The role of microRNA in abiotic stress response in plants

Regulation of gene expression via microRNA is the key mechanism of response to biotic and abiotic stresses in plants. There are a lot of experimental data on the biological function of microRNAs in response to different stresses in various plant species. This review contains up-to-date information on molecular mechanisms of microRNA action in plants in response to abiotic stresses, including drought, salinity, mineral nutrient deficiency or imbalance.     

Mutational Profiling of Pediatric Myeloid Leukemia Subtypes without Clinically Significant Chromosomal Aberrations

Molecular Biology - The discovery of novel significant molecular and genetic markers is important for the diagnostics, prognosis, and therapy selection in hematological malignancies. Distinct...     

Phylogenetic and compositional diversity are governed by different rules: a study of fleas parasitic on small mammals in four biogeographic realms

We studied patterns of phylogenetic and compositional diversity of fleas parasitic on small mammals and asked whether these patterns are affected by environmental variation or evolutionary/historical processes. We considered environmental variation via both off‐host (air temperature, precipitation, the amount of green vegetation, latitude) and host‐associated (phylogenetic and species composition) environments. The indicators of evolutionary/historical processes were phylogenetic and compositional uniqueness estimated via phylogenetic or compositional, respectively, β‐diversity of either fleas or hosts. We found that phylogenetic uniqueness of flea assemblages was the main predictor of their phylogenetic diversity in all realms. In addition, host phylogenetic diversity and uniqueness played also some role in the Palearctic, whereas the effect of the off‐host environment was either extremely weak or absent. Compositional diversity of fleas was consistently affected by compositional diversity of hosts in all realms except the Neotropics. The effect of the off‐host environment on compositional flea diversity was substantial in all realms except the Palearctic. No effect of latitude on either metric of flea diversity was found. We conclude that phylogenetic diversity of fleas is driven mainly by evolutionary/historical processes, whereas drivers of their compositional diversity are associated with current ecological conditions.     

Targeted genomic integration of EGFP under tubulin beta 3 class III promoter and mEos2 under tryptophan hydroxylase 2 promoter does not produce sufficient levels of reporter gene expression

Neuronal tracing is a modern technology that is based on the expression of fluorescent proteins under the control of cell type–specific promoters. However, random genomic integration of the reporter construct often leads to incorrect spatial and temporal expression of the marker protein. Targeted integration (or knock-in) of the reporter coding sequence is supposed to provide better expression control by exploiting endogenous regulatory elements. Here we describe the generation of two fluorescent reporter systems: enhanced green fluorescent protein (EGFP) under pan-neural marker class III β-tubulin (Tubb3) promoter and mEos2 under serotonergic neuron-specific tryptophan hydroxylase 2 (Tph2) promoter. Differentiation of Tubb3-EGFP embryonic stem (ES) cells into neurons revealed that though Tubb3-positive cells express EGFP, its expression level is not sufficient for the neuronal tracing by routine fluorescent microscopy. Similarly, the expression levels of mEos2-TPH2 in differentiated ES cells was very low and could be detected only on messenger RNA level using polymerase chain reaction-based methods. Our data shows that the use of endogenous regulatory elements to control transgene expression is not always beneficial compared with the random genomic integration.     

KatG Ser3 15Thr mutation as the main reason of isoniazid resistance in Mycobacterium tuberculosis isolated in the Novosibirsk and Kemerovo Regions

KatG Ser3 15Thr mutation is one of the main reasons of resistance to isoniazid in Mycobacterium tuberculosis isolates. The frequency rate of the above mutation among isoniazid-resistant isolates made 94% in Novosibirsk Region and 93% in Kemerovo Region. The use of PCR-restriction fragment length polymorphism (PCR-RFLP) can be regarded as an adequate method for rapid screening of isoniazid resistance in Mycobacterium tuberculosis isolated in the West-Siberian Region.     

Prevalence of alleles associated with HIV resistance in Russia

Genetic polymorphisms of CCR5, CCR2, and SDF1 genes have been associated with resistance during human immunodeficiency virus type 1 (HIV-1) infection and disease progression. In the present report, we studied the frequency and co-occurrence of CCR5Delta32, CCR5-59029A/G, CCR2-64I, and SDF1-3'A allelic variants among HIV-1-seronegative individuals (n = 171) in Moscow. Observed allelic frequencies were 0.0906 [95% confidence interval (CI), 0.06-0.1212] for CCR5Delta32, 0.4072 (95% CI, 0.3542-0.4602) for CCR5-59029G, 0.1061 (95% CI, 0.0728-0.1394) for CCR2-64I, and 0.2218 (95% CI 0.1715-0.2721) for SDF1-3'A. A significant linkage disequilibrium (p = 0.0034) between CCR2-64I and SDF1-3'A alleles was observed.     

Brain vessels in the rats exposed to primary and repeated tail-suspension. Minimization of structural changes after repeated exposure

The aim of study was histological examination of brain vessels in the rats exposed to repeated tail-suspension (TS). The rats were subjected to 30-day TS, then readapted to horizontal position for 30 days and again exposed to 14-day TS simultaneously with the rats which were underwent to 14-day TS for the first time. 30-day TS induced in brain vessels the adaptive changes hindering the excessive blood inflow to brain--spasm and hypertrophy of muscle-elastic valves in extra- and intracerebral arteries and also the destructive changes--loss of vascular tone in extra- and intracerebral arteries, plethora in extra- and intracerebral veins, intracerebral venules and capillaries, conglutination of erythrocytes in capillaries, plasmatization of veins and capillaries and edema of brain tissue pointing out in total the increase in blood inflow to the brain and difficulty of blood outflow. After 30-day readaptation of TS-rats to horizontal position only adaptive changes in extracerebral arteries and intracerebral capillaries (cell proliferation) and edema of brain tissue were revealed. After repeated, 14-day TS in spite of new redistribution of blood to the head, in contrast to the vessel alterations after primary 14-day TS, the adaptive and destructive changes in brain vessels were lack, excluding only moderate plethora of intracerebral veins, cell proliferation in capillaries and weak signs of edema.