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61.
Gheorghe I. Chiriac Larisa I. Andronic Valeriu V. Bujoreanu Liliana I. Marii 《Central European Journal of Biology》2006,1(3):386-398
The evidence of increased crossing over rate in tomato hybrids infected with TAV (Tomato aspermy virus), PVX (Potato virus
X), TMV (Tobacco mosaic virus), TMV+PVX indicates the recombinogenic effect of viral infection. Cytological studies of the
early diakinesis in healthy and virus-infected tomato revealed significant changes in chiasma number and position. The most
significant changes were established for bivalents with two interstitial chiasmata and with one terminal and one interstitial.
The data obtained indicate redistribution of the chiasmata position and induction of additional exchanges. The virus-induced
recombination is segment-specific and depends on the host plant genotype, virus infection and the interaction between them. 相似文献
62.
Titov LP Zakerbostanabad S Slizen V Surkova L Taghikhani M Bahrmand A 《Biotechnology journal》2006,1(12):1447-1452
The aim of this study was to investigate the frequency, location and type of rpoB mutations in Mycobacterium tuberculosis isolated from patients in Belarus. Tuberculosis cases are increasing every year in Belarus. Moreover, resistance to anti-tuberculosis drugs, especially to rifampicine, has increased. In this study, 44 rifampicine-resistance M. tuberculosis clinical isolates (including multidrug-resistant isolates) were subjected to DNA sequencing analysis of the hypervariable region (hot-spot) of the rpoB gene originating from different geographical regions in Belarus. Sixteen different types of mutations were identified. The most common point mutations were in codons 510 (47.7%), 526 (45.5%), 523 (40.86%) and 531 (29.5%). Eleven isolates (27.7%) carried one mutation and 23 (52%), 7 (16%), 3 (7%) of isolates carried 2, 3 and 4 mutations, respectively. A characteristic, prominent finding of this study was high frequency of multiple mutations in different codons of the rpoB gene (27.7%) and also the detection of unusual types of mutations in the 510 codon, comprising CAG mutations (deletion or changing, to CTG, CAC or CAT). In our study, the change TTG in codon 531 was found in 92% of isolates and the change TGC in 8% of isolates. A TAC change in codon 526 was not found, but the GAC change was found in all isolates. Isolates of M. tuberculosis isolated in Belarus were characterized by the wide spectrum of the important mutations and might belong to the epidemic widespread clones. 相似文献
63.
Minasian SM Gevorkian ES Adamian TsI Ksadzhikian NN 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2006,92(7):817-826
Dynamics psychological and cadriohemodynamical parameters and activity regulators mechanisms of a rhythm of heart of students in current of academic year is studied. It is shown, that process of adaptation of students to an academic load is accompanied by the periods of recession and a pressure parameters of hemodynamic, activity regulators mechanisms of a rhythm of heart and parameters of state of health, activity and mood. The periods of the highest pressure of physiological systems of an organism of students are the beginning of the first semester and the examination period. The adaptive changes of investigated parameters occurred in the course the academic year. 相似文献
64.
Svetlana A. Romanenko Polina L. Perelman Natalya A. Serdukova Vladimir A. Trifonov Larisa S. Biltueva Jinhuan Wang Tangliang Li Wenhui Nie Patricia C.M. O’Brien Vitaly T. Volobouev Roscoe Stanyon Malcolm A. Ferguson-Smith Fengtang Yang Alexander S. Graphodatsky 《Mammalian genome》2006,17(12):1183-1192
The laboratory mouse (Mus musculus, 2n = 40), the Chinese hamster (Cricetulus griseus, 2n = 22), and the golden (Syrian) hamster (Mesocricetus auratus, 2n = 44) are common laboratory animals, extensively used in biomedical research. In contrast with the mouse genome, which was
sequenced and well characterized, the hamster species has been set aside. We constructed a chromosome paint set for the golden
hamster, which for the first time allowed us to perform multidirectional chromosome painting between the golden hamster and
the mouse and between the two species of hamster. From these data we constructed a detailed comparative chromosome map of
the laboratory mouse and the two hamster species. The golden hamster painting probes revealed 25 autosomal segments in the
Chinese hamster and 43 in the mouse. Using the Chinese hamster probes, 23 conserved segments were found in the golden hamster
karyotype. The mouse probes revealed 42 conserved autosomal segments in the golden hamster karyotype. The two largest chromosomes
of the Chinese hamster (1 and 2) are homologous to seven and five chromosomes of the golden hamster, respectively. The golden
hamster karyotype can be transformed into the Chinese hamster karyotype by 15 fusions and 3 fissions. Previous reconstructions
of the ancestral murid karyotype proposed diploid numbers from 2n = 52 to 2n = 54. By integrating the new multidirectional chromosome painting data presented here with previous comparative genomics
data, we can propose that syntenies to mouse Chrs 6 and 16 were both present and to hypothesize a diploid number of 2n = 48 for the ancestral Murinae/Cricetinae karyotype. 相似文献
65.
MOTIVATION: A Robot Scientist is a physically implemented robotic system that can automatically carry out cycles of scientific experimentation. We are commissioning a new Robot Scientist designed to investigate gene function in S. cerevisiae. This Robot Scientist will be capable of initiating >1,000 experiments, and making >200,000 observations a day. Robot Scientists provide a unique test bed for the development of methodologies for the curation and annotation of scientific experiments: because the experiments are conceived and executed automatically by computer, it is possible to completely capture and digitally curate all aspects of the scientific process. This new ability brings with it significant technical challenges. To meet these we apply an ontology driven approach to the representation of all the Robot Scientist's data and metadata. RESULTS: We demonstrate the utility of developing an ontology for our new Robot Scientist. This ontology is based on a general ontology of experiments. The ontology aids the curation and annotating of the experimental data and metadata, and the equipment metadata, and supports the design of database systems to hold the data and metadata. AVAILABILITY: EXPO in XML and OWL formats is at: http://sourceforge.net/projects/expo/. All materials about the Robot Scientist project are available at: http://www.aber.ac.uk/compsci/Research/bio/robotsci/. 相似文献
66.
Background
Membrane proteins compose up to 30% of coding sequences within genomes. However, their structure determination is lagging behind compared with soluble proteins due to the experimental difficulties. Therefore, it is important to develop reliable computational methods to predict structures of membrane proteins. 相似文献67.
Tatiana Sitnikova Ellinor Michel Yulia Tulupova Igor Khanaev Valentina Parfenova Larisa Prozorova 《Symbiosis (Philadelphia, Pa.)》2012,56(3):103-110
We describe the first records of spirochetes in the gut of fourteen species of continental gastropods from a range of habitats and representing six families (Amnicolidae, Baicaliidae, Bithyniidae, Pyrgulidae, Lithoglyphidae and Benedictiidae). The bacteria were mainly found in the crystalline style sac, as has been reported in marine bivalves. The surveyed habitats include water bodies in North America and Eurasia, including deep water hydrothermal vent and gas hydrate zones in Lake Baikal. Spirochetes were present both in mature and young snails, but were not detected in embryos before hatching, indicating lateral transfer. The surveyed gastropods range in trophic strategy, including phyto-, detrito- and bacteriophagous grazers and filter feeders. Our results indicate that spirochetes are commensal in the surveyed gastropods with potential limited benefit and no detriment to the host animal. We suggest that the specialized internal habitat of the crystalline style sac in molluscs is likely to reveal unrecognized spirochete diversity that will shed new light on gastropod trophic ecology and spirochete diversity. 相似文献
68.
V Perić Mataruga M Vlahović B Janać L Ilijin M Janković Tomanić D Matić M Mrdaković 《Peptides》2012,37(1):55-62
Ghrelin is a 28-amino acid peptide that has significant effects on appetite and growth in humans and animals. The aim of this study was to examine 4th instar larvae of the pest insect Lymantria dispar L. after ghrelin treatment. Parameters included changes in nutritional indices (efficiency of conversion of ingested food, efficiency of conversion of digested food, approximate digestibility); midgut and fat body mass; total proteases, trypsin and leucine aminopeptidase activities in the midgut; number, height and width of columnar and goblet cells and their nuclei in the midgut epithelium and detection of ghrelin-like immunoreactivity in the midgut tissue. Four subpicomolar injections of ghrelin (0.3pmol) or physiological saline (control) were applied every 24h. The nutritional indices were higher in the ghrelin treated than in the control group. Ghrelin treatment was also associated with elevation of midgut mass, induced digestive enzyme activities, increased fat body mass and morphometric changes in columnar and goblet cells. This is the first report of the presence of ghrelin-like hormone in endocrine cells of an insect midgut. Such information provides additional evidence for application of this relatively simple model system in the future studies of the mechanisms underlying of digestion and energy balance in more complex organisms. 相似文献
69.
Liang J Naveed H Jimenez-Morales D Adamian L Lin M 《Biochimica et biophysica acta》2012,1818(4):927-941
We discuss recent progresses in computational studies of membrane proteins based on physical models with parameters derived from bioinformatics analysis. We describe computational identification of membrane proteins and prediction of their topology from sequence, discovery of sequence and spatial motifs, and implications of these discoveries. The detection of evolutionary signal for understanding the substitution pattern of residues in the TM segments and for sequence alignment is also discussed. We further discuss empirical potential functions for energetics of inserting residues in the TM domain, for interactions between TM helices or strands, and their applications in predicting lipid-facing surfaces of the TM domain. Recent progresses in structure predictions of membrane proteins are also reviewed, with further discussions on calculation of ensemble properties such as melting temperature based on simplified state space model. Additional topics include prediction of oligomerization state of membrane proteins, identification of the interfaces for protein-protein interactions, and design of membrane proteins. This article is part of a Special Issue entitled: Protein Folding in Membranes. 相似文献
70.
Hilde Nybom Artur Mikiciński Larisa Garkava-Gustavsson Jasna Sehic Mariusz Lewandowski Piotr Sobiczewski 《Trees - Structure and Function》2012,26(1):199-213
Fire blight (Erwinia amylovora) causes serious damage to pome fruit orchards, and identification of germplasm with heritable disease resistance is therefore
crucial. Two dominant SCAR (sequence characterised amplified region) marker alleles (AE10-375 and GE-8019), flanking a previously
identified QTL (quantitative trait locus) for resistance to fire blight on ‘Fiesta’ linkage group 7 in apple cultivars related
to ‘Cox’s Orange Pippin’, were screened on 205 apple cultivars. Both marker alleles were present in 22% of the cultivars,
indicating presence of the QTL allele for tolerance, and both were lacking in 25%, indicating homozygosity for absence of
the QTL tolerance allele. However, 33% had only the marker allele AE10-375, while 20% had only GE-8019, suggesting that some
cultivars with the dominant alleles for both of the flanking markers can carry these on separate chromosomes and may lack
the QTL allele for tolerance. In 2009 and 2010, terminal shoots of greenhouse-grown grafted trees of 21 cultivars (only 20
in 2010) were inoculated with Erwinia amylovora. ‘Idared’ (susceptible) and ‘Enterprise’ (tolerant) were included as controls. Disease severity for each cultivar was expressed
as percentage of necrosis in relation to entire length of shoot, and the ranking of cultivars in 2009 and 2010 was compared
with a Spearman rank correlation test, P < 0.01. A relationship between presence of both flanking marker alleles for tolerance and level of fire blight tolerance
was confirmed with a Mann–Whitney U-test, P < 0.01 in 2009, and P < 0.05 in 2010. A PCO (principal coordinate) analysis based on band profiles obtained with 12 SSR (simple sequence repeat)
loci produced three loose clusters, two of which contained known offspring of ‘Cox’s Orange Pippin’, and one with cultivars
that were either unrelated or had an unknown origin. Cases where DNA markers did not predict level of fire blight damage as
expected, were, however, as common among descendants of ‘Cox’s Orange Pippin’ as among apparently unrelated cultivars. Obviously
the ‘Fiesta’ LG 7 QTL has some predictive value, both for known ‘Cox’ relatives and others, but more efficient markers would
be desirable for marker-assisted selection. 相似文献