72 research outputs found

    Immunolocalization of dually phosphorylated MAPKs in dividing root meristem cells of Vicia faba, Pisum sativum, Lupinus luteus and Lycopersicon esculentum

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    Key message In plants, phosphorylated MAPKs display constitutive nuclear localization; however, not all studied plant species show co-localization of activated MAPKs to mitotic microtubules. Abstract The mitogen-activated protein kinase (MAPK) signaling pathway is involved not only in the cellular response to biotic and abiotic stress but also in the regulation of cell cycle and plant development. The role of MAPKs in the formation of a mitotic spindle has been widely studied and the MAPK signaling pathway was found to be indispensable for the unperturbed course of cell division. Here we show cellular localization of activated MAPKs (dually phosphorylated at their TXY motifs) in both interphase and mitotic root meristem cells of Lupinus luteus, Pisum sativum, Vicia faba (Fabaceae) and Lycopersicon esculentum (Solanaceae). Nuclear localization of activated MAPKs has been found in all species. Colocalization of these kinases to mitotic microtubules was most evident in L. esculentum, while only about 50 % of mitotic cells in the root meristems of P. sativum and V. faba displayed activated MAPKs localized to microtubules during mitosis. Unexpectedly, no evident immunofluorescence signals at spindle microtubules and phragmoplast were noted in L. luteus. Considering immunocytochemical analyses and studies on the impact of FR180204 (an inhibitor of animal ERK1/2) on mitotic cells, we hypothesize that MAPKs may not play prominent role in the regulation of microtubule dynamics in all plant species

    Genomic epidemiology reveals multiple introductions of Zika virus into the United States

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    Zika virus (ZIKV) is causing an unprecedented epidemic linked to severe congenital abnormalities. In July 2016, mosquito-borne ZIKV transmission was reported in the continental United States; since then, hundreds of locally acquired infections have been reported in Florida. To gain insights into the timing, source, and likely route(s) of ZIKV introduction, we tracked the virus from its first detection in Florida by sequencing ZIKV genomes from infected patients and Aedes aegypti mosquitoes. We show that at least 4 introductions, but potentially as many as 40, contributed to the outbreak in Florida and that local transmission is likely to have started in the spring of 2016-several months before its initial detection. By analysing surveillance and genetic data, we show that ZIKV moved among transmission zones in Miami. Our analyses show that most introductions were linked to the Caribbean, a finding corroborated by the high incidence rates and traffic volumes from the region into the Miami area. Our study provides an understanding of how ZIKV initiates transmission in new regions

    Ebola virus epidemiology, transmission, and evolution during seven months in Sierra Leone

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    The 2013-2015 Ebola virus disease (EVD) epidemic is caused by the Makona variant of Ebola virus (EBOV). Early in the epidemic, genome sequencing provided insights into virus evolution and transmission and offered important information for outbreak response. Here, we analyze sequences from 232 patients sampled over 7 months in Sierra Leone, along with 86 previously released genomes from earlier in the epidemic. We confirm sustained human-to-human transmission within Sierra Leone and find no evidence for import or export of EBOV across national borders after its initial introduction. Using high-depth replicate sequencing, we observe both host-to-host transmission and recurrent emergence of intrahost genetic variants. We trace the increasing impact of purifying selection in suppressing the accumulation of nonsynonymous mutations over time. Finally, we note changes in the mucin-like domain of EBOV glycoprotein that merit further investigation. These findings clarify the movement of EBOV within the region and describe viral evolution during prolonged human-to-human transmission

    Virus genomes reveal factors that spread and sustained the Ebola epidemic.

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    The 2013-2016 West African epidemic caused by the Ebola virus was of unprecedented magnitude, duration and impact. Here we reconstruct the dispersal, proliferation and decline of Ebola virus throughout the region by analysing 1,610 Ebola virus genomes, which represent over 5% of the known cases. We test the association of geography, climate and demography with viral movement among administrative regions, inferring a classic 'gravity' model, with intense dispersal between larger and closer populations. Despite attenuation of international dispersal after border closures, cross-border transmission had already sown the seeds for an international epidemic, rendering these measures ineffective at curbing the epidemic. We address why the epidemic did not spread into neighbouring countries, showing that these countries were susceptible to substantial outbreaks but at lower risk of introductions. Finally, we reveal that this large epidemic was a heterogeneous and spatially dissociated collection of transmission clusters of varying size, duration and connectivity. These insights will help to inform interventions in future epidemics

    Genome sequencing reveals Zika virus diversity and spread in the Americas

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    Although the recent Zika virus (ZIKV) epidemic in the Americas and its link to birth defects have attracted a great deal of attention, much remains unknown about ZIKV disease epidemiology and ZIKV evolution, in part owing to a lack of genomic data. Here we address this gap in knowledge by using multiple sequencing approaches to generate 110 ZIKV genomes from clinical and mosquito samples from 10 countries and territories, greatly expanding the observed viral genetic diversity from this outbreak. We analysed the timing and patterns of introductions into distinct geographic regions; our phylogenetic evidence suggests rapid expansion of the outbreak in Brazil and multiple introductions of outbreak strains into Puerto Rico, Honduras, Colombia, other Caribbean islands, and the continental United States. We find that ZIKV circulated undetected in multiple regions for many months before the first locally transmitted cases were confirmed, highlighting the importance of surveillance of viral infections. We identify mutations with possible functional implications for ZIKV biology and pathogenesis, as well as those that might be relevant to the effectiveness of diagnostic tests

    Energy and protein balance of high milk yield dairy cows on an example of family farm

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    W pracy przedstawiono analizę energetycznego i białkowego zrównoważenia żywienia krów. Badania przeprowadzono w latach 2009–2012, w gospodarstwie rodzinnym, na stadzie ok. 50 krów. W okresie badań stado uległo podwojeniu, a przeciętna roczna wydajność mleczna zwiększyła się z 8160 do 10 291 kg*szt-1. Wraz ze wzrostem wydajności liczonej za 305 dni laktacji zmniejszała się zawartość białka w mleku. Świadczy to o występowaniu deficytu energetycznego krów o wydajności większej niż 11 tys. kg mleka. Zawartość białka w mleku była związana z fazą laktacji – najmniejsza była w pierwszych 100 dniach, a największa w końcowej części laktacji. Ilość białka podawanego krowom w paszach zasadniczo odpowiadała ich potrzebom we wszystkich fazach laktacji. Deficyt białka podawanego w paszy występował u 7,3–10,6% krów w stadzie. Zdrowotność wymion krów i jakość higieniczna mleka w 2012 r. znacznie się poprawiły i stan obecny można ocenić jako dobry.The paper presents analysis of feeding cows for balance of energy and protein. The study was carried out in 2009–2012 in the family farm with herd of about 50 cows. At that time, the number of cows in herd has doubled and average annual milk yield increased from 8160 kg*cow-1 to 10 291 kg*cow-1. The high milk production per 305 days of lactation caused the decrease of protein content in milk. This indicates energy deficit in feed for cows with high milk yield (over 11 000 kg*y-1*cow-1). The protein content in milk was related to phase of lactation. The lowest was in the first 100 days and the highest at the end of lactation. The protein content in fodder was balanced according to the cows needs at all stages of lactation. The protein deficit occurred in 7.3 to 10.6% of cows in the herd. The sanitary conditions of cow udder and hygienic quality of milk in 2012, greatly improved and current status can be assessed as good
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