The size of the eggs of the Argentine anchovy,Engraulis anchoita (Hubbs & Marini) in relation to the season of the year and to the area of spawning*

The problem of egg size variations in the Argentine anchovy Engraulis anchoita has been studied in relation to the different seasons of the year and to the different spawning centres within the geographical area. It has been stated that there exist significative differences in egg dimensions between the northern and the southern spawning centre of the reproduction area. Taking into account other biological characteristics of the anchovy from both centres it is suggested that these variations could indicate that the spawning stock is divided into two main genetic groups. It has been found that the average size of anchovy eggs decreases as the spawning season progresses.     

Isolation of the R'his plasmids of Vibrio cholerae

V. cholerae strain VT5104 capable of donor activity in conjugation has been constructed by the genetic technique based on plasmid RP4::Mucts62 integration into V. cholerae chromosome due to plasmid homology with Mucts62 inserted into the chromosome. The gene for histidine synthesis has been mobilized and transferred into the recipient cells from VT5104 donor. The conjugants obtained are able to efficiently transfer his+ gene included into the plasmid structure in conjugation with eltor recipient. Thus, the constructed strain VT5104 generates R' plasmids carrying V. cholerae chromosomal genes.     

Identification of the hatching factor of the barnacle as the novel eicosanoid 10,11,12-trihydroxy-5,8,14,17-eicosatetraenoic acid

Barnacle egg hatching fator which is released into the mantle cavity where the egg masses are brooded and stimulates embryonic musculature resulting in hatching and liberation of the larvae into the sea has been isolated in a purified form from a common barnacle . Derivatised hatching factor has been analysed by GC-MS and identified as 10,11,12-trihydroxy-5,8,14,12-eicosatetraenoic acid, a novel eicosanoid probably formed from endogenous eicosapentaenoic acid (20:5w3). Hatching factor activity is the first specific physiological function to be established for this type of compound.     

The protein import and assembly machinery of the mitochondrial outer membrane

The process of mitochondrial protein import has been studied for many years. Despite this attention, many processes associated with mitochondrial biogenesis are poorly understood. Insight into one of these processes, assembly of beta-barrel proteins into the mitochondrial outer membrane, will be discussed. This review focuses on recent data that suggest that assembly of beta-barrel proteins into the outer mitochondrial membrane is dependent on a newly identified protein complex termed the sorting and assembly machinery (SAM complex). Members of the SAM complex have been identified in both eukaryotic and prokaryotic organisms, suggesting that the process of beta-barrel assembly into membranes has been conserved through evolution.     

Formation of a system of exogenous tangential fibers in layer I of the cerebral cortex in the ontogeny of the dog]

During pre- and postnatal periods, development of nuclear projections of the diencephalon into the cortical layer I has been studied in dogs by means of silver nitrate impregnation after Cajal. It has been stated that after the 5th week of the intrauterine development a great number of fibres from the diencephalon, through the germ of the cortical lamina, begin penetrating into the layer 1 within the areas of the paleocortex, the island, the subicular field of the archicotex, the presubicular and entorhinal cortex. A little less fibres have been revealed in the sensomotor and temporoentorhinal areas on the convex surface of the frontal lobe and on the medial surface of the occipital lobe. At the places of their penetrating into the cortical layer 1, by the time of birth, the fibres have sprouted up thickness of the whole area of the hemisphere.     

Evolution of the visual cortex and the emergence of symmetry in the Acheulean techno-complex

Several recent studies have examined human evolution with reference either to the symmetry of Acheulean tools or brain structure but although these investigations have been informative they have not generally taken into account the psychology of perception in relation to recent insights into neural pathways of the visual brain. Similarly, the interest in symmetry has largely been restricted to understanding tool morphology that has ignored research on how this property might be processed by the brain that could help provide new insights into cognitive evolution. The purpose of this paper is therefore to bring these diverse approaches together in an effort to assimilate the various findings so that a fuller understanding of the cognitive profile of hominins during the early to Middle Pleistocene can be achieved.     

Distribution of Alu repeats along the human genome: formation of clusters and features of insertion regions

The contextual analysis of nucleotide sequences of 22 Alu repeats arrangement regions in the human genome has been carried out and some of their peculiarities have been revealed. In particular, the occurrence of marked and statistical non-random homology between the repeats and the regions of their integration has been shown. A mechanism of choosing the Alu repeats insertion regions in the genome has been suggested taking into account these peculiarities. Using a sample of the 80 human Alu repeats sequences peculiarities of these repeats location within the genome has been investigated. A tendency to the formation of Alu repeats clusters in various regions of the genome was revealed. A range of possible mechanisms on such Alu clusters emergence is considered. On the basis of the data obtained an "attraction" mechanism, according to which integration of Alu repeats into the definite region of the genome increases the insertion probability of other Alu repeats into the same region, are proposed.     

The effect of alpha-tocopherol and ionol on the physical structure of the membranes of rat liver microsomes under conditions of antioxidant insufficiency

Physiochemical conformity of the alpha-tocopherol interaction with hepatic microsomal membranes has been studied by means of fluorescent probes (pyrene and 1-anilinonaphthalene-8-sulphonate). The microsomal membrane microviscosity is shown to sharply decrease under conditions of the antioxidant deficiency with vitamin E expelled into animals normalizes microviscosity, but feebly influences the microsomal surface charge. Microcalorimetry has been used to establish that penetration of tocopherol into microsomal membranes was accompanied by the exothermic effect.     

Penetration of the peptide lactaptin into human cancer cells

Lactaptin, a human milk protein with a molecular weight of 8.6 kDa, is a fragment of human ?casein, which has cytotoxic activity toward mammalian cancer cells in vitro. RL2 is a recombinant analogue of lactaptin, which induces the apoptosis of human cancer cells in culture and suppresses the tumor growth in vivo. It has been shown earlier that RL2 penetrates into both human cancer and nonmalignized cells and binds to cytoskeletal structures. In this process, it induces the apoptosis of cancer cells and does not diminish the viability of normal cells. The mechanism of the penetration of RL2 into human cancer cells has been studied by flow cytometry and fluorescence microscopy using the inhibitors of different endocytosis pathways. It has been shown that RL2 penetrates into cells partly through lipid raft-mediated dynamin-independent pinocytosis and partly through direct penetration across the plasma cell membrane. An analysis of the primary structure of RL2 and the mechanism of its penetration into the cell suggests that it can be assigned to the class of cell-penetrating peptides.     

Identification of the hatching factor of the barnacle Balanus balanoides as the novel eicosanoid 10,11,12-trihydroxy-5,8,14,17-eicosatetraenoic acid

Barnacle egg hatching factor which is released into the mantle cavity where the egg masses are brooded and stimulates embryonic musculature resulting in hatching and liberation of the larvae into the sea has been isolated in a purified form from a common barnacle Balanus balanoides. Derivatised hatching factor has been analysed by GC-MS and identified as 10,11,12-trihydroxy-5,8,14,12-eicosatetraenoic acid, a novel eicosanoid probably formed from endogenous eicosapentaenoic acid (20:5w3). Hatching factor activity is the first specific physiological function to be established for this type of compound.     

Inherited disorders of ion transport in the intestine

Within the past year, it has been established that the gene mutated in the human disorder congenital chloride diarrhea encodes a major Cl-/HCO3- exchanger at the apical membrane of gut epithelial cells. A major apical Na+/H+ exchanger has also been identified. New insight into metal ion absorption has been gained, and several new transporters without cognate diseases have been cloned.     

Studies on viral fusion peptides: the distribution of lipophilic and electrostatic potential over the peptide determines the angle of insertion into a membrane

The oblique insertion of type 1 viral fusion peptides into the cell membrane of the host cell has been shown previously to be an essential element of viral fusion. The actual physical explanation of the cause of the oblique insertion has been the subject of speculation. In this study the physical properties of the fusion peptide surface have been determined computationally and compared to the tilt angles determined both experimentally and by the use of molecular dynamics. It has been shown that the relationship between the distribution of lipophilic potential over the peptide surface and the peptide geometry control the tilt angle of the peptide in a biomimetic DMPC bilayer whereas the depth of penetration into the bilayer appears to be determined by the electrostatic potential and hydrogen bonding at the C-terminus.     

A persistent model of the reptation movement of a DNA molecule

By using a persistent model of the movement of a DNA molecule, the penetration of the DNA molecule into a cell has been described. The method enables one to estimate the time and the rate of passage of the DNA molecule into the cell nucleus. The effect of the curvature of the molecule on its longitudinal movement has been studied. The results obtained can be applied to characterize long chain molecules.     

Electro-insertion of xeno-glycophorin into the red blood cell membrane

The electroporation technique, with field strengths slightly below the critical value Ec for electroporation of red blood cells (RBC), enables the insertion of xeno-proteins into the RBC membrane without damaging the cells. The electro-insertion has been used to insert biotinylated human glycophorin into human RBC membrane and human glycophorin into murine RBC membrane. Binding anti-human glycophorin antibody (10F7) to the murine RBC bearing human glycophorin indicates extracellular orientation of inserted glycophorin. Insertion of about 10(5) glycophorin molecule per cell has been estimated by whole cell ELISA.     

Knowledge-based modeling of the serine protease triad into non-proteases.

The Asp-His-Ser triad of serine proteases has been regarded, in the present study, as an independent catalytic motif, because in nature it has been incorporated at the active sites of enzymes as diverse as the serine proteases and the lipases. Incorporating this motif into non-protease scaffolds, by rational design and mutagenesis, might lead to the generation of novel catalysts. As an aid to such experiments, a knowledge-based computer modeling procedure has been developed to model the protease Asp-His-Ser triad into non-proteases. Catalytic triads from a set of trypsin family proteases have been analyzed and criteria that characterize the geometry of the triads have been obtained. Using these criteria, the modeling procedure first identifies sites in non-proteases that are suitable for modeling the protease triad. H-bonded Asp-His-Ser triads, that mimic the protease catalytic triad in geometry, are then modeled in at these sites, provided it is stereochemically possible to do so. Thus non-protease sites at which H-bonded Asp-His-Ser triads are successfully modeled in may be considered for mutagenesis experiments that aim at introducing the protease triad into non-proteases. The triad modeling procedure has been used to identify sites for introducing the protease triad in three binding proteins and an immunoglobulin. A scoring function, depending on inter-residue distances, solvent accessibility and the substitution potential of amino acid residues at the modeling sites in the host proteins, has been used to assess the quality of the model triads.     

The use of transposons for the mutagenesis of R. phaseoli and R. japonicum

Plasmid pSUp2011 has been used to transfer transposon Tn5 into the cells of R. japonicum 110 and R. phaseoli 693. Transposition of Tn5 into the chromosomes of R. japonicum and R. phaseoli has been demonstrated,resulting in isolation of auxotrophic and symbiotic mutants of both strains. The frequencies of selected auxotrophic mutations have reached 4% in R. japonicum 110 and 0.6% in R. phaseoli 693. Streptomycin resistance gene locating on Tn5 has been found to be phenotypically expressed in R. japonicum 110 and R. phaseoli 693 cells.