67 research outputs found

    Biotechnological methods as a tool for efficient sugar beet breeding

    Get PDF
    Here we consider aspects of the application of biotechnological methods to rapid creation, propagation, and maintenance of plants with improved or new traits in sugar beet breeding. The results of the works carried out in these fields by the Federal State Budgetary Scientific Institution "The A.L. Mazlumov All-Russia Research Institute of Sugar Beet” are reviewed. A close association between morphological and physiological changes in in vitro cultured organs and tissues, on the one hand, and breeding traits, on the other hand, which allows the development of experimental systems for non-amphimictic plant reconstruction is shown. The influence of in vitro growth conditions on haploid cells of unfertilized sugar beet ovules in the course of obtaining doubled haploid lines with high degree of homozygosity and maintenance of valuable breeding properties is considered. As compared to common inbreeding, this method shortens the time for development of homozygous material from 10-12 to 3-5 years, which is of great importance for speeding-up the breeding process. The results of studies on the culturing of mature sugar beet zygotic embryos based on in vitro selective systems have made it possible to improve the adaptive potential of plants and to provide complex resistance to environmental stress factors. Strict selection under abiotic stress conditions allowed creation of sugar beet isogenic lines with tolerance of drought, salinity, and soil acidity. It is shown that the proposed original design of mass-scale microclonal in vitro reproduction and deposition of elite plants as components of highly productive hybrids can be used to obtain seeds of uniform high-quality breeding material. The technologies developed by biotechnological methods are a topical and innovative direction of inquiry, since the application of these techniques to sugar beet breeding will promote obtaining of competitive hybrids with a set of commercially valuable traits. The combination of biotechnology methods, including tissue culture, and traditional breeding techniques is expected to provide an opportunity to obtain a new starting material to develop domestic varieties and hybrids of new generation with heterosis effect and a wide resistance spectrum persisting across generations

    MODELING OF GNATOMETRIC INDICES DEPENDING ON PARAMETERS OF BASAL CRANIAL STRUCTURES IN BOYS AND GIRLS WITH ORTHOGNATHIC BITE

    Get PDF
    For the possibility of forming an objective basis for determining the diagnosis and creating the ultimate goal of orthodontic treatment, it is necessary to have a clear understanding of the individual variables of the basic metric characteristics of certain individual parameters of bone structures and soft facial tissues. The aim of the study – to construct and analyze the regression models of gnatometric indices, depending on the parameters of basal cranial structures in boys and girls with orthognathic bite. Materials and Methods. Teleroentgenography and computed tomography studies were performed on 38 boys (aged from 17 to 21) and 55 girls (aged from 16 to 20 years) who had a physiological bite as close as possible to orthognathic. The construction of regression models of gnatometric indices, depending on the parameters of basal cranial structures, was carried out in the licensed package "Statistica 6.0". Results and Discussion. As a result of the regression analysis conducted in the boys with orthognathic occlusion, the following models of gnatometric parameters were constructed depending on the parameters of the basal cranial structures: effective length of the maxilla = - (16.11+1.01)×distance Se_N + 0,45×magnitude of the base of the maxilla + 0.28×distance S_E (determination factor is 0.612); length of the upper jaw = - (15.42+0.50) ×distance Se_N + 0.50×the size of the base of the upper jaw (the determination coefficient is equal to 0.550); angle SND = 107.8 – 0.47×H-angle + 0.39×magnitude of the base of the upper jaw – 0.38×distance S_E (determination coefficient is equal to 0.502); distance S_L = (13.05+1.51) ×distance Se_N – 0.87×H-angle – 0.86×distance S_E + 0.63×magnitude of the base of the upper jaw (determination coefficient is 0.626). Conclusions. Of the 43 possible regression models of gnatometric indices, depending on the parameters of the basal cranial structures in boys with orthognathic occlusion, only 4 valid models with a determination coefficient greater than 0.5 were constructed, namely, effective length of the upper jaw, maxilla length, SND angle and distance S_L. In girls with orthognathic bite, models with a determination coefficient greater than 0.5 are not built at all

    Temperature effects in low-frequency Raman spectra of corticosteroid hormones

    Get PDF
    Experimental Raman spectra of the corticosteroid hormones corticosterone and desoxycorticosterone are recorded at different temperatures (in the range of 30–310 K) in the region of low-frequency (15–120 cm−1) vibrations using a solid-state laser at 532.1 nm. The intramolecular vibrations of both hormones are interpreted on the basis of Raman spectra calculated by the B3LYP/6-31G(d) density functional theory method. The intermolecular bonds in tetramers of hormones are studied with the help of the topological theory of Bader using data of X-ray structural analysis for crystalline samples of hormones. The total energy of intermolecular interactions in the tetramer of desoxycorticosterone (−49.1 kJ/mol) is higher than in the tetramer of corticosterone (−36.9 kJ/mol). A strong intramolecular hydrogen bond O21-H⋯O=C20 with an energy of −42.4 kJ/mol was revealed in the corticosterone molecule, which is absent in the desoxycorticosterone molecule. This fact makes the Raman spectra of both hormones somewhat different. It is shown that the low-frequency lines in the Raman spectra are associated with skeletal vibrations of molecules and bending vibrations of the substituent at the C17 atom. The calculated Raman spectrum of the desoxycorticosterone dimer allows one to explain the splitting and shift of some lines and to interpret new strong lines observed in the spectra at low temperatures, which are caused by the intermolecular interaction and mixing of normal vibrations in a crystal cell. On the whole the calculated frequencies are in a good agreement with the experimental results

    Mammalian Stem Cells Reprogramming in Response to Terahertz Radiation

    Get PDF
    We report that extended exposure to broad-spectrum terahertz radiation results in specific changes in cellular functions that are closely related to DNA-directed gene transcription. Our gene chip survey of gene expression shows that whereas 89% of the protein coding genes in mouse stem cells do not respond to the applied terahertz radiation, certain genes are activated, while other are repressed. RT-PCR experiments with selected gene probes corresponding to transcripts in the three groups of genes detail the gene specific effect. The response was not only gene specific but also irradiation conditions dependent. Our findings suggest that the applied terahertz irradiation accelerates cell differentiation toward adipose phenotype by activating the transcription factor peroxisome proliferator-activated receptor gamma (PPARG). Finally, our molecular dynamics computer simulations indicate that the local breathing dynamics of the PPARG promoter DNA coincides with the gene specific response to the THz radiation. We propose that THz radiation is a potential tool for cellular reprogramming

    Recombination between Polioviruses and Co-Circulating Coxsackie A Viruses: Role in the Emergence of Pathogenic Vaccine-Derived Polioviruses

    Get PDF
    Ten outbreaks of poliomyelitis caused by pathogenic circulating vaccine-derived polioviruses (cVDPVs) have recently been reported in different regions of the world. Two of these outbreaks occurred in Madagascar. Most cVDPVs were recombinants of mutated poliovaccine strains and other unidentified enteroviruses of species C. We previously reported that a type 2 cVDPV isolated during an outbreak in Madagascar was co-circulating with coxsackieviruses A17 (CA17) and that sequences in the 3′ half of the cVDPV and CA17 genomes were related. The goal of this study was to investigate whether these CA17 isolates can act as recombination partners of poliovirus and subsequently to evaluate the major effects of recombination events on the phenotype of the recombinants. We first cloned the infectious cDNA of a Madagascar CA17 isolate. We then generated recombinant constructs combining the genetic material of this CA17 isolate with that of the type 2 vaccine strain and that of the type 2 cVDPV. Our results showed that poliovirus/CA17 recombinants are viable. The recombinant in which the 3′ half of the vaccine strain genome had been replaced by that of the CA17 genome yielded larger plaques and was less temperature sensitive than its parental strains. The virus in which the 3′ portion of the cVDPV genome was replaced by the 3′ half of the CA17 genome was almost as neurovirulent as the cVDPV in transgenic mice expressing the poliovirus cellular receptor gene. The co-circulation in children and genetic recombination of viruses, differing in their pathogenicity for humans and in certain other biological properties such as receptor usage, can lead to the generation of pathogenic recombinants, thus constituting an interesting model of viral evolution and emergence

    A comprehensive study of albumin solutions in the extended terahertz frequency range

    No full text
    Sensitivity of the THz frequency range to the solutions of biomolecules originates from the decrease of absorption and dispersion of water in its bound state. Correct measurement and interpretation of the THz spectra of water-containing samples is still a challenging task because the reliable relaxation model for such spectra is not well established. The transmission and the attenuated total internal reflection geometries data were combined for precise analysis of the spectra of the aqueous solutions of bovine serum albumin within the range 0.05–3.2 THz. We compare the concentration dependencies of the dielectric function at “low,” “middle,” and “high” frequency and do not confirm an anomalous increase in absorption for concentrations below 17 mg/mL published by other teams

    A comprehensive study of albumin solutions in the extended terahertz frequency range

    No full text
    Sensitivity of the THz frequency range to the solutions of biomolecules originates from the decrease of absorption and dispersion of water in its bound state. Correct measurement and interpretation of the THz spectra of water-containing samples is still a challenging task because the reliable relaxation model for such spectra is not well established. The transmission and the attenuated total internal reflection geometries data were combined for precise analysis of the spectra of the aqueous solutions of bovine serum albumin within the range 0.05–3.2 THz. We compare the concentration dependencies of the dielectric function at “low,” “middle,” and “high” frequency and do not confirm an anomalous increase in absorption for concentrations below 17 mg/mL published by other teams
    corecore