telomeres, and other regions of high regulation. Growing evidence links their presence to functionality in various cellular processes, where cellular proteins interact with them, either stabilizing and/or anchoring upon them, or unwinding them to allow a process to proceed. Interest in understanding and manipulating the plethora of processes regulated by these G4Qs has spawned a new area of small-molecule binder development, with attempts to mimic and block the associated G4-binding protein (G4BP). Despite the growing interest and focus on these G4Qs, there is limited data (in particular, high-resolution structural information), on the nature of these G4Q-G4BP interactions and what makes a G4BP selective to certain G4Qs, if in fact they are at all. This review summarizes the current literature on G4BPs with regards to their interactions with G4Qs, providing groupings for binding mode, drawing conclusions around commonalities and highlighting information on specific interactions where available. 相似文献
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Jindong Zhang Vanessa Hull Zhiyun Ouyang Liang He Thomas Connor Hongbo Yang Jinyan Huang Shiqiang Zhou Zejun Zhang Caiquan Zhou Hemin Zhang Jianguo Liu 《Ecology and evolution》2017,7(8):2575-2584
The study of wildlife activity patterns is an effective approach to understanding fundamental ecological and evolutionary processes. However, traditional statistical approaches used to conduct quantitative analysis have thus far had limited success in revealing underlying mechanisms driving activity patterns. Here, we combine wavelet analysis, a type of frequency‐based time‐series analysis, with high‐resolution activity data from accelerometers embedded in GPS collars to explore the effects of internal states (e.g., pregnancy) and external factors (e.g., seasonal dynamics of resources and weather) on activity patterns of the endangered giant panda (Ailuropoda melanoleuca). Giant pandas exhibited higher frequency cycles during the winter when resources (e.g., water and forage) were relatively poor, as well as during spring, which includes the giant panda's mating season. During the summer and autumn when resources were abundant, pandas exhibited a regular activity pattern with activity peaks every 24 hr. A pregnant individual showed distinct differences in her activity pattern from other giant pandas for several months following parturition. These results indicate that animals adjust activity cycles to adapt to seasonal variation of the resources and unique physiological periods. Wavelet coherency analysis also verified the synchronization of giant panda activity level with air temperature and solar radiation at the 24‐hr band. Our study also shows that wavelet analysis is an effective tool for analyzing high‐resolution activity pattern data and its relationship to internal and external states, an approach that has the potential to inform wildlife conservation and management across species. 相似文献
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Michael D. Weiser Sean T. Michaletz Vanessa Buzzard Ye Deng Zhili He Lina Shen Brian J. Enquist Robert B. Waide Jizhong Zhou Michael Kaspari 《Ecography》2018,41(2):255-264
The abundance–adaptation hypothesis argues that taxa with more individuals and faster generation times will have more evolutionary ‘experiments’ allowing expansion into, and diversification within, novel habitats. Thus, as older taxa have produced more individuals over time, and smaller taxa have higher population sizes and faster generation times, the Latitudinal Diversity Gradients (LDGs) of these clades should show shallower slopes. We describe the LDGs for archaea, bacteria, fungi, invertebrates and trees from six North American forests. For three focal groups – bacteria, ants, and trees – older taxa had shallower LDG slopes than the more recent, terminal taxa. Across 12 orders of magnitude of body mass, LDG slopes were steeper in larger taxa. The slopes of LDGs vary systematically with body size and clade age, underscoring the non‐canonical nature of LDGs. The steepest LDG slopes were found for the largest organisms while the smallest, from bacteria to small litter‐soil invertebrates, have shallower‐ to zero‐slope LDGs. If tropical niche conservatism is the failure of clades to adapt to, and diversify in temperate habitats, then the steep LDGs of chordates and plants likely arise from the decreased ability of clades with large individuals to adapt to the multiple challenges of extra‐tropical life. 相似文献
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Vanessa B. Fortes Júlio César Bicca-Marques 《International journal of primatology》2008,29(3):717-722
We located 4 brown howlers (1 adult male, 2 adult females, and 1 juvenile male) showing abnormally lighter pelage in 3 social
groups comprising 5, 6, and 9 individuals in a 20 ha-forest fragment in the State of Rio Grande do Sul, Brazil. Two additional
groups composed only of normally colored individuals also live in the fragment, which is isolated from nearby fragments by
267–1009 m. They were the only brown howlers with abnormal pelage color out of a total of 386 individuals belonging to 67
groups in 21 fragments in the 5876-ha study area. The isolation of the forest fragment, its high howler density (2.2 individuals⁄ha),
and large group size (8.8 ± 2.4 individuals) may decrease the likelihood of successful immigration into the population, leading
to an increased probability of inbreeding that may facilitate the expression of rare alleles. 相似文献
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