L1 (LINE-1) retrotransposable elements provide a "fossil" record of the phylogenetic history of murid rodents

The single most difficult problem in phylogenetic analysis is deciding whether a shared taxonomic character is due to common ancestry or one that appeared independently due to convergence, parallelism, or reversion to an ancestral state. Mammalian L1 retrotransposons undergo periodic amplifications in which multiple copies of the elements are interspersed in the genome. Because these elements apparently are transmitted only by inheritance and are retained in the genome, a shared L1 amplification event can only be an inherited ancestral character. We propose that L1 amplification events can be an excellent tool for analyzing mammalian evolution and demonstrate here how we addressed several refractory problems in rodent systematics using L1 DNA as a taxonomic character.      

Annual cycle of nanophytoplankton in coastal waters of the Barents Sea

The seasonal dynamics of biomass and size structure of nanophytoplankton in Central Murman (off the southern coast of the Barents Sea) are described according to the results of six-year continuous observations. The pattern of the annual successional cycle indicates that the nanophytoplankton community as a structural unit of coastal pelagic algocenoses is a specific integrated ecological group of primary producers. The issue of a major contribution of nanoalgae to the total biomass and production of the autotrophic component of coastal ecosystems in Arctic seas is discussed.     

Annual cycle of the planktonic phytocenosis in the Ob-Enisei shallow zone of the Kara Sea

This paper analyzes data on the state of the pelagic microalgae community of the Kara Sea for all hydrological seasons. The data were obtained during complex in situ observations in 1996–2006. Four phases in the annual succession cycle of the phytoplankton of the nearshore continental area of the Kara Sea were identified: a prevernal phase (cryoflora bloom), vernal phase (ice-edge bloom), summer-fall phase (mixed synthesis phase), and winter phase (dormant phase). These periods are clearly distinguished from each other in their composition of dominating species complexes and quantitative characteristics, i.e., the numbers and biomasses of microalgae. In the investigated region, which is completely covered by ice during most of the year, the primary production processes begin at the same time as in ice-free coastal areas. Growth and blooming of cryoflora occur under the ice cover long before it breaks down. The peak development of the pelagic microalgae community, which is comparable to the spring peak of microalgae in ice-free coastal areas, is observed in the summer, when freshwater runoff from large rivers increases sharply.     

Modification of Oligopeptides Increasing the Effectiveness of Their Interaction with Interleukin-8 in Human Blood Plasma

Russian Journal of Bioorganic Chemistry - Molecular modeling, which identified several peptide sequences, was carried out in search for compounds capable of reducing the interleukin-8 concentration...     

Plant virus infection development as affected by heavy metal stress

The work was focused on the investigation of possible dependencies between the development of viral infection in plants and the presence of high heavy metal concentrations in soil. Field experiments have been conducted in order to study the development of systemic tobacco mosaic virus (TMV) infection in Lycopersicon esculentum L. cv. Miliana plants under effect of separate salts of heavy metals Cu, Zn and Pb deposited in soil. As it is shown, simultaneous effect of viral infection and heavy metals in tenfold maximum permissible concentration leads to decrease of total chlorophyll content in experiment plants mainly due to the degradation of chlorophyll a. The reduction of chlorophyll concentration under the combined influence of both stress factors was more serious comparing to the separate effect of every single factor. Plants' treatment with toxic concentrations of lead and zinc leaded to slight delay in the development of systemic TMV infection together with more than twofold increase of virus content in plants that may be an evidence of synergism between these heavy metal's and virus' effects. Contrary, copper although decreased total chlorophyll content but showed protective properties and significantly reduced amount of virus in plants.     

Macrokinetic equations of pH effect on the growth of Actinomyces aureofaciens and biosynthesis of tetracycline]

The effect of pH on the culture respiration rate at different concentrations of glucose in the medium was studied. It was found that the hydrogen ions showed their effect irrespective of the subsrate concentration in the medium. In this connection a type of macrokinetic equations of the effect of pH on the growth and antibiotic biosynthesis was chosen. The constants of the model were determined.     

DNA methylation-associated colonic mucosal immune and defense responses in treatment-na?ve pediatric ulcerative colitis

Inflammatory bowel diseases (IBD) are emerging globally, indicating that environmental factors may be important in their pathogenesis. Colonic mucosal epigenetic changes, such as DNA methylation, can occur in response to the environment and have been implicated in IBD pathology. However, mucosal DNA methylation has not been examined in treatment-naïve patients. We studied DNA methylation in untreated, left sided colonic biopsy specimens using the Infinium HumanMethylation450 BeadChip array. We analyzed 22 control (C) patients, 15 untreated Crohn’s disease (CD) patients, and 9 untreated ulcerative colitis (UC) patients from two cohorts. Samples obtained at the time of clinical remission from two of the treatment-naïve UC patients were also included into the analysis. UC-specific gene expression was interrogated in a subset of adjacent samples (5 C and 5 UC) using the Affymetrix GeneChip PrimeView Human Gene Expression Arrays. Only treatment-naïve UC separated from control. One-hundred-and-twenty genes with significant expression change in UC (> 2-fold, P < 0.05) were associated with differentially methylated regions (DMRs). Epigenetically associated gene expression changes (including gene expression changes in the IFITM1, ITGB2, S100A9, SLPI, SAA1, and STAT3 genes) were linked to colonic mucosal immune and defense responses. These findings underscore the relationship between epigenetic changes and inflammation in pediatric treatment-naïve UC and may have potential etiologic, diagnostic, and therapeutic relevance for IBD.