Selective effect of the duration of the critical temperature period on some allozyme loci of Atlantic salmon Salmo salar L. (Salmonidae)

Genetic structure of juvenile fish from the populations of the Atlantic salmon Salmo salar inhabiting the rivers of Murmansk oblast, Arkhangelsk oblast, and Karelia, as well as of juveniles from hatcheries was examined at five allozymic loci: aspartate aminotransferase (AAT-4*), isocitrate dehydrogenase (IDHP-3*), iditol dehydrogenase (IDDH-2*), esterase D (ESTD*), and malic enzyme (MEP-2*). High genetic differentiation of both natural and "hatchery" juvenile fish was revealed. It was demonstrated that the gene pool of juveniles at three of the five loci tested was to a considerable degree formed by natural selection. In this case, the role of limiting factor was played by the duration of critical temperature regime in the rivers. The differentiation factors for juveniles from nature were not established, however, their clusterization pattern pointed to a possible role of natural selection in this process.     

Variability of microsatellite loci of Greenland cod <Emphasis Type="Italic">Gadus ogac</Emphasis> Richardson 1836: Comparison with other species of <Emphasis Type="Italic">Gadus</Emphasis> genus (Gadidae)

Comparative analysis of variability of seven microsatellite loci—Gmo3, Gmo-G12, Gmo-G18, Gmo19, Gmo34, Gmo35 and Pgmo32—was performed for the Greenland cod Gadus ogac, Pacific cod G. macrocephalus, Atlantic cod G. morhua, and White Sea cod G. morhua marisalbi. High genetic identity was observed between the Greenland cod and Pacific cod (I = 0.9520). Pair analysis of genetic differentiation was performed on the studied microsatellite loci according to θ (analogue of F _ST). The Greenland cod differed significantly from the Pacific, Atlantic, and the White Sea cod; however, the differentiation level varied. The lowest value was observed for the pair Greenland cod-Pacific cod (0.123), and the highest levels were registered for the pairs Greenland cod-Atlantic cod (0.605) and Greenland cod-White Sea cod (0.535).     

Adsorptive immobilization of rhodococcal cells in hydrophobized derivatives of wide-pore polyacrylamide cryogel

Adsorption of Rhodococcus ruber cells on columns with polyacrylamide cryogel (CryoPAAG) partially hydrophobized by different quantities (0.2, 1, and 5 mol %) of chemically grafted n-dodecane residues has been studied. The adsorption capacity (1.1 x 10(9) cells/g) of gel carrier for rhodococcal cells and the optimal content (1 mol %) of hydrophobizing groups were determined. The respirometric method showed the high catalytic activity and functional stability of immobilized bacterial cells. Respiratory activity of immobilized rhodococci in the presence of a model mixture of oil hydrocarbons exceeded the respective parameter for free cells by 12-17%. Viability of rhodococcal cells adsorptionally fixed in hydrophobized cryoPAAG was maintained at a level of 93-95% after a half-year period of storage. The results may be used for development of immobilized biocatalyst for directed transformation of hydrocarbon compounds and biological purification of oil-polluted water.     

A novel deconvolution method for modeling UDP-N-acetyl-D-glucosamine biosynthetic pathways based on 13C mass isotopologue profiles under non-steady-state conditions

This article is a response to Wang and Luo. See correspondence article http://www.biomedcentral.com/1741-7007/10/30/ [WEBCITE] and the original research article http://www.biomedcentral.com/1741-7007/9/24 [WEBCITE].     

Isolation of ES-Like Lines of Common Voles of the Genus Microtus from Blastocysts and Germ Cells and as a Result of Fusion of Somatic Cells with Mouse Embryonic Stem Cells

Three and four independent cell lines with limited pluripotency were obtained from the inner cell mass cells of blastocysts and primordial germ cells of common voles, respectively. The results of cytogenetic analysis suggest that all these lines originated from the embryos of F₁ Microtus rossiaemeridionalis × M. arvalis males and had a great number of near-triploid cells already during the early passages. The cells of these lines, like those of the inner cell mass, were characterized by the alkaline phosphatase activity. Nine independent cell lines were obtained as a result of hybridization of the mouse embryonic stem cells and vole splenocytes: eight lines and one line from hybridization with the M. kirgisorum and M. rossiaemeridionalis splenocytes, respectively. The cells of these lines expressed some properties of embryonic stem lines had a chromosome complement similar to the sum of two initial diploid sets of the mouse and vole.     

Caryophyllane Thiols,Vinyl Thioethers,Di‐ and Bis‐Sulfides: Antioxidant and Membrane Protective Activities

Caryophyllane thioterpenoids were synthesized in 23 – 81% yields. The antioxidant properties of the obtained compounds in various model systems were found. It was revealed that 4,5‐epoxycaryophyll‐9‐ylmethanethiol has the greatest antioxidant activity. The isomerism of sesquiterpenic fragments was shown to have a significant effect on the biological activity of the compounds.     

Genetic differentiation and the problems of conservation of masu salmon (<Emphasis Type="Italic">Oncorhynchus masou</Emphasis> Brevoort, 1856 (Pisces: Salmonidae)) populations

This study focuses on the strategy for the conservation of masu salmon, Oncorhynchus masou, in the northern part of the species range (via the masu populations in Sakhalin Oblast), based on data of its population structure. It is shown that masu populations that inhabit different rivers genetically differ from each other in allele frequencies at microsatellite markers. In the Naiba River basin, at least two genetically distinct masu populations exist: in the upper reaches and in a tributary, the Bolshoy Takoy River. The masu populations on Iturup Island significantly differ from those on Sakhalin Island; within Sakhalin, the masu salmon from the Chernaya River in the southwestern part of the island is genetically distinct from the southeastern Sakhalin and Aniva Bay populations. The genetic diversity of Iturup populations is substantially lower than that on Sakhalin, probably due to their small sizes. The measures for the conservation and recovery of masu salmon populations should be based primarily on their own genetic resources, or, in the case of a lack of spawners, on the base populations of their ecological/geographical region. In the latter case, masu populations of large rivers can be considered as base ones: for southeastern Sakhalin, this is masu salmon of the Naiba River; for Aniva Bay, this is masu salmon of the Lyutoga River. Transplantation of fish, fertilized eggs, or any other genetic material from a population that is different genetically and inhabits the waters with different ecological gradients should be strongly restricted. The formosan masu salmon from Taiwan Island is studied as an example of a strict genetic isolate.     

Divergence of the seasonal races of chum salmon, <Emphasis Type="Italic">Oncorhynchus keta</Emphasis> Walbaum, 1792, in the Amur and Poronai rivers: Ecology,genetics, and morphology

The chum salmon of the Amur River (the mainland part of the Far East) and the Poronai River (Terpeniya Bay, Sakhalin Island) are historically related to one another, as the drainage basins of these rivers are the remnants of a formerly single river system, the Paleoamur, which existed when Sakhalin Island was a part of the continent. Both river populations of chum salmon consist of the early-run and late-run ecological forms (seasonal races), which are also referred to as the summer and autumn races. They are reproductively isolated from each other due to their spawning at different times and in different types of spawning grounds. To assess the direction, pattern, and degree of divergence between these chum salmon races in the both river fragments since the Paleoamur, it is necessary to compare them using two types of traits: selectively neutral DNA markers and morphological and physiological traits, variations in which may have an adaptive value. For this, we have studied chum salmon from both rivers in terms of microsatellite DNA markers, body counts and measurements, body weight, and fecundity. Both in the Amur River and in the Poronai River, the autumn race of chum salmon prevails over the summer race in body length and weight, fecundity, number of pyloric caeca, and several other meristic traits. The intra-basin differences between the races are much more pronounced in the Amur chum salmon. The inter-race differences in microsatellites are also greater in the Amur chum salmon compared to the Poronai chum salmon. Using microsatellites, three levels of differentiation have been revealed: (1) between the basins of the Amur and Poronai rivers, (2) between the races within each of the river basins, (3) and between population samples within each race of each basin. A hypothesis is proposed that the currently existing races of chum salmon in the Amur and Poronai rivers have evolved since the breakup of the Paleoamur, and the intra-basin divergence of the races started in the Amur River earlier than in the Poronai River. An analysis of our own data and the published data suggests that the adaptation of the seasonal races of chum salmon to the conditions of their spawning grounds is determined by a complex of morphological and physiological traits, including the number of pyloric caeca, which is an adaptive and highly heritable trait associated with the incubation temperature of the water.