BACKGROUND: Neuroblastoma is one of the most common extracranial solid tumors in childhood. At pr... more BACKGROUND: Neuroblastoma is one of the most common extracranial solid tumors in childhood. At present, epigenetic disorders play a significant role in neoplasms development. Since epigenetic changes in the cell are quite dynamic and reversible, epigenome-modulating exogenous agents can be used in epigenetic targeted therapy for various types of tumors. Therefore, the identification of these agents is still significant. Lactoferrin is one such potential molecule from the transferrin family. Currently, the anti-tumor properties of lactoferrin have been identified, but its effect on the epigenome of cells of various tumors types, particularly on neuroblastomas, is practically unknown. AIM: To study the effect of the exogenous recombinant human apolactoferrin on the viability and epigenomic status of IMR-32 neuroblastoma cells. MATERIALS AND METHODS: We studied human IMR-32 neuroblastoma cells after 72 hours of exposure to 8 doses of recombinant human apolactoferrin: 0.1, 0.5, 1, 5, 10, 50, 100 and 500 g/ml. The level of genome-wide DNA methylation and the degree of chromatin compaction in IMR-32 cells were quantified using commercial kits 5-mC DNA ELISA Kit, Global DNA Methylation LINE-1 Kit, as well as enzymatic hydrolysis of MspI / HpaII and DNaseI. RESULTS: The recombinant apolactoferrin reduces the viability of IMR-32 and, depending on the dose, differentially affects the level of genome-wide DNA methylation (СpG dinucleotides, CCGG sites, LINE-1 repeats) and the degree of chromatin compaction. At the same time, a complex picture of the epigenomic cellular response to the effect of apo-lactoferrin was observed (nonlinear nonmonotonic dose-effect relationship). CONCLUSIONS: We assumed that apolactoferrin modulates gene activity through epigenetic mechanisms, in particular, by changing the DNA methylation pattern and affecting the chromatin structure, which may be one of the molecular mechanisms of its anti-tumor effect.
BACKGROUND: Bisphenol A is a chemical agent ubiquitous in plastic consumer products and a toxin c... more BACKGROUND: Bisphenol A is a chemical agent ubiquitous in plastic consumer products and a toxin capable of disrupting key epigenetic mechanisms in early embryogenesis. It becomes more and more clear that early development changes in epigenetic pathways caused by exposure to toxic substances are associated with various adult diseases. Therefore the need to identify new agents capable of eliminating epigenetic mechanisms failures caused by the bisphenol A toxin becomes evident. Here we suggest lactoferrin as a normalizer of toxicant-induced epigenomic changes. Currently there is no data on the role of lactoferrin as a normalizer of epigenomic disorders under the influence of toxicants. We assume that in mammalian embryogenesis lactoferrin might function as an epigenetic modulating factor. AIM: The aim of the research is to study effects of lactoferrin on the epigenetic status of postimplantation mouse embryos, exposed to bisphenol A in utero. MATERIALS AND METHODS: In this study, 3 experimental groups of mice and two control group were used. 1. Mice on the first day of pregnancy, injected with 40 mg/kg of body weight of bisphenol A; 2. Mice on the first day of pregnancy, injected with 50 mg/kg of body weight of lactoferrin; 3. Mice on the first day of pregnancy, successively injected with 50 mg/kg body weight of lactoferrin and 40 mg/kg of body weight of bisphenol A. On the 15th day of embryonic development, the level of genome-wide DNA methylation was evaluated in different body parts of the embryos by methyl-sensitive restriction and ImageJ visualization analysis. RESULTS: We demonstrated that in post-implantation mouse embryos, exposure to bisphenol A in the prenatal period caused an increased level of genome-wide DNA methylation. The most prominent effects were observed in brain and abdominal section of the embryos. Together, the present findings confirmed that lactoferrin administration at a dose of 50 mg/kg of body weight resulted in normalization of genome-wide DNA methylation levels after bisphenol A-induced epigenetic alterations. CONCLUSIONS: We assume that lactoferrin may partially neutralize the harmful effects of bisphenol A caused aberrant methylation, and thus can potentially be used as a pharmaceutical product. Factual findings of the present study may help by development of new therapeutic approaches. Nevertheless, further research of the bisphenol A, lactoferrin and lactoferrin + bisphenol A effects on reactive oxygen species and/or antioxidant enzymes is needed.
Arteriosclerosis, Thrombosis, and Vascular Biology, 2007
Angiotensin (Ang) II exerts its important physiological functions through 2 distinct receptor sub... more Angiotensin (Ang) II exerts its important physiological functions through 2 distinct receptor subtypes, type 1 (AT 1 ) and type 2 (AT 2 ) receptors. Recently, new evidence has accumulated showing the existence of several novel receptor interacting proteins and various angiotensin II receptor activation mechanisms beyond the classical actions of receptors for Ang II. These associated proteins could contribute not only to Ang II receptors’ functions, but also to influencing pathophysiological states. Receptor dimerization of Ang II receptors such as homodimer, heterodimer, and complex formation with other G protein-coupled receptors has also been focused on as a new mechanism of their activation or inactivation. Moreover, ligand-independent receptor activation systems such as mechanical stretch for the AT 1 receptor have also been revealed. These emerging concepts of regulation of Ang II receptors and a new insight into future drug discovery are discussed in this review.
Human minisatellite UPS29 localized in one of CENTB5 introns was studied in silico and using mole... more Human minisatellite UPS29 localized in one of CENTB5 introns was studied in silico and using molecular genetic analysis. For the first time there were revealed seven UPS29 alleles which contained 6-24 repeated units. Allele consisting of 17 repeats was prevailed (91,5 %). Frequency of other alleles varied from 0,29 % to 4,39 %. UPS29 heterozygosity was 12,3 %. Minisatellite UPS29 was classified as low polymorphic and non hypervariable.
Epilepsy is a neurological disease with different clinical forms and inter-individuals heterogene... more Epilepsy is a neurological disease with different clinical forms and inter-individuals heterogeneity, which may be associated with genetic and/or epigenetic polymorphisms of tandem-repeated noncoding DNA. These polymorphisms may serve as predictive biomarkers of various forms of epilepsy. ACAP3 is the protein regulating morphogenesis of neurons and neuronal migration and is an integral component of important signaling pathways. This study aimed to carry out an association analysis of the length polymorphism and DNA methylation of the UPS29 minisatellite of the ACAP3 gene in patients with epilepsy. We revealed an association of short UPS29 alleles with increased risk of development of symptomatic and cryptogenic epilepsy in women, and also with cerebrovascular pathologies, structural changes in the brain, neurological status, and the clinical pattern of seizures in both women and men. The increase of frequency of hypomethylated UPS29 alleles in men with symptomatic epilepsy, and in w...
Qualitative and quantitative analysis of DNA methylation in situ at the level of cells, chromo so... more Qualitative and quantitative analysis of DNA methylation in situ at the level of cells, chromo somes, and the chromosomal domain is extremely important in diagnosis and treatment of various patholo gies, as well in studies of aging and the effects of environmental factors. Yet, the questions remain unresolved of whether the detectable in situ methylation patterns correspond to the actual DNA methylation per se and/or reflect the accessibility of DNA to antibodies, which depends on the structural features of chromatin and chromosome condensation. Thus, this phenomenon can result in an incorrect determination of the real DNA methylation pattern. In order to eliminate this disadvantage to the extent possible, we modified the commonly used methodology of in situ detection methylcytosine by means of monoclonal antibodies. In this study, we show that the efficiency of immunofluorescent labeling for 5 methylcytosin in centromeric hetero chromatin, chromosome arms and sister chromatids is significantly affected by the conditions of pretreat ment of chromosome preparations. We used undifferentiated murine embryonic F9 cells to show that varia tions in the conditions of storage of chromosome preparations can lead to a sharp reduction of labeling inten sity and even disappearance of the fluorescence signal in centromeric heterochromatin. Using the developed method, we discovered asymmetric methylation of sister chromatids in F9 cells and in human peripheral blood lymphocytes. This phenomena can lead to asymmetric cell division and asymmetric transcriptional status in daughter cells. Thus, the modified methodology for detection of 5 methyl cytosine in situ can pro vide for a more precise assessment of methylation of chromosomes and chromosomal regions.
The review critically examines the current state of population epigenetics. Possible mechanisms o... more The review critically examines the current state of population epigenetics. Possible mechanisms of intergenerational inheritance of epigenetic and epigenomic modifications as a condition of population epigenetics reality are examined. Special attention is paid to the role of external factors, including diet and various chemical compounds as modulators of the epigenome, and the possible inheritance of epigenetic variability characteristics under the influence of such environmental factors. The role of epigenetic mechanisms in the etiology and susceptibility to complex human diseases is considered.
The aim of this work was to identify new genetic markers associated with different forms of Parki... more The aim of this work was to identify new genetic markers associated with different forms of Parkinson's disease. A frequency of occurrence of different allele variants of minisatellite UPS29 localized in intron of centaurin p5 gene (CENTB5) was evaluated for patients with this pathology. The increase of frequency of UPS29 short alleles was observed for Parkinson's disease patients. This value depended on patient sex and age of pathology debut. Statistically significant difference with control was found only for females with early (30-50 years old) and late ( 60 years old) onset of Parkinson's disease. We suppose that UPS29 might be used as new genetic markers forearly (presymptomatic) diagnostics of some forms of Parkinson's disease.
Background. Nonsteroid estrogen – bisphenol A (BPA) can have a detrimental effect on human health... more Background. Nonsteroid estrogen – bisphenol A (BPA) can have a detrimental effect on human health, and therefore poses a potential threat to humans. The critical window for the effect of BPA is the time of early development of the embryo, especially during the activation of the embryonic genome during development to the stage of blastocyst. Therefore, it is especially important to understand how DNA methylation is modified in embryos of the earliest developmental period under the influence of BPA. Materials and methods. Mice hybrids F1 (CBAXC57BL) were once administered 0, 8 mg of BPA per mouse and the level of DNA methylation was estimated by detection the fluorescence of antibodies against 5-MeC in nuclei of GD3 and GD9 embryos. In other series, the level of DNA methylation and the rate of blastocyst development were estimated following cultivation of one- and two cells embryos in the presence of BPA (50 or 100 µM) during 72-96 hours in vitro. Results. BPA exposure induced the dec...
The review describes the molecular mechanisms and biological effects of bisphenol A exposure, whi... more The review describes the molecular mechanisms and biological effects of bisphenol A exposure, which is a chemical (ecotoxicant) that destroys the endocrine system and has epigenetic toxicity.
Currently, our understanding of associations between minisatellite polymorphisms and diseases is ... more Currently, our understanding of associations between minisatellite polymorphisms and diseases is far from clear. This is in part due to great differences in human and animal minisatellite structure. Thus, here we have used plasmids which contained the reporter gene EGFP under eukaryotic promoter ROSA26, and different allelles of human minisatellite UPS29 for both transient and stable transfection of F9 cells induced to differentiate, but not terminally differentiated, to establish whether the minisatellite would be capable of affecting expression of EGFP in the episomal state and in a closer to “native” chromatin environment. Upon transient transfection, we found enhanced reporter gene expression for constructs with minisatellite alleles inserts. By contrast, in cells that were stably transfected UPS29 alleles suppressed reporter construct expression compared to controls with no inserted UPS29 allele. The most prominent effect was observed for the shortest UPS29 allele associated wi...
Biulleten' eksperimental'noĭ biologii i meditsiny, 1983
Selective silver staining was used to study optimal conditions for demonstration of nucleolus org... more Selective silver staining was used to study optimal conditions for demonstration of nucleolus organizer regions (NORs) of chromosomes in early embryogenesis of the laboratory mouse. The NORs were not observable during the first cleavage division. During the second cleavage, 1-7 NORs per metaphase were demonstrable. The time course of NORs demonstration was elucidated from the first cleavage till the 10th day of gestation.
The picture of differential staining of early mouse embryogenesis metaphasic chromosomes, from th... more The picture of differential staining of early mouse embryogenesis metaphasic chromosomes, from the first cleavage up to 10 days of gestation, after digestion by restriction endonuclease AluI was studied. It was shown that depending on the degree of digestion by endonuclease differential bandings of G+C- or C-type were observed. After the least digestion only the first cleavage chromosomes were differently stained. A slight difference in intensity of staining between paternal and maternal chromosomes of the zygote was observed. All the mouse chromosomes were identified after AluI digestion and staining after Giemsa.
Transcriptionally active NORs of chromosomes visualized by AgNO3 staining were studied in bone ma... more Transcriptionally active NORs of chromosomes visualized by AgNO3 staining were studied in bone marrow and embryos (day 10 of gestation) of CBA and C57BL mice, as well as of (CBA x C57BL)F1 hybrids. These mouse strains were shown to differ by the average number of Ag-positive NORs in marrow cells; in hybrids, the number of NORs is greater than in the parent strains. During embryogenesis, the number of chromosomes carrying silver-stained NORs increases; however, no significant differences by this parameter was detected between hybrid and C57BL embryos. The average number of silver-stained NORs was the smallest in embryos of CBA mice.
BACKGROUND: Neuroblastoma is one of the most common extracranial solid tumors in childhood. At pr... more BACKGROUND: Neuroblastoma is one of the most common extracranial solid tumors in childhood. At present, epigenetic disorders play a significant role in neoplasms development. Since epigenetic changes in the cell are quite dynamic and reversible, epigenome-modulating exogenous agents can be used in epigenetic targeted therapy for various types of tumors. Therefore, the identification of these agents is still significant. Lactoferrin is one such potential molecule from the transferrin family. Currently, the anti-tumor properties of lactoferrin have been identified, but its effect on the epigenome of cells of various tumors types, particularly on neuroblastomas, is practically unknown. AIM: To study the effect of the exogenous recombinant human apolactoferrin on the viability and epigenomic status of IMR-32 neuroblastoma cells. MATERIALS AND METHODS: We studied human IMR-32 neuroblastoma cells after 72 hours of exposure to 8 doses of recombinant human apolactoferrin: 0.1, 0.5, 1, 5, 10, 50, 100 and 500 g/ml. The level of genome-wide DNA methylation and the degree of chromatin compaction in IMR-32 cells were quantified using commercial kits 5-mC DNA ELISA Kit, Global DNA Methylation LINE-1 Kit, as well as enzymatic hydrolysis of MspI / HpaII and DNaseI. RESULTS: The recombinant apolactoferrin reduces the viability of IMR-32 and, depending on the dose, differentially affects the level of genome-wide DNA methylation (СpG dinucleotides, CCGG sites, LINE-1 repeats) and the degree of chromatin compaction. At the same time, a complex picture of the epigenomic cellular response to the effect of apo-lactoferrin was observed (nonlinear nonmonotonic dose-effect relationship). CONCLUSIONS: We assumed that apolactoferrin modulates gene activity through epigenetic mechanisms, in particular, by changing the DNA methylation pattern and affecting the chromatin structure, which may be one of the molecular mechanisms of its anti-tumor effect.
BACKGROUND: Bisphenol A is a chemical agent ubiquitous in plastic consumer products and a toxin c... more BACKGROUND: Bisphenol A is a chemical agent ubiquitous in plastic consumer products and a toxin capable of disrupting key epigenetic mechanisms in early embryogenesis. It becomes more and more clear that early development changes in epigenetic pathways caused by exposure to toxic substances are associated with various adult diseases. Therefore the need to identify new agents capable of eliminating epigenetic mechanisms failures caused by the bisphenol A toxin becomes evident. Here we suggest lactoferrin as a normalizer of toxicant-induced epigenomic changes. Currently there is no data on the role of lactoferrin as a normalizer of epigenomic disorders under the influence of toxicants. We assume that in mammalian embryogenesis lactoferrin might function as an epigenetic modulating factor. AIM: The aim of the research is to study effects of lactoferrin on the epigenetic status of postimplantation mouse embryos, exposed to bisphenol A in utero. MATERIALS AND METHODS: In this study, 3 experimental groups of mice and two control group were used. 1. Mice on the first day of pregnancy, injected with 40 mg/kg of body weight of bisphenol A; 2. Mice on the first day of pregnancy, injected with 50 mg/kg of body weight of lactoferrin; 3. Mice on the first day of pregnancy, successively injected with 50 mg/kg body weight of lactoferrin and 40 mg/kg of body weight of bisphenol A. On the 15th day of embryonic development, the level of genome-wide DNA methylation was evaluated in different body parts of the embryos by methyl-sensitive restriction and ImageJ visualization analysis. RESULTS: We demonstrated that in post-implantation mouse embryos, exposure to bisphenol A in the prenatal period caused an increased level of genome-wide DNA methylation. The most prominent effects were observed in brain and abdominal section of the embryos. Together, the present findings confirmed that lactoferrin administration at a dose of 50 mg/kg of body weight resulted in normalization of genome-wide DNA methylation levels after bisphenol A-induced epigenetic alterations. CONCLUSIONS: We assume that lactoferrin may partially neutralize the harmful effects of bisphenol A caused aberrant methylation, and thus can potentially be used as a pharmaceutical product. Factual findings of the present study may help by development of new therapeutic approaches. Nevertheless, further research of the bisphenol A, lactoferrin and lactoferrin + bisphenol A effects on reactive oxygen species and/or antioxidant enzymes is needed.
Arteriosclerosis, Thrombosis, and Vascular Biology, 2007
Angiotensin (Ang) II exerts its important physiological functions through 2 distinct receptor sub... more Angiotensin (Ang) II exerts its important physiological functions through 2 distinct receptor subtypes, type 1 (AT 1 ) and type 2 (AT 2 ) receptors. Recently, new evidence has accumulated showing the existence of several novel receptor interacting proteins and various angiotensin II receptor activation mechanisms beyond the classical actions of receptors for Ang II. These associated proteins could contribute not only to Ang II receptors’ functions, but also to influencing pathophysiological states. Receptor dimerization of Ang II receptors such as homodimer, heterodimer, and complex formation with other G protein-coupled receptors has also been focused on as a new mechanism of their activation or inactivation. Moreover, ligand-independent receptor activation systems such as mechanical stretch for the AT 1 receptor have also been revealed. These emerging concepts of regulation of Ang II receptors and a new insight into future drug discovery are discussed in this review.
Human minisatellite UPS29 localized in one of CENTB5 introns was studied in silico and using mole... more Human minisatellite UPS29 localized in one of CENTB5 introns was studied in silico and using molecular genetic analysis. For the first time there were revealed seven UPS29 alleles which contained 6-24 repeated units. Allele consisting of 17 repeats was prevailed (91,5 %). Frequency of other alleles varied from 0,29 % to 4,39 %. UPS29 heterozygosity was 12,3 %. Minisatellite UPS29 was classified as low polymorphic and non hypervariable.
Epilepsy is a neurological disease with different clinical forms and inter-individuals heterogene... more Epilepsy is a neurological disease with different clinical forms and inter-individuals heterogeneity, which may be associated with genetic and/or epigenetic polymorphisms of tandem-repeated noncoding DNA. These polymorphisms may serve as predictive biomarkers of various forms of epilepsy. ACAP3 is the protein regulating morphogenesis of neurons and neuronal migration and is an integral component of important signaling pathways. This study aimed to carry out an association analysis of the length polymorphism and DNA methylation of the UPS29 minisatellite of the ACAP3 gene in patients with epilepsy. We revealed an association of short UPS29 alleles with increased risk of development of symptomatic and cryptogenic epilepsy in women, and also with cerebrovascular pathologies, structural changes in the brain, neurological status, and the clinical pattern of seizures in both women and men. The increase of frequency of hypomethylated UPS29 alleles in men with symptomatic epilepsy, and in w...
Qualitative and quantitative analysis of DNA methylation in situ at the level of cells, chromo so... more Qualitative and quantitative analysis of DNA methylation in situ at the level of cells, chromo somes, and the chromosomal domain is extremely important in diagnosis and treatment of various patholo gies, as well in studies of aging and the effects of environmental factors. Yet, the questions remain unresolved of whether the detectable in situ methylation patterns correspond to the actual DNA methylation per se and/or reflect the accessibility of DNA to antibodies, which depends on the structural features of chromatin and chromosome condensation. Thus, this phenomenon can result in an incorrect determination of the real DNA methylation pattern. In order to eliminate this disadvantage to the extent possible, we modified the commonly used methodology of in situ detection methylcytosine by means of monoclonal antibodies. In this study, we show that the efficiency of immunofluorescent labeling for 5 methylcytosin in centromeric hetero chromatin, chromosome arms and sister chromatids is significantly affected by the conditions of pretreat ment of chromosome preparations. We used undifferentiated murine embryonic F9 cells to show that varia tions in the conditions of storage of chromosome preparations can lead to a sharp reduction of labeling inten sity and even disappearance of the fluorescence signal in centromeric heterochromatin. Using the developed method, we discovered asymmetric methylation of sister chromatids in F9 cells and in human peripheral blood lymphocytes. This phenomena can lead to asymmetric cell division and asymmetric transcriptional status in daughter cells. Thus, the modified methodology for detection of 5 methyl cytosine in situ can pro vide for a more precise assessment of methylation of chromosomes and chromosomal regions.
The review critically examines the current state of population epigenetics. Possible mechanisms o... more The review critically examines the current state of population epigenetics. Possible mechanisms of intergenerational inheritance of epigenetic and epigenomic modifications as a condition of population epigenetics reality are examined. Special attention is paid to the role of external factors, including diet and various chemical compounds as modulators of the epigenome, and the possible inheritance of epigenetic variability characteristics under the influence of such environmental factors. The role of epigenetic mechanisms in the etiology and susceptibility to complex human diseases is considered.
The aim of this work was to identify new genetic markers associated with different forms of Parki... more The aim of this work was to identify new genetic markers associated with different forms of Parkinson's disease. A frequency of occurrence of different allele variants of minisatellite UPS29 localized in intron of centaurin p5 gene (CENTB5) was evaluated for patients with this pathology. The increase of frequency of UPS29 short alleles was observed for Parkinson's disease patients. This value depended on patient sex and age of pathology debut. Statistically significant difference with control was found only for females with early (30-50 years old) and late ( 60 years old) onset of Parkinson's disease. We suppose that UPS29 might be used as new genetic markers forearly (presymptomatic) diagnostics of some forms of Parkinson's disease.
Background. Nonsteroid estrogen – bisphenol A (BPA) can have a detrimental effect on human health... more Background. Nonsteroid estrogen – bisphenol A (BPA) can have a detrimental effect on human health, and therefore poses a potential threat to humans. The critical window for the effect of BPA is the time of early development of the embryo, especially during the activation of the embryonic genome during development to the stage of blastocyst. Therefore, it is especially important to understand how DNA methylation is modified in embryos of the earliest developmental period under the influence of BPA. Materials and methods. Mice hybrids F1 (CBAXC57BL) were once administered 0, 8 mg of BPA per mouse and the level of DNA methylation was estimated by detection the fluorescence of antibodies against 5-MeC in nuclei of GD3 and GD9 embryos. In other series, the level of DNA methylation and the rate of blastocyst development were estimated following cultivation of one- and two cells embryos in the presence of BPA (50 or 100 µM) during 72-96 hours in vitro. Results. BPA exposure induced the dec...
The review describes the molecular mechanisms and biological effects of bisphenol A exposure, whi... more The review describes the molecular mechanisms and biological effects of bisphenol A exposure, which is a chemical (ecotoxicant) that destroys the endocrine system and has epigenetic toxicity.
Currently, our understanding of associations between minisatellite polymorphisms and diseases is ... more Currently, our understanding of associations between minisatellite polymorphisms and diseases is far from clear. This is in part due to great differences in human and animal minisatellite structure. Thus, here we have used plasmids which contained the reporter gene EGFP under eukaryotic promoter ROSA26, and different allelles of human minisatellite UPS29 for both transient and stable transfection of F9 cells induced to differentiate, but not terminally differentiated, to establish whether the minisatellite would be capable of affecting expression of EGFP in the episomal state and in a closer to “native” chromatin environment. Upon transient transfection, we found enhanced reporter gene expression for constructs with minisatellite alleles inserts. By contrast, in cells that were stably transfected UPS29 alleles suppressed reporter construct expression compared to controls with no inserted UPS29 allele. The most prominent effect was observed for the shortest UPS29 allele associated wi...
Biulleten' eksperimental'noĭ biologii i meditsiny, 1983
Selective silver staining was used to study optimal conditions for demonstration of nucleolus org... more Selective silver staining was used to study optimal conditions for demonstration of nucleolus organizer regions (NORs) of chromosomes in early embryogenesis of the laboratory mouse. The NORs were not observable during the first cleavage division. During the second cleavage, 1-7 NORs per metaphase were demonstrable. The time course of NORs demonstration was elucidated from the first cleavage till the 10th day of gestation.
The picture of differential staining of early mouse embryogenesis metaphasic chromosomes, from th... more The picture of differential staining of early mouse embryogenesis metaphasic chromosomes, from the first cleavage up to 10 days of gestation, after digestion by restriction endonuclease AluI was studied. It was shown that depending on the degree of digestion by endonuclease differential bandings of G+C- or C-type were observed. After the least digestion only the first cleavage chromosomes were differently stained. A slight difference in intensity of staining between paternal and maternal chromosomes of the zygote was observed. All the mouse chromosomes were identified after AluI digestion and staining after Giemsa.
Transcriptionally active NORs of chromosomes visualized by AgNO3 staining were studied in bone ma... more Transcriptionally active NORs of chromosomes visualized by AgNO3 staining were studied in bone marrow and embryos (day 10 of gestation) of CBA and C57BL mice, as well as of (CBA x C57BL)F1 hybrids. These mouse strains were shown to differ by the average number of Ag-positive NORs in marrow cells; in hybrids, the number of NORs is greater than in the parent strains. During embryogenesis, the number of chromosomes carrying silver-stained NORs increases; however, no significant differences by this parameter was detected between hybrid and C57BL embryos. The average number of silver-stained NORs was the smallest in embryos of CBA mice.
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Papers by Eugene Patkin