Vol 33, No 4 (2018)

Today, the effectiveness of scientific research is increasingly often determined by the size of grants obtained, the number of publications, and the level of their prestige, as well as the ability to attract public attention, rather than by well-defined problems and stringent methods of their solutions. This trend is disastrous for science. Bibliometric data, useful as a subsidiary method of evaluation, cannot replace expert opinions based on the analysis of the content of the paper. The pressure making scientists publish is leading to poor quality publications. The irreproducibility of research papers, amounting in oncology up to 75%, is now commonplace. This results in an incremental character of science, when the research is reduced to a systematic refinement of the available data. As a consequence, researchers and financing focus on known and common research directions, while there are still many understudied areas avoided by researchers due to the risk of failure and loss of publications. For instance, 1000 of 4000 E. coli genes remain absolutely uninvestigated. Clearly, there are even more unknown areas in complex multicellular organisms, including humans. This has created prerequisites to reduce the probability of large scientific discoveries, which are often made by chance. Science needs better financing and this is aggravated by the fact that the allocated funds are distributed without considering the scientific value of research and the accidental character of discoveries. The author draws attention to the importance of financial support of scientific schools that are the most probable centers for obtaining new scientific knowledge and preparing the ground for scientific discoveries.

In this review, the role of transposons in the origin of viruses, losing the traits of their evolutionary precursors due to their high mutability, is considered. However, there are a number of common properties of viruses and transposons suggesting their phylogenetic relationship, including the ability to integrate into the host genome, specific activation in certain tissues, high degree of mutability, the existence of virophages propagating only in the presence of another virus (which is similar to non-autonomous transposons, for which the expression products of autonomous ones are required). Ideas about the emergence of viruses from transposons in evolution are discussed. The genomic elements exhibiting a dual nature of existence as mobile genetic elements and viruses are found: polintons, Tlr elements, and PLV viruses. It is assumed that a horizontal transfer (HT) of transposons, during the natural selection of which the elements possessing the virulence properties are preserved (while the genes required for the integration can mutate), is a key event required for turning into viruses. The horizontal transposon transfer, which is common in all representatives of living organisms, is accompanied by their variability required for the acquisition of new adaptive traits. In the course of evolution, the mechanisms of protection against viruses and transposons, including RNA interference, DNA methylation, and histone modification, began to be used to control the operation of the genomes, providing intercellular interactions; this explains the emergence of multicellular organisms. In the evolution of eukaryotes, the transposons have been used successfully for transformations of regulatory gene networks, as well as possible sources of new genes encoding both proteins and non-coding RNA, the fragmentary translation of which can produce short functional peptides. Thus, the products of transposon transcription and translation are the most important sources of evolutionary transformations; these mechanisms could be the basis for the evolution of viruses and the emergence of the fundamental properties of living organisms when they appear.

Nanoparticles of cadmium sulfide (NpCdS) and zinc sulfide (NpZnS) are shown to be formed in the presence of Shewanella oneidensis MR-1 bacteria. These nanoparticles were located in the culture liquid and had a spherical shape. The nanoparticles were characterized by a small range of size distribution; the maximal size of NpCdS and NpZnS was approximately 5–6 nm; over 70% of the nanoparticles had a size of approximately 2–4 nm. The effective diameter of NpCdS and NpZnS was 158.9 nm and 219.3 nm, respectively. The value of the ζ-potential of NpCdS and NpZnS was –22.43 and –31.46 mV, respectively, which characterized the aqueous suspensions of these nanoparticles as metastable. The selectivity of the adsorption of certain proteins from the common pool of the protein molecules, synthesized by S. oneidensis MR-1 strain during cultivation, on the surface of nanoparticles is ascertained. Independently of the chemical nature of the particles (NpCdS and NpZnS), the protein molecules adsorbed on their surface are shown to have similar molecular weights. For the first time, biogenic NpCdS and NpZnS are used to develop a model composite system by the immobilization of amine-containing poly(glycidyl methacrylate) (PGMA) microspheres on the surface.

Marker chromosomes are structurally abnormal chromosomes that may be supernumerary in karyotype or replace one of the chromosomes. Marker chromosomes very frequently can be a cause of different pathologies, including a intellectual disability. This study considers the molecular cytogenetic analysis of an acrocentric marker chromosome in a patient with autism and a intellectual disability. With the help of the painting probe localization of human chromosomes, its origin from the pericentromeric regions of the p and q arms of chromosome 15 is shown. For more detailed detection of the region of origin of this chromosome, its microdissection following localization on both healthy control and patient metaphase plates was carried out. Its origin from the nucleolus-containing chromosome 15 is confirmed. Because of the rDNA-containing plasmid localization, two of the ribosome RNA gene clusters were detected on the patient’s chromosomes. Ag-NOR staining showed that both clusters are active. A possible contribution of the revealed chromosome pathology in clinical picture formation is discussed.

This paper presents the results of selecting the most promising single nucleotide polymorphisms associated with cardiovascular diseases in genome-wide association studies. Twenty such loci were identified. For eight of those loci, protocols for discrimination of the corresponding allelic variants with a real-time polymerase chain reaction (TaqMan) were developed and used for genotyping a sample of Russian individuals from Moscow.

There is a lack of information concerning commensal Neisseria, as most studies focus on pathogenic Neisseria. To evaluate the use of Multilocus Sequence Typing (MLST) as a molecular identification tool, we determined the sequences of 700 bp fragments in seven housekeeping genes (abcZ, adk, aroE, fumC, gdh, pdhC and pgm) of 24 commensal Neisseria isolates collected from neutropenic patients in the Bone Marrow Transplant Center of Tunisia. Results were then compared to those obtained by conventional biochemical testing. In 79% (19/24), more than one possibility was given by MLST and in 46% (11/24), one of the possibilities offered by MLST, agreed with the result given by conventional biochemical testing.