[Evidence for evolutionary changes in ontogeny: paleontological, comparative-morphological, and molecular aspects].

It has been noted that the integration of modern data of paleontology, comparative morphology, developmental biology, and molecular genetics forms the basis for understanding the mechanisms of evolutionary transformations of ontogeny. Paleontological and morphological evidence of the evolutionary changes in ontogeny are considered based on the data of cell and molecular biology and developmental genetics. It is shown that reorganizations of gene regulatory cascades (primarily Hox genes) play a key role in the evolution of the axial organization of animals and modifications of the limb structure of metazoans, whereas the emergence and development of new types of structures was apparently determined by the emergence of new populations of stem cells in embryogenesis (for example, neural crest cells in the evolution of vertebrates).

[Influx of Ca2+ via Car1.3 calcium channels in satellite cells of muscle fibers in rats ].

Voltage-dependent L-type Cav1.3 channels have been detected in satellite cells localized to muscle fibers. It was established that the action of carbachol, which activates nicotinic acetylcholine receptors and causes cell membrane to depolarize, resulted in the activation of these channels. In addition, verapamil and amlodipine, selective L-type calcium channel blockers, suppressed extracellular calcium influx into the cytoplasm. It was noted that in a calcium-free medium, carbachol had no influence on the concentration of calcium in the cytoplasm of satellite cells, whereas adrenaline induced calcium efflux from intracellular stores. In addition, calcium influx into the cytoplasm was not suppressed by verapamil and amlodipine under the action of adrenaline and noradrenalin in a medium with calcium, and an ICI- 118551 blocker of ß2-adrenoreceptros significantly decreased the increase in the concentration of calcium in the cytoplasm.

[Lactate dehydrogenase from the tetraploid weatherfish Misgurnus fossilis during temperature adaptation: determination of structural differences in two forms of the enzyme by molecular modeling methods].

A structural analysis of two lactate dehydrogenase M4 protein forms has been performed. These structures are the protein products of two lactate dehydrogenase gene (LDH-A) copies in the weatherfish Misgurnus fossilis genome after thermal adaptation (acclimation) to 5 degrees C and 18 degrees C. The localization of three earlier identified amino acid substitutions (Gly214Val, Leu304Ile, Asp312Glu) has been determined, and the molecular dynamics simulation and computer modeling of two forms of the enzyme from skeletal muscles LDH-M4 have been carried out. After molecular dynamics trajectory calculations carried out at 5, 18, and 25 degrees C, the intersubunit distances for all structures used in calculations have been determined. It has been found that the Gly214Val substitution localized in the intersubunit region leads to a new intersubunit interaction, which plays a role in the stabilization of tetrameric enzyme structure after the adaptation to 18 degrees C.

[The expression of genes encoding the voltage-dependent L-type Ca2+ channels in proliferating and differentiating C2C12 myoblasts of mice].

Votage-dependent L-type Ca+ channels of the C2C12 line myoblasts of mice have been studied at the stage of proliferation and 24 h after the beginning of differentiation. The expression of genes Cacna1s, Cacna1S, Cacna1d, and Cacna1f, which encode channel forming subunits alpha1S, alpha1C, alph1D, and alpha1F, respectively, has been assessed. The expression of genes Cacna2d and Cacn1g, which encode the alpha2, delta, and gamma regulatory subunits, has been studied as well. For the first time, the expression of Cacnald, which is typical for nerve cells, units, has been revealed in proliferating myoblasts, whereas in differentiating mononuclear myoblasts the expression of this gene was significantly decreased. On the contrary, the low level of expression of Cacnal IS, which encodes the specific alpha1S channel forming subunit of skeletal muscles, has been observed in proliferating myoblasts, whereas in differentiating mononuclear myoblasts it has been shown to increase multifold. No considerable changes in expression of Cacna2d and Cacn 1g have been revealed in proliferating and differentiating myoblasts. No traces of expression of Cacna1c and Cacna1f have been revealed in myoblasts.

[Adaptive specific features of energy metabolism in fish ontogenesis].

A review of data on the pattern of change of the intensity of oxygen consumption during early ontogenesis of different fish species (rainbow trout, loach, zebrafish, carp, and grass carp) is provided. It has a similar pattern: this index increases in the period of embryonic and larval development and, after passing of larvae to an active feeding, it begins to gradually decline. This dynamics is determined by specific features of an increase in the rate of oxygen uptake and body weight in the course of early stages of fish ontogenesis. For determining optimal temperature conditions of development, a method of total (for a definite stage of development) oxygen uptake was suggested, which makes it possible to determine minimal energy expenditures necessary for the process of a particular stage of embryogenesis to take place. Analysis of temperature dependence of kinetic properties of enzymes with reference to the Michaelis constant (Km) for lactate dehydrogenase demonstrated that minimal Km, corresponding to maximal enzyme-substrate affinity, for embryos of different fish species differs in correspondence with differences in temperature conditions of development of these species in nature. For embryos of one species developing at changing temperature conditions (salmonids), this index changes in accordance with a temperature drift in nature.

[Dynamics of energy metabolism in ontogenesis of striped shield bug (Graphosoma lineatum L.) and cabbage moth (Mamestra brassicae L.)].

Dynamics of growth and oxygen consumption during ontogenesis of insects with direct (striped shield bug Graphosoma lineatum L.) and indirect (cabbage moth Mamestra brassicae L.) development have been compared. The correlation between a character of energy metabolism alteration and peculiarities of development of the insects has been shown. Cyclic decrease of oxygen consumption during molt and sharp dropping during metamorphosis have been observed in insects with indirect development. The decrease of oxygen consumption has been observed in insects with direct development only during molts. The coefficient a of allometric dependence of oxygen consumption on body weight of imago for cabbage moth was two times higher than that for striped shield bug.

[Expression of the MyoD and m-cadherin genes in the myogenic precursor cell culture isolated from muscles of rats at different stages of ontogenesis].

Comparative analysis of expression of the MyoD gene and m-cadherin in the myogenic precursor cells isolated from rats' muscular tissue on the 20th-21st day of embryogenesis, on the third to fifth day of postnatal development, and from adult animals was carried out. No significant differences in expression of the @MyoD@[ital] gene were observed. Nevertheless, we found that in contrast to myogenic cells isolated from postnatal muscular tissues, in the subpopulation of myoblasts isolated from embryonic tissues on the 20th-21st day of embryogenesis cells that were more progressive with respect to differentiation prevailed. These cells demonstrate little proliferative activity alongside with expression of m-cadherin, the protein responsible for cytoadherence, and, as a consequence, a higher rate of differentiation.

[Regulation of Ca2+ influx in proliferating and differentiating myoblasts of mice with participation of L-type Ca2+ channels].

The basic mechanisms of regulation of Ca2+ influx in proliferating and differentiating myoblasts, in culture have been studied. The presence of L-type Ca2+ channels in proliferating myoblasts has been shown for the first time. The influx of Ca2+ through these channels was shown to be regulated by the adrenergic system. The influx of Ca2+ through L-type Ca2+ channels after the activation of the adrenergic system by the addition of adrenaline in comparison with the contribution of reticular stocks exhausted by ATP in calcium-free medium was estimated. It was shown that the Ca2+ influx in proliferating myoblasts is regulated by beta-2 adrenergic receptors whose action is mediated by adenylate cyclase through L-type calcium channels. In differentiating myoblasts, the Ca2+ influx on the activation of the adrenergic system was essentially lower than in proliferating cells. It was found that the maximum influx of Ca2+ may be reached by the exhaustion of reticular stocks.

[Differences in the Ca2+ signaling in proliferating and differentiating myoblasts in mice].

Specific features of Ca2+ -signaling in proliferating and differentiated C2C12 myoblasts have been studied. It was shown that the system of Ca2+ -signaling is reduced in proliferating myoblasts: the intracellular ATP-regulated stock is insignificant, the buffer protein is absent or present in minimum quantities in endoplasmic reticulum, and the entry of Ca2+ is not registered when its endocellular stocks are exhausted. The formation of the Ca -signaling system occurs during the initial stages of differentiation (within eight to ten hours after transfer of cell to differentiation medium). During this period, the buffer protein is accumulated, and the entry of Ca begins. During the initial stages of myoblast differentiation, the voltage-dependent entry of Ca2+ also appears. It was also shown that the stock of in mitochondria makes an insignificant contribution to increase in Ca2+ concentration in the cytoplasm.

[Correlation of ontogenetic and evolutionary processes in view of achievements of modern genetics: role of gene duplication].

I.I. Schmalhausen's concept about the interrelation of individual and historical development is analyzed from the positions of modern developmental biology and molecular genetics. The role of gene duplication in evolutionary, ontogenetic, and adaptable processes is discussed. The data on mechanisms of functional diversification of duplicated genes (exon-intron structural changes and point mutations) in these processes are submitted. The modern synthesis outlook in developmental biology is regarded.

[Activation of reconstructive processes in rat tissues under the action of radiofrequency current with a periodic impulse mode of modulation].

The action of a current in the radio frequency range with a periodic impulse mode of modulation on the activation of recovery processes in the skin and skeletal muscles has been studied. The action of a radio frequency current with a power of 1 W, as opposed to that of the weaker action (0.1 W) and stronger (4 W) action, leads to the activation of recovery processes in the skin and skeletal muscles. Recovery processes are manifested in the increase in proliferation and activation of angiogenesis in the skin, and also in formation of new muscle fibers. Recovery processes in muscles are accompanied by activation and migration of satellite cells of muscle tissue in the zone of action of the radio frequency current.

[Analysis of expression of heavy myosin chains during in vitro differentiation of satellite cells and myoblasts derived from rat skeletal muscles].

Differentiation of cultured myogenic progenitor cells (satellite cells and mononucleated myoblasts) derived from hindlimb muscles of rat embryos and newborn animals was studied. Immunocytochemical methods and PCR analysis revealed expression of heavy myosin chains at the earliest stages of myogenesis (in mononucleated myoblasts). Expression of the gene encoding the embryonic form of myosin and a low level of expression of the gene encoding perinatal myosin in cultured progenitor cells derived from embryonic muscles was detected by PCR. Cells derived from muscles of newborn animals also expressed these two myosin forms, though at a lower level. The progenitor cells derived from muscles of rat embryos and newborn animals were found to express myosin 2a, which is characteristic of fast-twitch definitive muscle fibers.

[Specific features of satellite cells and myoblasts at different stages of rat postnatal development].

A cell culture consisting mainly of satellite cells and mononuclear myoblasts was derived from femoral muscles of infant (aged 3-7 days) and adult rats. Satellite cells identified by expression of the specific marker Pax7 accounted for approximately 80% of the isolated cell fraction. Mononuclear myoblasts represented by proliferating and postmitotic cell pools were identified immunocytochemically by the expression of markers Ki67 and desmin. Differentiation of satellite cells and myoblasts in the culture depended on the concentration of Ca2+ in the culture medium (F12 with different Ca2+ concentrations or DMEM). Differentiation of myogenic cells manifested in myoblasts fusion, formation of myotubes, and expression of myosin in myofibrils was observed only in the medium with a high Ca2+ concentration (2 mM). Satellite cells and myoblasts from the muscles of newborn and adult rats did not differ noticeably in their capacity for differentiation.

[Comparative study of superoxide dismutase and glutathione peroxidase activity in embryos and skeletal muscles of adult fish].

The activity of the antioxidant enzymes superoxide dismutase and glutathione peroxidase in loach and sturgeon embryogenesis as well as in red and white skeletal muscles of loach was studied. The specific activity of cytoplasmic and mitochondrial forms of superoxide dismutase in developing sturgeon embryos was higher than in loach embryos, which may be due to oxygen conditions under which these species develop in nature. A similar dependence was also observed for the activity of glutathione peroxidase in embryos of these fish species. A comparative study of specific superoxide dismutase activity in loach and sturgeon embryos and in loach skeletal muscles showed that the activity of cytoplasmic superoxide dismutase is maximum in red and white muscles and minimum in loach embryos, whereas the activity of the mitochondrial form of this enzyme is maximum in red skeletal muscles.

[Muscle satellite cells and regulation of recovery potential of the muscles].

Major aspects of the biology of muscle satellite cells are reviewed: the identification, origin in early development, mechanisms of self-renewal mediated by asymmetric divisions, content in different muscle types and in different ontogenetic stages, role of control genes of the Pax family (in particular, Pax7) and their products in proliferation control, and involvement of growth factors (HGF, FGF, IDF, and TGF-beta) in the activation of these cells after muscle damage. The characteristics of the early stages of myogenic differentiation of activated satellite cells along the pathway similar to muscle formation in embryonic development are discussed.

[Retrospective analysis of influence of environmental conditions on growth parameters of White Sea edible mussels Mytilus edulis].

Retrospective analysis of influence of environmental conditions on growth parameters of White Sea edible mussels Mytilus edulis has been done by measurements of successive annual rings on shell surface. Analysis by non-linear criterion and Bertalanffy's growth equation allows to deduce that the best environmental condition for edible mussels growth was in 1999 (population from Kastyan island region) and in 2001 (population of Malaya Pir-guba region). The worst one was in 1998 for both populations.

[Comparative analysis of growth of edible mussel Mytilus edulis from different White Sea regions].

Growth properties were studied in edible mussel Mytilus edulis from different biotopes of the Kandalaksha Bay in the White Sea. Growth curves of the mussel shell were approximated by the von Bertalanffy equation. The highest growth rate, primarily dependent on hydrological conditions, was observed in mussels from the Chupa Bay (Levin Navolok fishery), while the lowest rate was observed in mussels from the Umba region (Turn Cape, Murmansk Region). Allometric relationships of the mussel shell were determined. Analysis of the relationship between the maximum width/convexity and their length demonstrated that this relationship is described by a single allometric equation for mussels from the Umba region, which indicates the homogeneity of this population. For mussels from the Chupa Bay, this relationship cannot be described by a single equation, which points to the population heterogeneity. For 90% mussels from this region, the shell width/convexity ratio ranged from 0.5 to 0.9; while for the remaining 10%, it ranged from 0.9 to 1.15.

[Comparative structural analysis of myosin light chains and gene duplication in fish].

Origin and structure of myosin light chain (MLC) proteins have been studied by comparative analysis of fish mlc1, mlc2, and mlc3 genes encoding MLC1, MLC2, and MLC3, respectively. The exon-intron structure of these genes has been analyzed in zebrafish Danio rerio, loach Misgurnus fossilis, fugu Takifugu rubripes, and Nile puffer Tetraodon fahaka. We propose that mlc1 and mlc3 are homologues genes originated by fish-specific whole genome duplication (paralogs). This is supported by high sequence similarity between mlc1 and mlc3 as well as by the exon-intron structure of these genes and their localization on different chromosomes. Exons 2 to 5 of mlc1 and mlc3 are highly conserved and have similar splicing sites. A paralog gene of mlc2 resulting from a similar duplication event has been identified in zebrafish genome. Expression of mlc2 paralog is limited to the larval stages of Danio rerio and to regenerating tissues of the adult fish. There is a possibility that the paralog of mlc2 encodes larval myosin light chain protein (larval MLC) previously reported in a number of fish species.

[Ontogenetic and phylogenetic analysis of myosin light chain proteins from skeletal muscles of loach Misgurnus fossilis].

mRNAs of all three types of myosin light chain proteins are expressed in skeletal muscles of both larval and adult stages of loach Misgurnus fossilis (Cobitidae) and these proteins are encoded by different genes (mlc1, mlc2, and mlc3). No difference was revealed between transcripts from larval stage and adult fish for all three mlc proteins. Our approach (RT-PCR with fish-specific mlc1, mlc2, and mlc3 primers) failed to reveal the larval form of myosin light chain protein found previously by protein electrophoresis of loach fry muscle extract. Comparative analysis of the protein structure shows high homology of MLC1 and MLC3 proteins sharing a large EF-hand calcium-binding domain. Phylogenetic analysis of MLC1 from skeletal muscles of fish and other vertebrate species is concordant with the traditional phylogeny of the group. Within the Teleostei, loach MLC1 had the highest homology with other Cyprinidae, and least with Salmonidae fishes.