Biological Communications 2022-06-24T17:46:21+03:00 Anton A. Nizhnikov Open Journal Systems <p>Biological Communications is a rebranded new title of the former journal «Vestnik of Saint Petersburg University. Series 3. Biology». The journal was founded as «Vestnik of Leningrad University» in 1946.&nbsp;Since 1953, it was published under several series. In 1956 the series «Biology» was first established.&nbsp;As its predecessors, Biological Communications is published at a quarterly&nbsp;basis.</p> The digenean complex life cycle: phylostratigraphy analysis of the molecular signatures 2022-06-24T17:46:18+03:00 Maksim Nesterenko Sergei Shchenkov Sofia Denisova Viktor Starunov <p>The parasitic flatworms from Digenea group have been the object of numerous in-depth studies for several centuries. The question of the evolutionary origin and transformation of the digenean complex life cycle remains relevant and open due to the biodiversity of these parasites and the absence of fossil records. However, modern technologies and analysis methods allow to get closer to understanding the molecular basis of both the realization of the cycle and its complication. In the present study, we have applied phylostratigraphy and evolutionary transcriptomics approaches to the available digenean genomic and transcriptomic data and built ancestral genomes models. The comparison results of Platyhelminthes and Digenea ancestor genome models made it possible to identify which genes were gained and duplicated in the possible genome of digenean ancestor. Based on the bioprocesses enrichment analysis results, we assumed that the change in the regulation of many processes, including embryogenesis, served as a basis for the complication of the ancestor life cycle. The evolutionary transcriptomics results obtained revealed the “youngest” and “oldest” life cycle stages of <em>Fasciola gigantica</em>, <em>F. hepatica</em>, <em>Psilotrema simillimum</em>, <em>Schistosoma mansoni</em>, <em>Trichobilharzia regenti</em>, and <em>T. szidati</em>. Our results can serve as a basis for a more in-depth study of the molecular signatures of life cycle stages and the evolution transformation of individual organ systems and stage-specific traits.</p> 2022-06-24T00:00:00+03:00 Copyright (c) 2022 Maksim Nesterenko, Sergei Shchenkov, Sofia Denisova, Viktor Starunov Rate of spontaneous polyploidization in haploid yeast <em>Saccharomyces cerevisiae</em> 2022-06-24T17:46:12+03:00 Yulia Andreychuk Anna Zhuk Elena Tarakhovskaya Sergei Inge-Vechtomov Elena Stepchenkova <p>Polyploidization is involved in a variety of biological processes. It is one of the principal mechanisms of new species formation since it provides material for gene diversification and subsequent selection. Multiple cases of polyploidization were registered in different branches of the evolutionary tree of eukaryotes. Besides its role in evolution, polyploidization affects gene expression in living cells: pathological genome duplications often happen in cancer cells. The mechanisms and consequences of polyploidization are being studied extensively. However, quantitative determination of the polyploidization rate is challenging due to its low frequency and the absence of selective genetic markers that would phenotypically distinguish between haploids and polyploids. Our work describes a robust and straightforward method for discriminating haploid and polyploid states in the yeast <em>Saccharomyces cerevisiae</em>, a model organism for studying different aspects of polyploidization. The measurement of polyploidization rate showed that in yeast cells this process is mainly caused by autodiploidization rather than mating-type switching followed by hybridization.</p> 2022-06-24T00:00:00+03:00 Copyright (c) 2022 Yulia Andreychuk, Anna Zhuk, Elena Tarakhovskaya, Sergei Inge-Vechtomov, Elena Stepchenkova Lithobiotic cyanobacteria diversity of the Karelian Isthmus 2022-06-24T17:46:15+03:00 Oksana Rodina Denis Davydov Dmitry Vlasov <p>This work presents data obtained as a result of studying the composition of cyanobacteria in lithobiotic communities on various substrates (Ruskeala marble, rapakivi-granite, granite gneiss) in different light conditions on the territory of the Karelian Isthmus: Leningrad Oblast, Republic of Karelia, and South Finland. The species composition of cyanobacteria was revealed, and the species composition on certain types of substrates was analyzed. A total of 49 species of cyanobacteria were noted for the Republic of Karelia (13 of which were not previously recorded in this territory). The detailed taxonomic and environmental characteristics of species are given. Changes in the species diversity of cyanobacteria in connection with specific habitats are shown. The type of substrate, the degree of moisture, and illumination are noted as the main factors determining the diversity of cyanobacteria in lithobiotic communities.</p> 2022-06-24T00:00:00+03:00 Copyright (c) 2022 Oksana Rodina, Denis Davydov, Dmitry Vlasov Changes in heart rate during electrical stimulation of the atrium in rainbow trout (<em>Oncorhynchus mykiss</em>) at low temperature 2022-06-24T17:46:21+03:00 Natalya Kibler Vladimir Nuzhny Dmitry Shmakov <p>In this work, we investigated the effect of high heart rate (HR) in vivo on the electrical properties and pumping functions of the heart ventricle of the rainbow trout (<em>Oncorhynchus mykiss</em>) at low ambient temperatures. HR was altered by atrial pacing. The electrocardiogram (ECG) parameters and hemodynamic parameters of the heart ventricle of rainbow trout adapted to a temperature of 5–7 °C were studied from the normal sinus rhythm (21.6 ± 4.9 bpm) to the maximum possible HR. Results show that a HR of about 60 bpm is the upper limit of the normal functional activity of the ventricle of the heart. An increase in heart rate up to 60 bpm leads to an increase in the PQ interval and QRS complex, a decrease in the QT interval on the ECG, and a violation of the rhythmic activity of the heart (i.e., the occurrence of extrasystole), as well as to a considerable change in the hemodynamic parameters of the ventricle of the heart and a decrease in its contractile properties. After a period of ventricular extrasystole for several minutes (10–15 min), the activity of the sinus node resumes but with a lower HR compared with the initial HR. The duration of the QRS complex recovers to the initial one, and the PQ and QT intervals increase. Maximum systolic pressure and end-diastolic pressure also return to their original values after extrasystolic contraction. After the experimental extrasystole, the phenomenon of the absence of an increase in HR is observed. The arising extrasystole probably has a functional nature and is one of the mechanisms of electromechanical homeostatic control in the heart.</p> 2022-06-24T00:00:00+03:00 Copyright (c) 2022 Natalya Kibler, Vladimir Nuzhny, Dmitry Shmakov Lateralization in the visual perception of a potential source of danger in free-ranging steppe marmots (<em>Marmota bobak</em>) 2022-06-24T17:46:09+03:00 Irina Demina Alexander Dyomin Karina Karenina <p>A variety of vertebrate species display lateralization of visual perception of threat. However, the vast majority of studies were carried out in the laboratory conditions, and little is known about the relevance of this lateralization for animals in their natural environment. The aim of our work was to study lateralized visual perception of potential threat in the steppe marmot. The asymmetric use of visual fields when reacting to an approaching threat was assessed in two wild populations of marmots. The results showed that marmots predominantly used the right eye for threat monitoring. A significant impact of anthropogenic disturbance was found both within and between the populations. The right-sided preference was reduced in animals inhabiting areas with high degree of anthropogenic disturbance. The eye (left/right) a focal individual used for threat monitoring did not influence its flight initiation distance. Contrary to a previous study, our results do not suggest that the use of a particular eye affects the speed of threat assessment.</p> 2022-06-24T00:00:00+03:00 Copyright (c) 2022 Irina Demina, Alexander Dyomin, Karina Karenina Role of the MBP protein in myelin formation and degradation in the brain 2022-06-24T17:46:06+03:00 Aleksandr Shenfeld Alexey Galkin <p>The compact myelin sheath functions as an insulator for efficient conduction of nerve impulses. The formation of myelin sheaths around the axons of the most actively functioning neurons continues not only at the stage of brain development, but also in the process of learning and acquiring certain skills. Pathological or age-related disruption in myelin results in nerve conduction failure and neurodegeneration. Myelin Basic Protein (MBP) is the main constituent of the myelin sheath, representing about 30 % of the total myelin proteins in the central nervous system. Deletion in the MBP coding gene in mutant mice causes a severe neurological phenotype associated with rapid death of newborns. In this review, we discuss the current understanding of the role of the MBP protein in the formation of compact myelin and in neurodegeneration associated with demyelination.</p> 2022-06-24T00:00:00+03:00 Copyright (c) 2022 Aleksandr Shenfeld, Alexey Galkin