Findings to the flora of Russia and adjacent countries: New national and regional vascular plant records, 4

With this paper we continue a new annual series, the main purpose of which is to make significant floristic findings from Russia and neighboring countries more visible in Russia and abroad. In total, this paper presents new records for 48 vascular plant species from 6 Eurasian countries, obtained during field explorations, as well as during taxonomic revisions of herbarium materials. For the first time, a new locality of Leontopodium leiolepis is recorded for Russia, Rheum uzengukuushi for China, Rorippa prolifera for Lithuania, Lappula marginata for Kyrgyzstan and Tajikistan, Anthriscus caucalis, Chenopodium ficifolium, Euphorbia prostrata for Uzbekistan, Adonis × hybrida, Potamogeton × franconicus, Solidago × niederederi for the Asian part of Russia, Echinochloa esculenta, Poa jamalinensis, Puccinellia poecilantha for Siberia, Potentilla intermedia for the Caucasus, Rhynchospora alba for the Russian part of Altai, Poa sphondylodes, Veronica beccabunga for Eastern Siberia, Asclepias syriaca for the Republic of Altai, Chimaphila umbellata, Orobanche korshinskyi, Veronica scutellata for the Republic of Buryatia, Cirsium alatum, Thalictrum simplex for the Republic of Crimea, Thymus rariflorus, Th. terekensis for the Republic of Ingushetia, Berberis thunbergii, Crataegus maximowiczii, Prunus serotina for the Republic of Mordovia, Oenothera villosa for the Republic of Tatarstan, Astragalus sulcatus, Galium mollugo for the Republic of Tyva, Phragmites altissimus for the Chelyabinsk Region, Senecio dubitabilis for the Magadan Region, Asclepias syriaca, Galatella villosa, Potentilla recta for the Novosibirsk Region, Dodartia orientalis for the Omsk Region, Viola hultenii for the Sakhalin Region, Phragmites tzvelevii for the Samara Region and the Middle Volga, Jacobaea ferganensis for the Samara Region, Carex media, Impatiens parviflora for the Tyumen Region. There are some more findings which are not new for the region but they contribute significantly to the understanding of species distribution

Lecithin Prevents Cortical Cytoskeleton Reorganization in Rat Soleus Muscle Fibers under Short-Term Gravitational Disuse.

The aim of this study was to prevent the cortical cytoskeleton reorganization of rat soleus muscle fibers under short-term gravitational disuse. Once a day, we injected the right soleus muscle with 0.5 ml lecithin at a concentration of 200 mg/ml and the left soleus muscle with a diluted solution in an equal volume for 3 days prior to the experiment. To simulate microgravity conditions in rats, an anti-orthostatic suspension was used according to the Ilyin-Novikov method modified by Morey-Holton et al. for 6 hours. The following groups of soleus muscle tissues were examined: "C", "C+L", "HS", and "HS+L". The transversal stiffness of rat soleus muscle fibers after 6 hours of suspension did not differ from that of the control group for the corresponding legs; there were no differences between the groups without lecithin «C» and «HS» or between the groups with lecithin "C+L" and "HS+L". However, lecithin treatment for three days resulted in an increase in cell stiffness; in the "C+L" group, cell stiffness was significantly higher by 22.7% (p < 0.05) compared with that of group "C". The mRNA content of genes encoding beta- and gamma-actin and beta-tubulin did not significantly differ before and after suspension in the corresponding groups. However, there was a significant increase in the mRNA content of these genes after lecithin treatment: the beta-actin and gamma-actin mRNA content in group "C+L" increased by 200% compared with that of group "C", and beta-tubulin increased by 100% (as well as the mRNA content of tubulin-binding proteins Ckap5, Tcp1, Cct5 and Cct7). In addition, desmin mRNA content remained unchanged in all of the experimental groups. As a result of the lecithin injections, there was a redistribution of the mRNA content of genes encoding actin monomer- and filament-binding proteins in the direction of increasing actin polymerization and filament stability; the mRNA content of Arpc3 and Lcp1 increased by 3- and 5-fold, respectively, but the levels of Tmod1 and Svil decreased by 2- and 5-fold, respectively. However, gravitational disuse did not result in changes in the mRNA content of Arpc3, Tmod1, Svil or Lcp1. Anti-orthostatic suspension for 6 hours resulted in a decrease in the mRNA content of alpha-actinin-4 (Actn4) and alpha-actinin-1 (Actn1) in group "HS" compared with that of group "C" by 25% and 30%, respectively, as well as a decrease and increase in the ACTN4 protein content in the membrane and cytoplasmic fractions, respectively. Lecithin injection resulted in an increase in the Actn1 and Actn4 mRNA content in group "C+L" by 1.5-fold and more than 2-fold, respectively, compared with the levels in group "C". Moreover, in group "HS+L", the mRNA content did not change in these genes compared with the levels in group "C+L", and the ACTN4 protein content in the membrane and cytoplasmic fractions also remained unchanged. Thus, lecithin prevented the reduction of Actn1 and Actn4 mRNA and the migration of ACTN4 from the cortical cytoskeleton to the cytoplasm

Relative cytochrome <i>c</i> (CYCS, MW = 15 kDa) content in the membrane-mitochondrial protein fraction (MF) and cytoplasmic protein fraction (CF) of soleus muscle fibers of rats after short-term gravitational unloading.

<p>On typical Western blot images: 1 –group «C», 2 –group «HS», 3 –group «C+L», 4 –group «HS+L».</p

Expression level of genes encoding cytoskeletal proteins in the soleus muscle fibers of rats after short-term gravitational unloading.

<p>(A) Main cytoskeletal proteins: microfilaments (<i>Actb</i>, <i>Actg</i>), microtubules (<i>Tubb2b</i>), intermediate filaments (<i>Des</i>). (B) Microtubules- and tubulin-binding proteins. (C) Actin monomers-binding proteins. (D) Actin filaments-binding proteins. Hereafter: a horizontal line determines equal means; *–p < 0.05 means of group «C+L» compared to group «C» in this figure, **–p < 0.05 means of group «HS» compared to group «C».</p

Expression levels of genes encoding metabolic proteins in the soleus muscle fibers of rats after short-term gravitational unloading: cytochrome <i>c</i> (<i>Cycs</i>) and glyceraldehyde 3-phosphate dehydrogenase (<i>Gapdh</i>).

<p>Expression levels of genes encoding metabolic proteins in the soleus muscle fibers of rats after short-term gravitational unloading: cytochrome <i>c</i> (<i>Cycs</i>) and glyceraldehyde 3-phosphate dehydrogenase (<i>Gapdh</i>).</p

Typical force curves obtained using transversal stiffness measurements of rat soleus muscle fibers under 6 hours short-term (6 hours) anti-orthostatic suspension with and without lecithin treatment (see Material and methods section).

<p>Typical force curves obtained using transversal stiffness measurements of rat soleus muscle fibers under 6 hours short-term (6 hours) anti-orthostatic suspension with and without lecithin treatment (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0153650#sec002" target="_blank">Material and methods</a> section).</p

Experimental design.

<p>Experimental design.</p

Relative protein content in the membrane protein fraction (MF) and cytoplasmic protein fraction (CF) of soleus muscle fibers of rats after short-term gravitational unloading.

<p>(A) Alpha-actinin-1 (ACTN1, MW = 100 kDa) content. (B) Alpha-actinin-4 (ACTN4, MW = 105 kDa) content. On the typical Western blot images: 1 –group «C», 2 –group «HS», 3 –group «C+L», 4 –group «HS+L».</p

Possible role of non-muscle alpha-actinins in muscle cell mechanosensitivity.

The main hypothesis suggested that changes in the external mechanical load would lead to different deformations of the submembranous cytoskeleton and, as a result, dissociation of different proteins from its structure (induced by increased/decreased mechanical stress). The study subjects were fibers of the soleus muscle and cardiomyocytes of Wistar rats. Changes in external mechanical conditions were reconstructed by means of antiorthostatic suspension of the animals by their tails for 6, 12, 18, 24 and 72 hours. Transversal stiffness was measured by atomic force microscopy imaging; beta-, gamma-actin, alpha-actinin 1 and alpha-actinin 4 levels in membranous and cytoplasmic fractions were quantified by Western blot analysis; expression rates of the corresponding genes were studied using RT-PCR.In 6 hours, alpha-actinin 1 and alpha-actinin 4 levels decreased in the membranous fraction of proteins of cardiomyocytes and soleus muscle fibers, respectively, but increased in the cytoplasmic fraction of the abovementioned cells. After 6-12 hours of suspension, the expression rates of beta-, gamma-actin, alpha-actinin 1 and alpha-actinin 4 were elevated in the soleus muscle fibers, but the alpha-actinin 1 expression rate returned to the reference level in 72 hours. After 18-24 hours, the expression rates of beta-actin and alpha-actinin 4 increased in cardiomyocytes, while the alpha-actinin 1 expression rate decreased in soleus muscle fibers. After 12 hours, the beta- and gamma-actin content dropped in the membranous fraction and increased in the cytoplasmic protein fractions from both cardiomyocytes and soleus muscle fibers. The stiffness of both cell types decreased after the same period of time. Further, during the unloading period the concentration of nonmuscle actin and different isoforms of alpha-actinins increased in the membranous fraction from cardiomyocytes. At the same time, the concentration of the abovementioned proteins decreased in the soleus muscle fibers

Drosophila melanogaster Oocytes after Space Flight: The Early Period of Adaptation to the Force of Gravity

The effect of space flight factors and the subsequent adaptation to the Earth&rsquo;s gravity on oocytes is still poorly understood. Studies of mammalian oocytes in space present significant technical difficulties; therefore, the fruit fly Drosophila melanogaster is a convenient test subject. In this study, we analyzed the structure of the oocytes of the fruit fly Drosophila melanogaster, the maturation of which took place under space flight conditions (the &ldquo;Cytomehanarium&rdquo; experiment on the Russian Segment of the ISS during the ISS-67 expedition). The collection of the oocytes began immediately after landing and continued for 12 h. The flies were then transferred onto fresh agar plates and oocyte collection continued for the subsequent 12 h. The stiffness of oocytes was determined by atomic force microscopy and the content of the cytoskeletal proteins by Western blotting. The results demonstrated a significant decrease in the stiffness of oocytes in the flight group compared to the control (26.5 &plusmn; 1.1 pN/nm vs. 31.0 &plusmn; 1.8 pN/nm) against the background of a decrease in the content of some cytoskeletal proteins involved in the formation of microtubules and microfilaments. This pattern of oocyte structure leads to the disruption of cytokinesis during the cleavage of early embryos