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G V Glazko

Publications and source records attributed to G V Glazko.

14 recordsLinked to original sources
PubMed2004

The effect of mutations altering biogenic amine metabolism in Drosophila on viability and the response to environmental stresses.

Dopamine (DA) content, tyrosine decarboxylase (TDC) activity and survival were studied under normal and environmental stress conditions in the ste and e strains carrying ebony mutation increasing DA level and the octopamineless strain Tbetah(nM18) of Drosophila melanogaster. Wild-type strains Canton S and Oregon R, and strain p845 from which Tbetah(nM18) strain was derived were used as controls. Sexual dimorphism of TDC activity, DA content, and survival in flies of all D. melanogaster strains under study was found. Tbetah(nM18) mutation sharply reduced TDC activity in females, while ebony had no such effect. DA content and survival under heat stress in Tbetah(nM18) flies did not differ from those in the wild type. ste and e flies had drastically increased DA content under normal conditions, dramatically decreased survival under heat stress, but increased survival under starvation. DA content and survival under heat stress were also studied in the reciprocal hybrids (males) F(1) of the cross D. virilis strains 101 (wild type) and 147 with X-linked mutation, which significantly increases DA content. 147x101 males had a considerably higher DA content and lower survival than 101x147 ones. Individuals of all D. melanogaster strains under study developed the stress reaction, as judged by changes in TDC activity and DA levels. The role of biogenic amines in the stress reaction development and adaptation to environmental stresses in Drosophila is discussed. Arch. Insect Biochem. Physiol. 55:55-67, 2004.

Adaptation, Physiological↗
PubMed2001

Comparative study and prediction of DNA fragments associated with various elements of the nuclear matrix.

Scaffold/matrix-associated region (S/MAR) sequences are DNA regions that are attached to the nuclear matrix, and participate in many cellular processes. The nuclear matrix is a complex structure consisting of various elements. In this paper we compared frequencies of simple nucleotide motifs in S/MAR sequences and in sequences extracted directly from various nuclear matrix elements, such as nuclear lamina, cores of rosette-like structures, synaptonemal complex. Multivariate linear discriminant analysis revealed significant differences between these sequences. Based on this result we have developed a program, ChrClass (Win/NT version, ftp.bionet.nsc.ru/pub/biology/chrclass/chrclass.zip), for the prediction of the regions associated with various elements of the nuclear matrix in a query sequence. Subsequently, several test samples were analyzed by using two S/MAR prediction programs (a ChrClass and MAR-Finder) and a simple MRS criterion (S/MAR recognition signature) indicating the presence of S/MARs. Some overlap between the predictions of all MAR prediction tools has been found. Simultaneous use of the ChrClass, MRS criterion and MAR-Finder programs may help to obtain a more clearcut picture of S/MAR distribution in a query sequence. In general, our results suggest that the proportion of missed S/MARs is lower for ChrClass, whereas the proportion of wrong S/MARs is lower for MAR-Finder and MRS.

Animals↗
PubMed2001

[Interaction of hormones in controlling reproductive function of Drosophila females under stressful conditions is genetically determined].

The effect of heat stress (38 degrees C) on the content of octopamine (OA) and 20-hydroxyecdysone (20HE) was studied under normal and stressful conditions in adult flies of Drosophila virilis lines contrasting in the level of the juvenile hormone (JH). The wild-type flies (line 101) exhibited a pronounced sex dimorphism for the content of both OA and 20HE, which was substantially lower in this line than in flies of the mutant line 147. The level of both hormones increased in flies of line 101 exposed to heat stress, whereas it remained unchanged in flies of line 147 under the same conditions. The effect of heat stress on the level of JH metabolism and fertility was also studied in D. melanogaster wild-type lines and lines carrying mutations in genes responsible for OA and DA syntheses. In octopamineless females of the T beta hnM18 line and in females of the Ste line characterized by a doubled content of DA, JH degradation differed from normal: it was increased in both young and mature T beta hnM18 females, while decreased in young and increased in mature Ste flies. Fertility was substantially lower in the Ste than in the wild-type line. Flies of all of the D. melanogaster lines produced a stress response; however, in mutant lines, both fertility and stress reactivity of the systems controlling JH metabolism differed significantly from that of the wild-type lines. The role of JH, 20HE, OA, and DA interaction in regulation of Drosophila reproduction under stressful conditions is discussed.

Animals↗
PubMed2000

Computer prediction of sites associated with various elements of the nuclear matrix.

Attachment regions of the eukaryotic chromosomal DNA to the nuclear scaffold/matrix (S/MARs) participate in various important cellular processes. However, no obvious characteristics common for these nucleotide sequences have been revealed, except that S/MARs are non-coding sites containing putative regulatory elements and binding sites of DNA-topoisomerase II. Heterogeneity among S/MARs can be caused by a variety of biological factors. In this paper, the accuracy of two S/MARs prediction programs, MAR-Finder (Singh, Kramer and Krawetz, 1997) and ChrClass (Glazkov, Rogozin and Glazko, 1998) are compared and it is concluded that both programs can be recommended for analysis of eukaryotic genomes. However, results of their prediction should be interpreted with caution since estimation of prediction accuracy of both programs needs further analysis. Problems of S/MARs prediction are illustrated on several examples of human protein-coding genes, repeated elements and the beta-globin locus from different mammalian species. Results of our analysis suggest that the proportion of missed S/MARs is lower for ChrClass, whereas the proportion of wrong S/MARs is lower for MAR-Finder (a default set of parameters).

Animals↗
PubMedDate not supplied

The Wilhelmine E. Key 2001 Invitational Lecture. Estimation of divergence times for a few mammalian and several primate species.

Statistical methods for estimating divergence times by using multiprotein gamma distances are discussed. When a large number of proteins are used, even a small degree of deviation from the molecular clock hypothesis can be detected. In this case, one may use the stem-lineage method for estimating divergence times. However, the estimates obtained by this method are often similar to those obtained by the linearized tree method. Application of these methods to a dataset of 104 proteins from several vertebrate species indicated that the divergence times between humans and mice and between mice and rats are about 96 and 33 million years (MY) ago, respectively. These estimates were obtained by assuming that birds and mammals diverged 310 MY ago. Similarly application of the methods to the protein sequence data from primate species indicated that the human lineage separated from the chimpanzee, gorilla, Old World monkeys, and New World monkeys about 6.0, 7.0, 23.0, and 33.0 MY ago, respectively. In this case the use of two calibration points, that is, the divergence time (13 MY ago) between humans and orangutans and between primates and artiodactyls (90 MY ago) gave essentially the same estimates.

Animals↗
PubMedDate not supplied

[The mutational spectra of gene p53 in different types of tumors].

The comparative analysis of the frequencies of nucleotide exchanges in mutational spectra of gene p53 (5-8 exons) between germline cancer-prone families (Li-Fraumeni syndrome), between somatic mutations in the tumors of different histogenesis and cell lines, obtained from them, was carried out. The nucleotide positions with high level of mutation events (mutational "hot spots"), typical for germline mutational spectra, tissue-specific patterns of their disappearing and appearing of new ones in solid tumors in vivo, nearly complete absence of "hot spots" in lymphomas and cell lines in vitro were revealed. The obtained results allowed to suggest, that one of the leading factor controlling hot-spots distribution in 5-8 exons of gene p53 is the specificity of cell division conditions in vivo and in vitro.

Base Sequence↗
PubMedDate not supplied

[Context organization of mRNA 5'-untranslated regions of higher plants].

Computer analysis of nucleotide sequences of 5'-untranslated regions (5'-UTR) of higher plants mRNA adopted from the EMBL nucleotide sequence databank was carried out. It was demonstrated that the average nucleotide frequencies of the leader sequences and adjacent regions of basal promoters are similar, whereas introns and 3'-UTR have a higher content of T and a lower content of C. A particular 5'-UTR contextual feature is a misbalance in the content of complementary nucleotides; probably a stable secondary structure adversely affects the translation properties of the leader sequence. About 20% of 5'-UTR contain AUG triplets, which is twice the earlier estimate. Considered are the properties of leader open reading frames (uORF), the possible causes of their high content in 5'-UTRs of eukaryotic mTNAs, and correlations between the features of uORFs and of the protein-encoding sequence of the gene. It is demonstrated that in effectively translated mRNAs the leader AUG triplets are more frequently located in a nonoptimal context, whereas terminating codons of uORFs more frequently exist in the optimal one. A hypothesis is put forward that the efficiency of termination at the uORF stop codon might substantially interfere with the mRNA translation activity.

5' Untranslated Regions↗
PubMedDate not supplied

[The heterogeneity of the cytogenetic variability in the bone marrow cells of laboratory and wild rodents in the exclusion zone of the Chernobyl Atomic Electric Power Station].

Analysis of the characters of cytogenetic variabilities and correlative interrelations between them revealed the group specificities of karyotype instability in bone marrow cells of some lines of laboratory and of wild mice under the conditions of increased radionuclide pollution in the Chernobyl zone. The complex correlative interrelations between the frequencies of cytogenetic anomalies and the character of cell division (the number of metaphases, binucleated leukocytes per 1000 cells) were observed. The obtained data indicate the stimulatory influence of chronic low doses of ionizing radiation on the manifestation of spontaneous mutagenesis, which has own genotype specific characteristics.

Animals↗
PubMedDate not supplied

[The characteristics of the chromosomal level of variability in mice].

The analysis of the order of chromosome involving to interchromosome associations by the type of Robertsonian translocation (RB) in 28 cell populations in relation with three factors: their origin from different mouse lines (CBA/Ca, C3H/He, C57BL/6, BALB/c), direction of cytodifferentiation (fibroblasts and leucocytes) and the stage of its disruption (minimal, maximal and medial tumorigenicity) was carried out. The influence of all three factors on the frequencies of individual chromosome involving in RB was revealed.

Animals↗
PubMedDate not supplied

[Experimental and calculated spectra of the amplicons UBC-85 and UBC-126 (RAPD-PCR)].

The comparative analysis of experimental amplification spectrum in 13 Ungulata species and counting ones in DNA sequences of different taxa in GenBank (mammalian, other vertebrate, invertebrate, viruses, prokaryote) with the uses of RAPD-PCR primers UBC-85 and UBC-126 was carried out. The particularities of the distribution of amplicons' frequencies in experimental and counting spectrums were revealed, for some of them the similar increased frequencies in mammalian and prokaryotic species were observed.

Animals↗
PubMedDate not supplied

[Interlocus associations and their variability in cattle].

The results of analysis of interloci associations between two pairs of syntenic loci (transferrin and ceruloplasmin, receptor for vitamin D and kappa-casein) and two non-syntenic ones (amylase-1 and post-transferrin 2) in two cattle groups of Red Steppe breed (infected and uninfected by bovine leukosis virus) and in two groups of Black-and-White Holsteins (from relatively "pure" zone and from the 10 km zone of Chernobyl NPP) were presented. It is found that "linkage disequilibrium" between loci is observed independent of their synteny. The data obtained allowed the authors to suppose, that the interloci associations are rather controlled by different factors of artificial and natural selection than by the genetic linkages between genes.

Alleles↗
PubMedDate not supplied

[The interrelations between karyotypic stability and interchromosomal associations in mammalian cells].

The interchromosome associations between heterologous chromosomes (for the type of Robertsonian translocations); frequencies of the association between individual chromosomes (identified by G-bands) and mouse line pecularities, the directions of cytodifferentiation, the stages of cell neoplastic transformation in cell populations of various origin have been estimated. The presence of interrelations between individual chromosome associations and genetic and cytological cell characteristics with the use of different mathematical methods of analysis has been revealed.

Animals↗