Differences in brain transcriptomes of closely related baikal coregonid species

The aim of this work was to get deeper insight into genetic factors involved in the adaptive divergence of closely related species, specifically two representatives of Baikal coregonids—Baikal whitefish (Coregonus baicalensis Dybowski) and Baikal omul (Coregonus migratorius Georgi)—that diverged from a common ancestor as recently as 10–20 thousand years ago. Using the Serial Analysis of Gene Expression method, we obtained libraries of short representative cDNA sequences (tags) from the brains of Baikal whitefish and omul. A comparative analysis of the libraries revealed quantitative differences among ~4% tags of the fishes under study. Based on the similarity of these tags with cDNA of known organisms, we identified candidate genes taking part in adaptive divergence. The most important candidate genes related to the adaptation of Baikal whitefish and Baikal omul, identified in this work, belong to the genes of cell metabolism, nervous and immune systems, protein synthesis, and regulatory genes as well as to DTSsa4 Tc1-like transposons which are widespread among fishes

Signs of Selection in Synonymous Sites of the Mitochondrial Cytochrome b Gene of Baikal Oilfish (Comephoridae) by mRNA Secondary Structure Alterations

Studies over the past decade have shown a significant role of synonymous mutations in posttranscriptional regulation of gene expression, which is particularly associated with messenger RNA (mRNA) secondary structure alterations. Most studies focused on prokaryote genomes and the nuclear genomes of eukaryotes while little is known about the regulation of mitochondrial DNA (mtDNA) gene expression. This paper reveals signs of selection in synonymous sites of the mitochondrial cytochrome b gene (Cytb) of Baikal oilfish or golomyankas (Comephoridae) directed towards altering the secondary structure of the mRNA and probably altering the character of mtDNA gene expression. Our findings are based on comparisons of intraspecific genetic variation patterns of small golomyanka (Comephorus dybowski) and two genetic groups of big golomyanka (Comephorus dybowskii). Two approaches were used: (i) analysis of the distribution of synonymous mutations between weak-AT (W) and strong-GC (S) nucleotides within species and groups in accordance with mutation directions from central to peripheral haplotypes and (ii) approaches based on the predicted mRNA secondary structure

Assessment of the sedative effect of various anesthetics in Coregonus Peled (Gmelin, 1789) in aquaculture

The sedative effect of four anesthetic agents in whitefish was studied. It is shown that the effect of anesthetics causes a number of consistent behavioral and physiological reactions in fish, reflecting the change in the state of their body. For most technological fish-breeding processes, it is necessary for fish to stay in a state of muscle relaxation while maintaining respiratory rhythm. These requirements are met by the sedation stage, which is observed with all types of anesthesia in peled. It has been established that the use of some of the tested drugs is incorrect in anesthesia in general in whitefish and in pelage in particular. Thus, the use of sodium thiopental is unacceptable, due to the uncontrolled suppression of the respiratory function of fish under the action of this agent. The use of lidocaine is characterized by prolonged induction, which does not correspond to the temporary norms of fish anesthesia. Among the tested drugs, propofol has sufficient anesthetic efficacy, which is confirmed by the temporary indicators of induction/ recovery, the depth and manageability of anesthesia, and low indicators of respiratory depression. Eugenol can serve as an alternative to propofol, which is cost-effective when working with mass material that requires large financial costs. In general, the choice of anesthetic and the adjustment of its doses depend on the specific task facing the fish breeder-ichthyopathologist

Editorial to the special issue in Fundamental and Applied Limnology: Biology and Management of Coregonid Fishes – 12th ISBMCF

Editorial

USSR in the post-war years: the struggle for economic independence (1945 - 1953)

Being the basis of the "Stalinist" economic policy, both due to the peculiarities of ideology and in the perspective of solving geopolitical problems, the struggle for the country's economic independence formed the post-war trajectory of the USSR. The purpose of the paper was to identify the influence of this factor on decisions taken by the Soviet leadership, both in domestic and in foreign policy. Archival materials that have become available to researchers make it possible to clarify the "Stalinist" strategy for solving the task of restoring the national economy and keeping countries of "people's democracy" in the zone of influence in the conditions of the formation of a bipolar world with an acute shortage of resources. The authors of the paper rely on a source database stored in the Russian State Archive of Socio-Political History (RGASPI), in the funds of the Central Committee of the CPSU, in the funds of V.M. Molotov and of A.I. Mikoyan. Continued work with documents in this area promises to open the curtain on the “white spots” of late Stalinism, which remain the subject of heated discussions in historiography. Moreover, it is the post-war period that allows analyzing the "Stalinist" managerial model in its most complete form. Thus, it is also important to investigate its mechanisms from the point of view of solving the problem of the effectiveness / non-effectiveness of the Soviet system

Signs of Selection in Synonymous Sites of the Mitochondrial Cytochrome b Gene of Baikal Oilfish (Comephoridae) by mRNA Secondary Structure Alterations

Studies over the past decade have shown a significant role of synonymous mutations in posttranscriptional regulation of gene expression, which is particularly associated with messenger RNA (mRNA) secondary structure alterations. Most studies focused on prokaryote genomes and the nuclear genomes of eukaryotes while little is known about the regulation of mitochondrial DNA (mtDNA) gene expression. This paper reveals signs of selection in synonymous sites of the mitochondrial cytochrome b gene (Cytb) of Baikal oilfish or golomyankas (Comephoridae) directed towards altering the secondary structure of the mRNA and probably altering the character of mtDNA gene expression. Our findings are based on comparisons of intraspecific genetic variation patterns of small golomyanka (Comephorus dybowski) and two genetic groups of big golomyanka (Comephorus dybowskii). Two approaches were used: (i) analysis of the distribution of synonymous mutations between weak-AT (W) and strong-GC (S) nucleotides within species and groups in accordance with mutation directions from central to peripheral haplotypes and (ii) approaches based on the predicted mRNA secondary structure

Complete mitochondrial genomes of Baikal endemic coregonids: omul and lacustrine whitefish (Salmonidae: Coregonus sp.)

Coregonid fishes are among the most successful groups in the subarctic, boreal, and subalpine fresh waters of the northern hemisphere. Limnetic–benthic sympatric species-pairs from two different evolutionary lineages, the North American lake whitefish (Coregonus clupeaformis species complex), and the European whitefish (Coregonus lavaretus species complex), are becoming the subject of close attention to explore the role of natural selection during the ecological speciation. Baikal endemic coregonids, limnetic omul (Coregonus migratorius), and benthic lacustrine whitefish (Coregonus baicalensis) are the only representatives of another unique lineage that has not left the lake since the divergence from the two above. Due to Pleistocene oscillations sympatric limnetic–benthic divergence has been replicated here many times within the same water body over a long geological period in contrast to both Europe and America where sympatric species-pairs are the results of post-glacial secondary-contacts between glacial isolates during the Late Pleistocene on the territory of each continent. Mitochondrial genomes encode genes that are essential for respiration and metabolism. Data on complete mitogenomes of Baikal endemic coregonids provided here will complement ongoing investigations on energy metabolism as the main biological function involved in the divergence between limnetic and benthic whitefish