Molecular Genetic Markers of Intra- and Interspecific Divergence within Starfish and Sea Urchins (Echinodermata).

A fragment of the mitochondrial COI gene from isolates of several echinoderm species was sequenced. The isolates were from three species of starfish from the Asteriidae family (Asterias amurensis and Aphelasterias japonica collected in the Sea of Japan and Asterias rubens collected in the White Sea) and from the sea urchin Echinocardium cordatum (family Loveniidae) collected in the Sea of Japan. Additionally, regions including internal transcribed spacers and 5.8S rRNA (ITS1 - 5.8S rDNA - ITS2) were sequenced for the three studied starfish species. Phylogenetic analysis of the obtained COI sequences together with earlier determined homologous COI sequences from Ast. forbesii, Ast. rubens, and Echinocardium laevigaster from the North Atlantic and E. cordatum from the Yellow and North Seas (GenBank) placed them into strictly conspecific clusters with high bootstrap support (99% in all cases). Only two exceptions - Ast. rubens DQ077915 sequence placed with the Ast. forbesii cluster and Aph. japonica DQ992560 sequence placed with the Ast. amurensis cluster - were likely results of species misidentification. The intraspecific polymorphism for the COI gene within the Asteriidae family varied within a range of 0.2-0.9% as estimated from the genetic distances. The corresponding intrageneric and intergeneric values were 10.4-12.1 and 21.8-29.8%, respectively. The interspecific divergence for the COI gene in the sea urchin of Echinocardium genus (family Loveniidae) was significantly higher (17.1-17.7%) than in the starfish, while intergeneric divergence (14.6-25.7%) was similar to that in asteroids. The interspecific genetic distances for the nuclear transcribed sequences (ITS1 - 5.8S rDNA - ITS2) within the Asteriidae family were lower (3.1-4.5%), and the intergeneric distances were significantly higher (32.8-35.0%), compared to the corresponding distances for the COI gene. These results suggest that the investigated molecular-genetic markers could be used for segregation and identification of echinoderm species.

[Morphology of gametes in sea urchins from Peter the Great Bay, Sea of Japan].

The fine structure of the gametes in six sea urchin species of the Sea of Japan was studied. The spermatozoons in Strongylocentrotus nudus, S. intermedius, Echinocardium cordatum, Scaphechinus mirabilis, Sc. grizeus and Echinarachnius parma are species-specific. The conical head and symmetrically disposed ring-shape mitochondrion are common to regular sea urchin sperm cells. S. nudus is characterized by the bulb-shaped head of the zoosperm; S. intermedius, by a bullet-shaped one. The zoosperm spearhead and small amount of postacrosome material are common to irregular sea urchins; the sperm width: length ratio varies for different species, with the highest for Sc. mirabilis. The zoosperm of Sc. griseus is characterized by two lipid drops in the cell center. Asymmetrical mitochondrion disposal is usual for E. parma. Actin filaments are found in the postacrosome material in the zoosperm of cordiform sea urchins. The differences in the fine structure of zoosperm in eurybiont species Ech. cordatum inhabiting the Sea of Japan and coastal areas of the Northeast Atlantic may bear record to the complex existence of species Ech. cordatum. The fine structure of zoosperm is unique for each of the studied families, Strongylocentrotidae, Scutellidae, and Loveniidae. The eggs of all the species are characterized by vitelline and tremelloid membranes. The vitelline membrane is formed by cytoplasm protrusions; the area between them is filled with fubrillary material. The tremelloid membrane is formed by fubrillary material associated with apical parts of microvilli of the vitelline membrane. The irregular sea urchins Sc. griseus, Sc. mirabilis and E. parma are characterized by chromatophores situated in the tremelloid membrane, with the highest abundance in Sc. mirabilis.

Optical and nonlinear optical properties of sea glass sponge spicules.

Originating in nature, the combination of spongin protein with silicon dioxide extracted from seawater by silicatein protein presents a natural nanocomposite material of unique optical and mechanical properties. Mechanically, it combines the elasticity of protein with the flexibility and durability of silica. The light propagation inside spicules of glass sponges is of substantial interest for developing novel elements for photonics applications. The glass sponge spicules have remarkable light guiding properties. Our experimental research on passing laser pulses through spicules of Hyalonema sieboldi and Pheronema sp. reveals a concentration of guided light in the paraxial region. The multi-layer cladding of glass sponge spicules produced by nature has an obvious analogy with some contemporary artificial microstructured optical fibers. Our researches have shown that the core diameter and cladding layers thickness of the spicules of H. sieboldi and Pheronema sp. glass sponges are appropriate for causing photonic bandgaps in the infrared, visible, and ultraviolet wavelength regions. This enables singlemode waveguide and Bragg light propagation regimes in the spicules and provides exciting prospects of using them for the development of fundamentally new integrated optical elements based on peculiar waveguide properties of such structures, e.g., single-way waveguides (optical diodes) with increased mode field diameter and unique frequency and dispersion characteristics. Also, we have investigated the dynamics of propagation of intensive ultra-short pulses with durations T (0) < 40 fs through various patterns of spicules. Comparative analysis of the spectra of the output signals has shown that chromatic dispersion in spicules is considerably reduced, which can be explained by waveguide dispersion prevailing over material dispersion because of the multilayer structure of the cladding.

[The influence of ultrasound and constant magnetic field on gametes, zygotes, and embryos of the sea urchin].

The influence of constant magnetic field, power 7 T, and ultrasound, frequency 2, 4 and 8 MHz, on gametes, fertization, embryos and larvae of the sea urchin was studied. It was shown that magnetic field breaks the process of the gamete fusion but does not influence gametes, embryos, and larvae. Ultrasound impairs the motility of spermatozoa and larvae, prevents the fertilization, and breaks the embryonic development. It is assumed that the effect of the magnetic field is connected with the response of the cortical cytoskeleton, which consists of bundles of actin microfilaments. The rearrangement of the cortical cytoskeleton occurs during the first 20 minutes after the contact of sperm with the egg. Also there is effect of magnetic fields on calcium ions, which are liberated during the first seconds after gamete contact. The effect of the ultrasound is explained by a small increase in water temperature and cavitation process, which break celluar structures.

[Polymerization of myorod, a surface protein of thick filaments of molluscan smooth muscle].

The study is concerned with the polymerization of myorod, a protein from thick filaments of molluscan smooth muscles, which is an alternative product of the gene of myosin heavy chains. The dependences of the properties and polymer structure of myorod on the conditions of its formation were investigated. It was shown that myorod loses the ability to form viscous polymers after proteolytic removal of the unique sequence. It was supposed that the specificity of polymerization of myorod are determined by its unique N-terminal sequence.

[Comparative study of the physico-chemical properties of chitosans with varying degree of polymerization in neutral aqueous solutions]. / Sravnitel'noe izuchenie fiziko-khimicheskikh svoistv khitozanov razlichnoi stepeni polimerizatsii v neitral'nykh vodnykh rastvorakh.

The physicochemical properties of chitosan samples with high (130 kD) and low (30 kD) molecular masses in neutral aqueous solutions (pH 6.0) were studied by the methods of high-speed and equilibrium sedimentation, viscosimetry, and NMR and UV spectroscopies. Differences in the hydrodynamic characteristics of the samples were revealed. It was found that low-molecular-weight chitosan represents flexible linear macromolecules which undergo conformational changes upon temperature increase. The high-molecular-weight chitosan forms more rigid asymmetric structures whose conformation does not vary significantly with temperature increase. It was found that the high-molecular-weight chitosan has a higher constant of binding to the anionic dye tropeoline 000-II, which can be explained by different conformations of their macromolecules in solution.

[Characteristics of oogenesis in the Barents sea sponge Leucosolenia complicata]. / Osobennosti ovogeneza u Barentsevomorskoi gubki Leucosolenia compli cata.

Ovogenesis of the Barents sea sponge Leucosolenia complicata Mont. having asconoid canal system was studied at light (using histochemical methods) and ultrastructural levels. It has been established that the reproduction period "arranges" for autumn-winter season. The ovogenesis lasts for approximately two months. Grand accroissement is the longest stage of ovogenesis, lastiing in L. complicata from the end of Sptember to the middle of November. At this stage ovocytes lose their amebic movement, which coincides with the beginning of nurse cell formation. The nurse cells are derived from choanocytes. The choanocytes contacting with the ovocyte surface lose the collar and flagellum, grow in size and transform into nurse cells. Any cell of nurse-cell complex is capable of seizing a spermium and being transformed in situ into a carrier-cell. The specific role of nurse-cell complex is to synthesize sudanophilic (lipid) granules for the carrier cell and ovocyte. In the whole, a weak phagocytic activity of ovocytes, is characteristic of the ovogenesis of L. complicata. During vitellogenesis the ovocyte synthesises endogenic mucopolysaccharide granules from oligosaccharides originated from the mesohyl. Lipid granules pass to the ovocyte from nurse cells. Ribosomal RNAs are accumulated as a result of the own activity of nucleolus-nucleus apparatus of the ovocyte.

[The role of different neuromediator systems in regulating the reproduction of memory engrams in rats]. / Rol' razlichnykh neiromediatornykh sistem v reguliatsii vosproizvedeniia éngramm pamiati u krys.

In experiments on 796 white rats the role was studied of various neurotransmitter systems (choline-, adreno-, serotonin-, dopamine-, and GABA-ergic) in regulation of processes of engrams reproduction, determined by tests of conditioned passive- and active-defensive reactions in comparison with changes of spontaneous motor activity and oriented reaction. Correlations are analyzed between the changes of animals behavioural reactions in conditions of pharmacological control of activity of the studied neurotransmitter systems.

[Morphogenetic role of the cortex in the development of twins in sea urchins]. / Morfogeneticheskaia rol' korteksa v razvitii bliznetsov u morskogo ezha.

The dynamics of development of Strongylocentrotus nudus sea urchin twins has been studied after centrifugation at 2,000 g for 5 min and incubation in hypotonic medium after fertilization till formation of the first cleavage furrow. Cortex rigidity was found to correlate with the frequency of twins occurrence. The largest amount of twins forms after centrifugation and hypotonic treatment for the first 1-6 min of zygote development. The twins may be obtained at 25-40 min of development by centrifugation in the presence of cytochalasin B (1 micrograms/ml). Morphogenetic role of cortex in development of sea urchin twins has been discussed.

[Role of adrenergic mechanisms in regulating memory engram retrieval and energy metabolism in the brain structures of the rat]. / Rol' adrenergicheskikh mekhanizmov v reguliatsii vosproizvedeniia éngramm pamiati i énergeticheskogo obmena v strukturakh golovnogo mozga krys.

In conditions of stimulation of adrenergic mechanisms with ephedrine, there was an improvement of the memory engrams reproduction (MER). Blockade of the alpha-adrenergic system by pyrroxan more expressively impeded reproduction of a passive defensive habit in comparison with the action of a beta-adrenolytic, the obsidan. Stimulation of MER processes was accompanied by a parallel activation of glucose-6-phosphate- and 6-phosphategluconatedehydrogenases of pentose path in the tissues of the frontal area of the cerebral cortex and pons Varolii. Blockade of alpha-adrenoreceptors suppressed the activity of the given enzymes in the same structures, while the obsidan suppressed the dehydrogenases of the pentose path only in the frontal zone of the neocortex.

[Ultrastructural changes in the mitochondria of Retzius' neuron exposed to hydrocortisone]. / Izmeneniia ul'trastruktury mitokhondrii neirona Retsiusa pri deistviem gidrokortizona.

The ultrastructure of the Retzius cell (gigantic neurone) mitochondria of the medical leech was investigated. After seven repeated injections of hydrocortisone into the coelomic cavity, the transformation of laminar cristae of mitochondria into tubule-vesiculated structures was discovered. A question of correlation between the structure and function independently of the systematical position of the organism is discussed.

[Sarcoplasmic actin in muscle cells of ambulacral tubes of the sea star]. / Sarkoplazmaticheskii aktin v myshechnykh kletkakh ambulakral'nykh nzhek morskoi zvezdy.

Protein solubilized in large quantities in solutions of low ionic strength, when myofibril-like preparations were isolated from ambulacral tube, was shown to be actin. When gelation of sarcoplasmic proteins occurs a gel consisting of actin microfilaments bundles is formed. The factor which inhibits actin polymerization is liberated during gel formation. The aggregate substance of sarcoplasmic actin under cell ionic conditions may be determined by binding with this factor.

[Cortical reaction of the eggs of the mussel, Crenomytilus grayanus]. / Kortikal'naia reaktsiia iaits midii Crenomytilus grayanus.

The extrusion of the contents of cortical granules was found in the places of contact of spermatozoa with the egg surface upon fertilization of the mussel eggs. Not all cortical granules broke down, a great number of them is preserved in the developing embryo cells. The possible mechanism and importance of this phenomenon are discussed.