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排序方式: 共有206条查询结果,搜索用时 15 毫秒
121.
Erik Volz Verity Hill John T. McCrone Anna Price David Jorgensen Áine O’Toole Joel Southgate Robert Johnson Ben Jackson Fabricia F. Nascimento Sara M. Rey Samuel M. Nicholls Rachel M. Colquhoun Ana da Silva Filipe James Shepherd David J. Pascall Rajiv Shah Natasha Jesudason Thomas R. Connor 《Cell》2021,184(1):64-75.e11
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122.
Hoeijmakers WA Flueck C Françoijs KJ Smits AH Wetzel J Volz JC Cowman AF Voss T Stunnenberg HG Bártfai R 《Cellular microbiology》2012,14(9):1391-1401
Centromeres are essential for the faithful transmission of chromosomes to the next generation, therefore being essential in all eukaryotic organisms. The centromeres of Plasmodium falciparum, the causative agent of the most severe form of malaria, have been broadly mapped on most chromosomes, but their epigenetic composition remained undefined. Here, we reveal that the centromeric histone variant PfCENH3 occupies a 4–4.5 kb region on each P. falciparum chromosome, which is devoid of pericentric heterochromatin but harbours another histone variant, PfH2A.Z. These CENH3 covered regions pinpoint the exact position of the centromere on all chromosomes and revealed that all centromeric regions have similar size and sequence composition. Immunofluorescence assay of PfCENH3 strongly suggests that P. falciparum centromerescluster to a single nuclear location prior to and during mitosis and cytokinesis but dissociate soon after invasion. In summary, we reveal a dynamic association of Plasmodium centromeres, which bear a unique epigenetic signature and conform to a strict structure. These findings suggest that DNA‐associated and epigenetic elements play an important role in centromere establishment in this important human pathogen. 相似文献
123.
Nuclear behavior during ascus development inChaetomium globosum was studied with the use of acetocarmine and aceto-orcein staining techniques. The chromosome behavior, including centriolar bodies and asynchronous disjunction of chromosomes, agreed with the basic pattern reported in Ascomycetes (Olive, 1965). The haploid chromosome complement of this strain appeared to be 6. 相似文献
124.
Summary Compatible strains of Schizophyllum commune Fr. were grown on a minimal medium with adjustments in the CO2 level and the carbon source. Acetate with glucose initiated reduced stipes and pilei of fruit-bodies, and changed lamellar cell structure. Sealed growth chambers increased CO2 levels and inhibited basidiocarp formation while growth of dense hyphal aggregates in the dikaryotic mycelium was stimulated. 相似文献
125.
Summary Sclerotia of Coprinus lagopus were produced in the laboratory and observed microscopically from initiation to maturity. Isolated bulbous hyphal cells appeared below or on the agar surface as the primary sclerotial initials. Short interhyphal cells had expanded lateral walls and increased in number at their isolated locations, and were surrounded by a thick network of normal mycelium. Increasing in numbers, the bulbous cells developed a tightly compact colony devoid of agar if submerged below the agar surface and lacked normal hyphal filaments. The outer cells thickened formed cell lumina and developed as a protective rind to the mature sclerotium. 相似文献
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128.
Erik M. Volz Edward Ionides Ethan O. Romero-Severson Mary-Grace Brandt Eve Mokotoff James S. Koopman 《PLoS medicine》2013,10(12)
Background
Conventional epidemiological surveillance of infectious diseases is focused on characterization of incident infections and estimation of the number of prevalent infections. Advances in methods for the analysis of the population-level genetic variation of viruses can potentially provide information about donors, not just recipients, of infection. Genetic sequences from many viruses are increasingly abundant, especially HIV, which is routinely sequenced for surveillance of drug resistance mutations. We conducted a phylodynamic analysis of HIV genetic sequence data and surveillance data from a US population of men who have sex with men (MSM) and estimated incidence and transmission rates by stage of infection.Methods and Findings
We analyzed 662 HIV-1 subtype B sequences collected between October 14, 2004, and February 24, 2012, from MSM in the Detroit metropolitan area, Michigan. These sequences were cross-referenced with a database of 30,200 patients diagnosed with HIV infection in the state of Michigan, which includes clinical information that is informative about the recency of infection at the time of diagnosis. These data were analyzed using recently developed population genetic methods that have enabled the estimation of transmission rates from the population-level genetic diversity of the virus. We found that genetic data are highly informative about HIV donors in ways that standard surveillance data are not. Genetic data are especially informative about the stage of infection of donors at the point of transmission. We estimate that 44.7% (95% CI, 42.2%–46.4%) of transmissions occur during the first year of infection.Conclusions
In this study, almost half of transmissions occurred within the first year of HIV infection in MSM. Our conclusions may be sensitive to un-modeled intra-host evolutionary dynamics, un-modeled sexual risk behavior, and uncertainty in the stage of infected hosts at the time of sampling. The intensity of transmission during early infection may have significance for public health interventions based on early treatment of newly diagnosed individuals. Please see later in the article for the Editors'' Summary 相似文献129.
Myriam Mirza Cornelia Volz Marcus Karlstetter Monica Langiu Aleksandra Somogyi Mika O. Ruonala Ernst R. Tamm Herbert J?gle Thomas Langmann 《PloS one》2013,8(10)
Neuronal ceroid lipofuscinosis (NCL) is a group of neurodegenerative lysosomal storage disorders characterized by vision loss, mental and motor deficits, and spontaneous seizures. Neuropathological analyses of autopsy material from NCL patients and animal models revealed brain atrophy closely associated with glial activity. Earlier reports also noticed loss of retinal cells and reactive gliosis in some forms of NCL. To study this phenomenon in detail, we analyzed the ocular phenotype of CLN6nclf mice, an established mouse model for variant-late infantile NCL. Retinal morphometry, immunohistochemistry, optokinetic tracking, electroretinography, and mRNA expression were used to characterize retinal morphology and function as well as the responses of Müller cells and microglia. Our histological data showed a severe and progressive degeneration in the CLN6nclf retina co-inciding with reactive Müller glia. Furthermore, a prominent phenotypic transformation of ramified microglia to phagocytic, bloated, and mislocalized microglial cells was identified in CLN6nclf retinas. These events overlapped with a rapid loss of visual perception and retinal function. Based on the strong microglia reactivity we hypothesized that dietary supplementation with immuno-regulatory compounds, curcumin and docosahexaenoic acid (DHA), could ameliorate microgliosis and reduce retinal degeneration. Our analyses showed that treatment of three-week-old CLN6nclf mice with either 5% DHA or 0.6% curcumin for 30 weeks resulted in a reduced number of amoeboid reactive microglia and partially improved retinal function. DHA-treatment also improved the morphology of CLN6nclf retinas with a preserved thickness of the photoreceptor layer in most regions of the retina. Our results suggest that microglial reactivity closely accompanies disease progression in the CLN6nclf retina and both processes can be attenuated with dietary supplemented immuno-modulating compounds. 相似文献
130.