Anna Zhuk - Academia.edu (original) (raw)
Papers by Anna Zhuk
Biological Communications
Polyploidization is involved in a variety of biological processes. It is one of the principal mec... more Polyploidization is involved in a variety of biological processes. It is one of the principal mechanisms of new species formation since it provides material for gene diversification and subsequent selection. Multiple cases of polyploidization were registered in different branches of the evolutionary tree of eukaryotes. Besides its role in evolution, polyploidization affects gene expression in living cells: pathological genome duplications often happen in cancer cells. The mechanisms and consequences of polyploidization are being studied extensively. However, quantitative determination of the polyploidization rate is challenging due to its low frequency and the absence of selective genetic markers that would phenotypically distinguish between haploids and polyploids. Our work describes a robust and straightforward method for discriminating haploid and polyploid states in the yeast Saccharomyces cerevisiae, a model organism for studying different aspects of polyploidization. The measu...
Ecological genetics
Background. The alpha-test allows to detect inherited genetic changes of different types, as well... more Background. The alpha-test allows to detect inherited genetic changes of different types, as well as phenotypic expression of primary DNA lesions before the lesions are fixed by repair. Here we investigate ability of the alpha-test to detect base modifications induced by 6-N-hydroxylaminopurine (HAP) and determine frequency of inherited and non-inherited genetic changes in yeast strains treated with HAP. Materials and methods. The alpha-test is based on mating type regulation and detects cell type switch from to a in heterothallic yeast Saccharomyces cerevisiae. The frequency of mating type switching reflects level of both spontaneous and induced by a mutagen DNA instability. The alpha-test may be performed in two variants: illegitimate hybridization and cytoduction. Conducting both complementary tests and analysis of phenotypes of the illegitimate hybrids and cytoductants allows to detect the full spectrum of genetic events that lead to mating type switching, such as chromosome III...
Journal of Heredity
The Puma lineage within the family Felidae consists of 3 species that last shared a common ancest... more The Puma lineage within the family Felidae consists of 3 species that last shared a common ancestor around 4.9 million years ago. Whole-genome sequences of 2 species from the lineage were previously reported: the cheetah (Acinonyx jubatus) and the mountain lion (Puma concolor). The present report describes a whole-genome assembly of the remaining species, the jaguarundi (Puma yagouaroundi). We sequenced the genome of a male jaguarundi with 10X Genomics linked reads and assembled the whole-genome sequence. The assembled genome contains a series of scaffolds that reach the length of chromosome arms and is similar in scaffold contiguity to the genome assemblies of cheetah and puma, with a contig N50 = 100.2 kbp and a scaffold N50 = 49.27 Mbp. We assessed the assembled sequence of the jaguarundi genome using BUSCO, aligned reads of the sequenced individual and another published female jaguarundi to the assembled genome, annotated protein-coding genes, repeats, genomic variants and their...
Cancers, 2021
The authors wish to make the following corrections to this paper [...]
Supplemental materials include 11 Suppl figures - pdf-files,6 Suppl Tables, 4 pdf and 2 excel fil... more Supplemental materials include 11 Suppl figures - pdf-files,6 Suppl Tables, 4 pdf and 2 excel files Suppl Results, 2 pdf files.Supplemental Results 1. Problems with the construction of haploid yeast strains with DNA polymerase alleles reducing fitness.<i></i>Supplemental Results 2. Estimation of the probabilities of recurrent mutations in the same gene. Supplemental Table 1. Mutator effect of <i>pol2rc-</i><i>Δ</i><i>N</i> is reduced 60% in strain without the catalytic subunit of pol ζ, Rev3.Supplemental Table 2. Differences in mutant frequencies with or without UV-light irradiation in <i>pol2rc-</i><i>Δ</i><i>N</i> <i>vs</i>. wild-type strains.Supplemental Table 3. The <i>pol2rc-</i><i>Δ</i><i>N </i>elevated chromosome instability.Supplemental Table 4. (Excel file) Summary of mutations found in the course of genomic sequencing of the <i>pol2rc-ΔN...
Yeast, 2013
The alpha-test : defining the nature of mating type switching alpha -> a in heterotallic yeast... more The alpha-test : defining the nature of mating type switching alpha -> a in heterotallic yeast S. cerevisiae
Cancers, 2021
Multiple myeloma (MM) is a malignant neoplasm of terminally differentiated immunoglobulin-produci... more Multiple myeloma (MM) is a malignant neoplasm of terminally differentiated immunoglobulin-producing B lymphocytes called plasma cells. MM is the second most common hematologic malignancy, and it poses a heavy economic and social burden because it remains incurable and confers a profound disability to patients. Despite current progress in MM treatment, the disease invariably recurs, even after the transplantation of autologous hematopoietic stem cells (ASCT). Biological processes leading to a pathological myeloma clone and the mechanisms of further evolution of the disease are far from complete understanding. Genetically, MM is a complex disease that demonstrates a high level of heterogeneity. Myeloma genomes carry numerous genetic changes, including structural genome variations and chromosomal gains and losses, and these changes occur in combinations with point mutations affecting various cellular pathways, including genome maintenance. MM genome instability in its extreme is manife...
Genetics, 2021
Current eukaryotic replication models postulate that leading and lagging DNA strands are replicat... more Current eukaryotic replication models postulate that leading and lagging DNA strands are replicated predominantly by dedicated DNA polymerases. The catalytic subunit of the leading strand DNA polymerase ε, Pol2, consists of two halves made of two different ancestral B-family DNA polymerases. Counterintuitively, the catalytically active N-terminal half is dispensable, while the inactive C-terminal part is required for viability. Despite extensive studies of yeast Saccharomyces cerevisiae strains lacking the active N-terminal half, it is still unclear how these strains survive and recover. We designed a robust method for constructing mutants with only the C-terminal part of Pol2. Strains without the active polymerase part show severe growth defects, sensitivity to replication inhibitors, chromosomal instability, and elevated spontaneous mutagenesis. Intriguingly, the slow-growing mutant strains rapidly accumulate fast-growing clones. Analysis of genomic DNA sequences of these clones r...
Cancers, 2020
Recent studies on tumor genomes revealed that mutations in genes of replicative DNA polymerases c... more Recent studies on tumor genomes revealed that mutations in genes of replicative DNA polymerases cause a predisposition for cancer by increasing genome instability. The past 10 years have uncovered exciting details about the structure and function of replicative DNA polymerases and the replication fork organization. The principal idea of participation of different polymerases in specific transactions at the fork proposed by Morrison and coauthors 30 years ago and later named “division of labor,” remains standing, with an amendment of the broader role of polymerase δ in the replication of both the lagging and leading DNA strands. However, cancer-associated mutations predominantly affect the catalytic subunit of polymerase ε that participates in leading strand DNA synthesis. We analyze how new findings in the DNA replication field help elucidate the polymerase variants’ effects on cancer.
Molecular Biology, 2020
Classical views of hereditary mechanisms consider linear nucleic acids, DNA and RNA, as template ... more Classical views of hereditary mechanisms consider linear nucleic acids, DNA and RNA, as template molecules wherein genetic information is encoded by the sequence of nitrogenous bases. The template principle embodied in the central dogma of molecular biology describes the allowed paths of genetic information transfer from nucleic acids to proteins. The discovery of prions revealed an additional hereditary mechanism whereby the spatial structure is transmitted from one protein molecule to another independently of the sequence of nitrogenous bases in their structural genes. The simultaneous existence of linear (type I) and conformational (type II) templates in one cell inevitably implies their interaction. The review analyzes the current data confirming the idea that protein amyloid transformation may influence the genome stability and considers potential mechanisms of interactions between type I and type II template processes. Special attention is paid to the joint contribution of the two process to tumor "evolution" and the mechanisms of genome destabilization due to amyloid transformation of proteins in Alzheimer's and Parkinson's diseases and Down syndrome.
Frontiers in Genetics, 2017
Lada et al. APOBEC Mutations in Resting Diploid Yeast APOBEC1 behaved similar to PmCDA1. We concl... more Lada et al. APOBEC Mutations in Resting Diploid Yeast APOBEC1 behaved similar to PmCDA1. We conclude that replication, transcription, and mitotic recombination contribute to the recovered APOBEC-induced mutations in resting diploids. The mechanism is relevant to the initial stages of oncogenic transformation in terminally differentiated cells, when recombination may lead to the LOH exposing recessive mutations induced by APOBECs in cell's history and to acquisition of new mutations near original break.
![Research paper thumbnail of Impact of prionization of the Sup35 protein [PSI+] on the frequency of genetic changes, accounted in the alpha-test in yeast Saccharomyces cerevisiae](https://attachments.academia-assets.com/98368086/thumbnails/1.jpg)
](Russian Journal of Genetics: Applied Research, 2017
Amyloidogenesis in nerve tissues cause human diseases such as Alzheimer's disease, Parkinson's di... more Amyloidogenesis in nerve tissues cause human diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, and the illness of Louis Gehrig, characterized by specific neurodegenerative symptoms. The frequency of nerve cells with an abnormal number of chromosomes is increased in patients with Alzheimer's disease. However, the direct impact of prions on the genome stability has not been sufficiently investigated. In our work, we studied the impact of the [PSI+] prions on the stability of the S. cerevisiae genome using the alpha-test system.
Cell and Tissue Biology, 2017
⎯Synchronization of cell division in yeast cultures of Saccharomyces cerevisiae is widely used in... more ⎯Synchronization of cell division in yeast cultures of Saccharomyces cerevisiae is widely used in studies on regulation of eukaryotic gene expression and biochemical processes at different stages of the cell cycle. In this study, we compared the efficacy of modern widely used methodologies to achieve and assess the degree of synchronization of cell division in yeast. Based on the literature and our own data, we propose practical recommendations for synchronization of cell divisions in S. cerevisiae using chemical reagents (alpha-factor, hydroxyurea, nocodazole), and a genetic cell-cycle block (temperature-sensitive mutation cdc28-4).
![Research paper thumbnail of Sup35 prionization [PSI+] influence the frequency of the gene and chromosome mutations, accounted in the alpha-test in yeast Saccharomyces cerevisiae](https://attachments.academia-assets.com/98368035/thumbnails/1.jpg)
](Ecological genetics, 2015
Background. A lot of neurodegenerative diseases are coursed by amiloidization of proteins in nerv... more Background. A lot of neurodegenerative diseases are coursed by amiloidization of proteins in nerve tissues. In the patients brains suffered from Alzheimer’s disease the high fraction of the nerve cells with abnormal chromosome amount was revealed. There are some data showing that prion form of protein PrP may prevent chromosome segregation in mitosis. But the direct association of prionisation and genome stability was not revealed. Materials and methods. We compared the yeast S. cerevisiae strain bearing the prion form of the termination translation factor Sup35, and the strain with non-prionized Sup35 in the alpha-test system. The model of the alpha-test is based on the mechanism of mating type switching in heterothallic yeast strains. The MAT locus that controls the mating type of yeast cell can be presented by two idiomorphs: the MATalpha and MATa that determine the alpha and a cell types, correspondingly. Only two cells with opposite mating types (alpha × a) could copulate. In t...
Gigiena i sanitariia
Primary (spontaneous and externally induces) damages to genetic material frequently lead to herit... more Primary (spontaneous and externally induces) damages to genetic material frequently lead to heritable changes (gene mutations, chromosome aberrations and nondisjunction), which may cause cancer inherent and inborn diseases. It is suggested that primary damages may affect a phenotype until they are repaired or become mutations during inaccurate repair The alpha-test on the yeast Saccharomyces cerevisiae can answer the fundamental questions as the nature of primary damages that can be phenotypically manifested, their occurrence, conversion to each other and repair or conversion to heritable changes in genetic material.
Russian Journal of Genetics, 2011
The hypothesis on a relationship between the high frequency of mitotic disturbances in bone marro... more The hypothesis on a relationship between the high frequency of mitotic disturbances in bone marrow cells and the change in the activity of the S9 liver fraction containing promutagen-activating enzymes under olfactory stress in the house mouse Mus musculus has been tested. For this purpose, the effect of the pheromone 2,5-dimethylpyrazine on the frequency of mitotic disturbances in mouse bone marrow cells has been measured by the anaphase-telophase assay. The Ames test using Salmonella typhimurium has been employed to compare the capacities of the S9 liver fractions from stressed and intact mice for activating the promutagen 2-aminofluorene. It has been demonstrated that the increased frequency of mitotic disturbances in bone marrow cells induced by the pheromonal stressor in male house mice is accompanied by an increased promutagen-activating capacity of the S9 liver fraction. The model system used in the study allowed the genetic consequences of the exposure to the olfactory stressor to be estimated and the possible mechanisms of genome destabilization to be assumed.
Journal of Mathematical Sciences, 2006
In approximation theory, a number of quantities are interrelated via orthogonal transformations. ... more In approximation theory, a number of quantities are interrelated via orthogonal transformations. The revelation of these orthogonalities allows one to obtain useful relations and, in particular, to use known theorems on the Fourier coefficients. The paper considers this approach in application to the Fourier transforms of finite functions, to the best L2-approximations, and to trigonometric polynomials with coefficients in a vector space. Bibliography: 11 titles.
Journal of Mathematical Sciences, 2008
V n,2l (t) = (2l − 1)!2 2l−1 λ 2l π(n + 1) 2l−1 sin (n+1)t 2 t 2l , λ 2l = l−1 k=0 (−1) k C k 2l ... more V n,2l (t) = (2l − 1)!2 2l−1 λ 2l π(n + 1) 2l−1 sin (n+1)t 2 t 2l , λ 2l = l−1 k=0 (−1) k C k 2l (l − k) 2l−1 , be the generalized Jackson-Vallée-Poussin integral. Denote Km(f) = Km,ϕ(f) = sup 0<v<∞ ωm(f, v) ϕ(v). The paper studies the quantity Km(f −D n,r,l (f)). The general results obtained are applicable to other approximation methods. Bibliography: 11 titles.
Journal of Mathematical Sciences, 2007
In the paper, a generalization of a known theorem by Hardy and Young is obtained; a formula inter... more In the paper, a generalization of a known theorem by Hardy and Young is obtained; a formula interrelating the integral of a 2π-periodic function over the period with the integral over the entire axis is established; new approximation characteristics for functions belonging to saturation classes of continuity modules of different orders for the spaces Lp of periodic functions are provided, and some issues concerning approximation, in the uniform metric, of continuous periodic functions even with respect to each of their variables and having nonnegative Fourier coefficients are considered. Bibliography: 17 titles.
Biological Communications
Polyploidization is involved in a variety of biological processes. It is one of the principal mec... more Polyploidization is involved in a variety of biological processes. It is one of the principal mechanisms of new species formation since it provides material for gene diversification and subsequent selection. Multiple cases of polyploidization were registered in different branches of the evolutionary tree of eukaryotes. Besides its role in evolution, polyploidization affects gene expression in living cells: pathological genome duplications often happen in cancer cells. The mechanisms and consequences of polyploidization are being studied extensively. However, quantitative determination of the polyploidization rate is challenging due to its low frequency and the absence of selective genetic markers that would phenotypically distinguish between haploids and polyploids. Our work describes a robust and straightforward method for discriminating haploid and polyploid states in the yeast Saccharomyces cerevisiae, a model organism for studying different aspects of polyploidization. The measu...
Ecological genetics
Background. The alpha-test allows to detect inherited genetic changes of different types, as well... more Background. The alpha-test allows to detect inherited genetic changes of different types, as well as phenotypic expression of primary DNA lesions before the lesions are fixed by repair. Here we investigate ability of the alpha-test to detect base modifications induced by 6-N-hydroxylaminopurine (HAP) and determine frequency of inherited and non-inherited genetic changes in yeast strains treated with HAP. Materials and methods. The alpha-test is based on mating type regulation and detects cell type switch from to a in heterothallic yeast Saccharomyces cerevisiae. The frequency of mating type switching reflects level of both spontaneous and induced by a mutagen DNA instability. The alpha-test may be performed in two variants: illegitimate hybridization and cytoduction. Conducting both complementary tests and analysis of phenotypes of the illegitimate hybrids and cytoductants allows to detect the full spectrum of genetic events that lead to mating type switching, such as chromosome III...
Journal of Heredity
The Puma lineage within the family Felidae consists of 3 species that last shared a common ancest... more The Puma lineage within the family Felidae consists of 3 species that last shared a common ancestor around 4.9 million years ago. Whole-genome sequences of 2 species from the lineage were previously reported: the cheetah (Acinonyx jubatus) and the mountain lion (Puma concolor). The present report describes a whole-genome assembly of the remaining species, the jaguarundi (Puma yagouaroundi). We sequenced the genome of a male jaguarundi with 10X Genomics linked reads and assembled the whole-genome sequence. The assembled genome contains a series of scaffolds that reach the length of chromosome arms and is similar in scaffold contiguity to the genome assemblies of cheetah and puma, with a contig N50 = 100.2 kbp and a scaffold N50 = 49.27 Mbp. We assessed the assembled sequence of the jaguarundi genome using BUSCO, aligned reads of the sequenced individual and another published female jaguarundi to the assembled genome, annotated protein-coding genes, repeats, genomic variants and their...
Cancers, 2021
The authors wish to make the following corrections to this paper [...]
Supplemental materials include 11 Suppl figures - pdf-files,6 Suppl Tables, 4 pdf and 2 excel fil... more Supplemental materials include 11 Suppl figures - pdf-files,6 Suppl Tables, 4 pdf and 2 excel files Suppl Results, 2 pdf files.Supplemental Results 1. Problems with the construction of haploid yeast strains with DNA polymerase alleles reducing fitness.<i></i>Supplemental Results 2. Estimation of the probabilities of recurrent mutations in the same gene. Supplemental Table 1. Mutator effect of <i>pol2rc-</i><i>Δ</i><i>N</i> is reduced 60% in strain without the catalytic subunit of pol ζ, Rev3.Supplemental Table 2. Differences in mutant frequencies with or without UV-light irradiation in <i>pol2rc-</i><i>Δ</i><i>N</i> <i>vs</i>. wild-type strains.Supplemental Table 3. The <i>pol2rc-</i><i>Δ</i><i>N </i>elevated chromosome instability.Supplemental Table 4. (Excel file) Summary of mutations found in the course of genomic sequencing of the <i>pol2rc-ΔN...
Yeast, 2013
The alpha-test : defining the nature of mating type switching alpha -> a in heterotallic yeast... more The alpha-test : defining the nature of mating type switching alpha -> a in heterotallic yeast S. cerevisiae
Cancers, 2021
Multiple myeloma (MM) is a malignant neoplasm of terminally differentiated immunoglobulin-produci... more Multiple myeloma (MM) is a malignant neoplasm of terminally differentiated immunoglobulin-producing B lymphocytes called plasma cells. MM is the second most common hematologic malignancy, and it poses a heavy economic and social burden because it remains incurable and confers a profound disability to patients. Despite current progress in MM treatment, the disease invariably recurs, even after the transplantation of autologous hematopoietic stem cells (ASCT). Biological processes leading to a pathological myeloma clone and the mechanisms of further evolution of the disease are far from complete understanding. Genetically, MM is a complex disease that demonstrates a high level of heterogeneity. Myeloma genomes carry numerous genetic changes, including structural genome variations and chromosomal gains and losses, and these changes occur in combinations with point mutations affecting various cellular pathways, including genome maintenance. MM genome instability in its extreme is manife...
Genetics, 2021
Current eukaryotic replication models postulate that leading and lagging DNA strands are replicat... more Current eukaryotic replication models postulate that leading and lagging DNA strands are replicated predominantly by dedicated DNA polymerases. The catalytic subunit of the leading strand DNA polymerase ε, Pol2, consists of two halves made of two different ancestral B-family DNA polymerases. Counterintuitively, the catalytically active N-terminal half is dispensable, while the inactive C-terminal part is required for viability. Despite extensive studies of yeast Saccharomyces cerevisiae strains lacking the active N-terminal half, it is still unclear how these strains survive and recover. We designed a robust method for constructing mutants with only the C-terminal part of Pol2. Strains without the active polymerase part show severe growth defects, sensitivity to replication inhibitors, chromosomal instability, and elevated spontaneous mutagenesis. Intriguingly, the slow-growing mutant strains rapidly accumulate fast-growing clones. Analysis of genomic DNA sequences of these clones r...
Cancers, 2020
Recent studies on tumor genomes revealed that mutations in genes of replicative DNA polymerases c... more Recent studies on tumor genomes revealed that mutations in genes of replicative DNA polymerases cause a predisposition for cancer by increasing genome instability. The past 10 years have uncovered exciting details about the structure and function of replicative DNA polymerases and the replication fork organization. The principal idea of participation of different polymerases in specific transactions at the fork proposed by Morrison and coauthors 30 years ago and later named “division of labor,” remains standing, with an amendment of the broader role of polymerase δ in the replication of both the lagging and leading DNA strands. However, cancer-associated mutations predominantly affect the catalytic subunit of polymerase ε that participates in leading strand DNA synthesis. We analyze how new findings in the DNA replication field help elucidate the polymerase variants’ effects on cancer.
Molecular Biology, 2020
Classical views of hereditary mechanisms consider linear nucleic acids, DNA and RNA, as template ... more Classical views of hereditary mechanisms consider linear nucleic acids, DNA and RNA, as template molecules wherein genetic information is encoded by the sequence of nitrogenous bases. The template principle embodied in the central dogma of molecular biology describes the allowed paths of genetic information transfer from nucleic acids to proteins. The discovery of prions revealed an additional hereditary mechanism whereby the spatial structure is transmitted from one protein molecule to another independently of the sequence of nitrogenous bases in their structural genes. The simultaneous existence of linear (type I) and conformational (type II) templates in one cell inevitably implies their interaction. The review analyzes the current data confirming the idea that protein amyloid transformation may influence the genome stability and considers potential mechanisms of interactions between type I and type II template processes. Special attention is paid to the joint contribution of the two process to tumor "evolution" and the mechanisms of genome destabilization due to amyloid transformation of proteins in Alzheimer's and Parkinson's diseases and Down syndrome.
Frontiers in Genetics, 2017
Lada et al. APOBEC Mutations in Resting Diploid Yeast APOBEC1 behaved similar to PmCDA1. We concl... more Lada et al. APOBEC Mutations in Resting Diploid Yeast APOBEC1 behaved similar to PmCDA1. We conclude that replication, transcription, and mitotic recombination contribute to the recovered APOBEC-induced mutations in resting diploids. The mechanism is relevant to the initial stages of oncogenic transformation in terminally differentiated cells, when recombination may lead to the LOH exposing recessive mutations induced by APOBECs in cell's history and to acquisition of new mutations near original break.
Russian Journal of Genetics: Applied Research, 2017
Amyloidogenesis in nerve tissues cause human diseases such as Alzheimer's disease, Parkinson's di... more Amyloidogenesis in nerve tissues cause human diseases such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, and the illness of Louis Gehrig, characterized by specific neurodegenerative symptoms. The frequency of nerve cells with an abnormal number of chromosomes is increased in patients with Alzheimer's disease. However, the direct impact of prions on the genome stability has not been sufficiently investigated. In our work, we studied the impact of the [PSI+] prions on the stability of the S. cerevisiae genome using the alpha-test system.
Cell and Tissue Biology, 2017
⎯Synchronization of cell division in yeast cultures of Saccharomyces cerevisiae is widely used in... more ⎯Synchronization of cell division in yeast cultures of Saccharomyces cerevisiae is widely used in studies on regulation of eukaryotic gene expression and biochemical processes at different stages of the cell cycle. In this study, we compared the efficacy of modern widely used methodologies to achieve and assess the degree of synchronization of cell division in yeast. Based on the literature and our own data, we propose practical recommendations for synchronization of cell divisions in S. cerevisiae using chemical reagents (alpha-factor, hydroxyurea, nocodazole), and a genetic cell-cycle block (temperature-sensitive mutation cdc28-4).
Ecological genetics, 2015
Background. A lot of neurodegenerative diseases are coursed by amiloidization of proteins in nerv... more Background. A lot of neurodegenerative diseases are coursed by amiloidization of proteins in nerve tissues. In the patients brains suffered from Alzheimer’s disease the high fraction of the nerve cells with abnormal chromosome amount was revealed. There are some data showing that prion form of protein PrP may prevent chromosome segregation in mitosis. But the direct association of prionisation and genome stability was not revealed. Materials and methods. We compared the yeast S. cerevisiae strain bearing the prion form of the termination translation factor Sup35, and the strain with non-prionized Sup35 in the alpha-test system. The model of the alpha-test is based on the mechanism of mating type switching in heterothallic yeast strains. The MAT locus that controls the mating type of yeast cell can be presented by two idiomorphs: the MATalpha and MATa that determine the alpha and a cell types, correspondingly. Only two cells with opposite mating types (alpha × a) could copulate. In t...
Gigiena i sanitariia
Primary (spontaneous and externally induces) damages to genetic material frequently lead to herit... more Primary (spontaneous and externally induces) damages to genetic material frequently lead to heritable changes (gene mutations, chromosome aberrations and nondisjunction), which may cause cancer inherent and inborn diseases. It is suggested that primary damages may affect a phenotype until they are repaired or become mutations during inaccurate repair The alpha-test on the yeast Saccharomyces cerevisiae can answer the fundamental questions as the nature of primary damages that can be phenotypically manifested, their occurrence, conversion to each other and repair or conversion to heritable changes in genetic material.
Russian Journal of Genetics, 2011
The hypothesis on a relationship between the high frequency of mitotic disturbances in bone marro... more The hypothesis on a relationship between the high frequency of mitotic disturbances in bone marrow cells and the change in the activity of the S9 liver fraction containing promutagen-activating enzymes under olfactory stress in the house mouse Mus musculus has been tested. For this purpose, the effect of the pheromone 2,5-dimethylpyrazine on the frequency of mitotic disturbances in mouse bone marrow cells has been measured by the anaphase-telophase assay. The Ames test using Salmonella typhimurium has been employed to compare the capacities of the S9 liver fractions from stressed and intact mice for activating the promutagen 2-aminofluorene. It has been demonstrated that the increased frequency of mitotic disturbances in bone marrow cells induced by the pheromonal stressor in male house mice is accompanied by an increased promutagen-activating capacity of the S9 liver fraction. The model system used in the study allowed the genetic consequences of the exposure to the olfactory stressor to be estimated and the possible mechanisms of genome destabilization to be assumed.
Journal of Mathematical Sciences, 2006
In approximation theory, a number of quantities are interrelated via orthogonal transformations. ... more In approximation theory, a number of quantities are interrelated via orthogonal transformations. The revelation of these orthogonalities allows one to obtain useful relations and, in particular, to use known theorems on the Fourier coefficients. The paper considers this approach in application to the Fourier transforms of finite functions, to the best L2-approximations, and to trigonometric polynomials with coefficients in a vector space. Bibliography: 11 titles.
Journal of Mathematical Sciences, 2008
V n,2l (t) = (2l − 1)!2 2l−1 λ 2l π(n + 1) 2l−1 sin (n+1)t 2 t 2l , λ 2l = l−1 k=0 (−1) k C k 2l ... more V n,2l (t) = (2l − 1)!2 2l−1 λ 2l π(n + 1) 2l−1 sin (n+1)t 2 t 2l , λ 2l = l−1 k=0 (−1) k C k 2l (l − k) 2l−1 , be the generalized Jackson-Vallée-Poussin integral. Denote Km(f) = Km,ϕ(f) = sup 0<v<∞ ωm(f, v) ϕ(v). The paper studies the quantity Km(f −D n,r,l (f)). The general results obtained are applicable to other approximation methods. Bibliography: 11 titles.
Journal of Mathematical Sciences, 2007
In the paper, a generalization of a known theorem by Hardy and Young is obtained; a formula inter... more In the paper, a generalization of a known theorem by Hardy and Young is obtained; a formula interrelating the integral of a 2π-periodic function over the period with the integral over the entire axis is established; new approximation characteristics for functions belonging to saturation classes of continuity modules of different orders for the spaces Lp of periodic functions are provided, and some issues concerning approximation, in the uniform metric, of continuous periodic functions even with respect to each of their variables and having nonnegative Fourier coefficients are considered. Bibliography: 17 titles.