HIV-1 RNA genome dimerizes on the plasma membrane in the presence of Gag protein

Retroviruses package a dimeric genome comprising two copies of the viral RNA. Each RNA contains all of the genetic information for viral replication. Packaging a dimeric genome allows the recovery of genetic information from damaged RNA genomes during DNA synthesis and promotes frequent recombination to increase diversity in the viral population. Therefore, the strategy of packaging dimeric RNA affects viral replication and viral evolution. Although its biological importance is appreciated, very little is known about the genome dimerization process. HIV-1 RNA genomes dimerize before packaging into virions, and RNA interacts with the viral structural protein Gag in the cytoplasm. Thus, it is often hypothesized that RNAs dimerize in the cytoplasm and the RNA-Gag complex is transported to the plasma membrane for virus assembly. In this report, we tagged HIV-1 RNAs with fluorescent proteins, via interactions of RNA-binding proteins and motifs in the RNA genomes, and studied their behavior at the plasma membrane by using total internal reflection fluorescence microscopy. We showed that HIV-1 RNAs dimerize not in the cytoplasm but on the plasma membrane. Dynamic interactions occur among HIV-1 RNAs, and stabilization of the RNA dimer requires Gag protein. Dimerization often occurs at an early stage of the virus assembly process. Furthermore, the dimerization process is probably mediated by the interactions of two RNA-Gag complexes, rather than two RNAs. These findings advance the current understanding of HIV-1 assembly and reveal important insights into viral replication mechanisms

A study on L-threonine and L-serine uptake in Escherichia coli K-12

In the current study, we report the identification and characterization of the yifK gene product as a novel amino acid carrier in E. coli K-12 cells. Both phenotypic and biochemical analyses showed that YifK acts as a permease specific to L-threonine and, to a lesser extent, L-serine. An assay of the effect of uncouplers and composition of the reaction medium on the transport activity indicates that YifK utilizes a proton motive force to energize substrate uptake. To identify the remaining threonine carriers, we screened a genomic library prepared from the yifK-mutant strain and found that brnQ acts as a multicopy suppressor of the threonine transport defect caused by yifK disruption. Our results indicate that BrnQ is directly involved in threonine uptake as a low-affinity but high-flux transporter, which forms the main entry point when the threonine concentration in the external environment reaches a toxic level. By abolishing YifK and BrnQ activity, we unmasked and quantified the threonine transport activity of the LIV-I branched chain amino acid transport system and demonstrated that LIV-I contributes significantly to total threonine uptake. However, this contribution is likely smaller than that of YifK. We also observed the serine transport activity of LIV-I, which was much lower compared with that of the dedicated SdaC carrier, indicating that LIV-I plays a minor role in the serine uptake. Overall, these findings allow us to propose a comprehensive model of the threonine/serine uptakesubsystem in E. coli cells

Clinical Aspects of Prevention and Management of Primary Inferior Oblique Muscle Overaction

Background. Primary inferior oblique muscle overaction (PIOOA) may occur for various reasons and happens to 72 % patients with infantile esotropia. The criterion for the first surgical step is prevalence of vertical or horizontal deviation. The choice of tactics weakening inferior oblique muscle is ambiguous.Aims: to carry out retrospective analysis of PIOOA frequency in patients with infantile esotropia; to assess influence of esodeviation reduction by a surgical, chemodenervational or prismatic method on the existing PIOOA dynamics; to assess clinical and functional results of PIOOA treatment.Methods and methods. The retrospective analysis of 572 patients’ cases lay in assessment of PIOOA frequency and rate in patients with infantile esotropia that manifested under 9 months, with different treatment tactics. The prospective part of the research included two groups of patients. Group 1 (106 patients, 222 eyes) – studying the influence of surgical treatment of PIOOA. Group 2 (127 patients, 207 eyes) – studying the effectiveness of surgical PIOOA treatment. Conclusion. PIOOA frequency in case of different treatment tactics for patients with infantile esotropia is from 17 to 69 %, and the degree of its clinical manifestation is from 1.2 ± 0.4 to 2.6 ± 0.8. Bilateral weakening of medial rectus muscle reduces its probability up to 17–19 %, and the degree of its manifestation up to 1.2 ± 0.4. In cases of combination of PIOOA with infantile esotropia from 20 to 25° with paretic component, it is reasonable to carry out esodeviation reduction by means of bilateral recession, chemorecession or prismatic correction as the first treatment stage, whereas the rate of existing PIOOA is credibly reduced. In cases of choice of tactics, which is necessary for clinically significant reduction or elimination of PIOOA, it is reasonable to carry out chemorecession, marginal partial myotomy or myectomy depending on the PIOOA manifestation

Leukemia Inhibitory Factor in Rat Fetal Lung Development: Expression and Functional Studies

Background: Leukemia inhibitory factor (LIF) and interleukin-6 (IL-6) are members of the family of the glycoprotein 130 (gp130)-type cytokines. These cytokines share gp130 as a common signal transducer, which explains why they show some functional redundancy. Recently, it was demonstrated that IL-6 promotes fetal lung branching. Additionally, LIF has been implicated in developmental processes of some branching organs. Thus, in this study LIF expression pattern and its effects on fetal rat lung morphogenesis were assessed. Methodology/Principal Findings: LIF and its subunit receptor LIFRa expression levels were evaluated by immunohistochemistry and western blot in fetal rat lungs of different gestational ages, ranging from 13.5 to 21.5 days post-conception. Throughout all gestational ages studied, LIF was constitutively expressed in pulmonary epithelium, whereas LIFRa was first mainly expressed in the mesenchyme, but after pseudoglandular stage it was also observed in epithelial cells. These results point to a LIF epithelium-mesenchyme cross-talk, which is known to be important for lung branching process. Regarding functional studies, fetal lung explants were cultured with increasing doses of LIF or LIF neutralizing antibodies during 4 days. MAPK, AKT, and STAT3 phosphorylation in the treated lung explants was analyzed. LIF supplementation significantly inhibited lung growth in spite of an increase in p44/42 phosphorylation. On the other hand, LIF inhibition significantly stimulated lung growth via p38 and Akt pathways

Defining murine organogenesis at single-cell resolution reveals a role for the leukotriene pathway in regulating blood progenitor formation.

During gastrulation, cell types from all three germ layers are specified and the basic body plan is established 1 . However, molecular analysis of this key developmental stage has been hampered by limited cell numbers and a paucity of markers. Single-cell RNA sequencing circumvents these problems, but has so far been limited to specific organ systems 2 . Here, we report single-cell transcriptomic characterization of >20,000 cells immediately following gastrulation at E8.25 of mouse development. We identify 20 major cell types, which frequently contain substructure, including three distinct signatures in early foregut cells. Pseudo-space ordering of somitic progenitor cells identifies dynamic waves of transcription and candidate regulators, which are validated by molecular characterization of spatially resolved regions of the embryo. Within the endothelial population, cells that transition from haemogenic endothelial to erythro-myeloid progenitors specifically express Alox5 and its co-factor Alox5ap, which control leukotriene production. Functional assays using mouse embryonic stem cells demonstrate that leukotrienes promote haematopoietic progenitor cell generation. Thus, this comprehensive single-cell map can be exploited to reveal previously unrecognized pathways that contribute to tissue development

LEXICAL GRAMMATICAL SPECIFICITY OF GERMAN CATHOLIC PRAYERS ON THE FEASTS OF THE DOCTORS OF THE CHURCH

Through the example of the German language, the paper analyzes a special type of Catholic liturgical text – the Priestly Prayer during the Liturgy of Hours (oration) on the Feasts of the Doctors of the Church. The study views the prayer as a type of text and describes its socio cultural specificity. The present article analyzes the prayer on the Feasts of the Doctors of the Church for lexical grammatical models (addressings, predications, pleadings and conclusions) and the most typical compositional, grammatical, and lexical features and stylistic devices (intertextual borrowings, metaphors, metonymies, antithesis, and syntactic parallelism); and traces how they create the originality of this type of prayers

The language of religion as a subject of discursive linguistics

В статье представлены различные подходы к интерпретации понятий «язык религии», «религиозный дискурс», «лингвистический анализ религиозного дискурса», рассматриваются смежные с ними объекты лингвистического анализа. The paper studies different approaches to the interpretation of concepts “language of religion”, “religious discourse”, “linguistics of religious discourse” and the various objects of linguistic analysis in the religious discourse

CROSS-LINGUISTIC TRANSFER CLASSROOM L3 ACQUISITION IN UNIVERSITY SETTING

Introduction: the paper investigates cross-linguistic influences between the two previously learnt languages and their effects on classroom L3 acquisition. The study checks the predictions of the existing theories of mechanisms of transfer into the L3 attested for naturalistic learners. The main predictions get confirmed with the population of classroom learners of English as the L3. All the participants are native speakers of Russian. They all learnt their dominant foreign language, either French or German, in the classroom. The results suggest a governing role of the Universal Grammar in classroom language learning. Materials and Methods: the experiment uses three production tasks: written production, oral production and pronunciation task. The written assignment asks the participants to translate sentences from Russian into English. The target sentence contains the existential there are that does not exist in Russian. The way the participants structure the target sentence in English allows for conclusion about possible influences of the first foreign language on the development of their L3- English. In the oral production task, the participants are prompted to produce negative sentences. The influences from previously learnt languages is traced through the placement of the negation not. In the pronunciation task Praat was used to measure the duration and the formant frequency of the nasal [N] in English. Differences in sound quality trace back to the influences from the previously learnt languages. The data were analyzed with one-way ANOVA for between and within group differences. Results: in the written task, the participants who studied German as their first foreign language prefer verb final placement in the subordinate, which is ungrammatical in English but grammatical in German. The L2-French group put the verb in the right place, but they do not use the existential there are, which required in English. In the oral task, the placement of negation is Russian-like in both groups. In pronunciation, the quality of English [N] is influenced by the amount of nasality the participants learnt before, i.e. French influences make the English [N] more nasalized than the [N] in the group with German as the first foreign language. Discussion and Conclusion: classroom learners of English as the L3 experience influences from all the previously learnt languages, the native language and the first foreign language. These findings pattern with the assumptions of the main generative theories of naturalistic L3 acquisition. Concluding that classroom language learning is governed by universal grammar, the teaching can benefit from predicting what cross-linguistic influences can be facilitative or not for the acquisition of the target language

Distant screening of schoolchildren vision as a method of prophylactic medical examination

Purpose. To study an efficacy of distant vision screening of schoolchildren, planning the ways of its effective introduction in practice, to develop promising trends of improvement.Material and methods. We developed an interactive computer program for remote examination of visual acuity, determination of far or near vision shift in refraction (into myopia or hyperopia), diagnosis of astigmatism and pathology of macular area. The results of the examination were automatically recorded in a computer database. The program was located on website of our clinic. The screening was performed among 69 secondary comprehensive schools of Novosibirsk. Depending on the quantity of the invoked tests, the examination duration lasted from 4 to 8 minutes for a group of 5 schoolchildren.Results and discussion. During four years of this project, 21293 children studying in 69 schools were distantly tested. To compare, during 8 years of our in-school examination using similar ophthalmological tests, 26829 pupils were examined. Thus, the effectiveness of distant examinations was more than 5 times higher. Visual disturbances were diagnosed in 10220 pupils (48%).Conclusions. A method of distant screening vision examinations is safe and high efficient. Database of the examination results is helpful to diagnose pathology at early stages, to follow its dynamics and to inform parents in time about the necessity of a complete ophthalmological examination and treatment of their children