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PubMed2002

[Morphological changes in smooth myocytes of cerebral arteries in experimental hypertension and after its elimination].

Using cytological, histochemical and morphometric methods, the changes of leiomyocytes of cerebral arteries was studied in 55 pups with experimental hypertension induced by coarctation of the aorta and in 15 animals following reversal of coarctation as compared to the normal characteristics of these cells established in 15 control dogs. It was established that hypertension induced hypertrophy and polyploidy of leimoyocytes of the circular muscular layer in the tunica media of the cerebral arteries, that was manifested as the increase in their nuclear DNA content and in the numbers of binuclear cells. After the elimination of hypertension, which was previously established in the cerebral vasculature, the tendency for the reversal of the changes in nuclear and cytoplasmic linear parameters of the cells examined was observed. However, the nuclear DNA content and the number of polyploid leiomyocytes in the cerebral arteries remained practically unchanged. The latter indicates that the polyploidy of leiomyocytes in the cerebral arteries is irreversible.

Animals↗
PubMed2005

Association of ploidy and sexual system in Lycium californicum (Solanaceae).

In North American Lycium (Solanaceae), the evolution of gender dimorphism has been proposed as a means of restoring outcrossing after polyploidization causes the loss of self-incompatibility. Previous studies of this process in Lycium focused on comparisons between species that differ in ploidy. We examined intraspecific variation in floral morphology and DNA content in populations of L. californicum to determine correlations between sexual system and cytotype. We also used nuclear ITS and GBSSI sequence data to determine whether diploid and polyploid forms represent the same phylogenetic species, and the phylogeographic relationships among populations and ploidy levels. Within populations, no variation in ploidy was found, although among populations there was a perfect correspondence between sexual system and cytotype. Diploid populations were all hermaphroditic, whereas tetraploid populations were all gender dimorphic. There was no clear geographic pattern to the occurrence of diploid and tetraploid forms. Phylogenetic analysis confirms that L. californicum, regardless of ploidy, forms a monophyletic group within the genus Lycium. Sequences from diploid and polyploid individuals did not form reciprocally monophyletic clades, indicating either multiple gains of polyploidy, ongoing gene flow between cytotypes, or lack of lineage sorting since the evolution of polyploidy. The correspondence between ploidy and sex expression is consistent with the hypothesis that polyploidization triggers the evolution of gender dimorphism in this and other Lycium species.

Arizona↗
PubMed1991

Aphidicolin, an inhibitor of DNA replication, blocks the TPA-induced differentiation of a human megakaryoblastic cell line, MEG-O1.

The commitment process of a human megakaryoblastic cell line (MEG-O1) induced with phorbol ester, TPA, was investigated with special reference to glycoprotein (GP) IIb/IIIa expression, multinuclear formation, and DNA replication. TPA (10(-7) mol/L) completely inhibited cellular division in MEG-O1, but did not suppress de novo DNA synthesis. Two days' culture with 10(-7) mol/L TPA was sufficient for MEG-O1 cells to initiate an irreversible commitment process. These cells could not resume cell growth and expressed GP IIb/IIIa antigen; some of them showed multinuclear form and DNA polyploidy even after removal of TPA from the culture medium. DNA histogram analysis showed that, upon treatment with TPA, the percentage of cells whose DNA ploidy was more than 8N was 5 to 10 times higher than that of control cells. Precise analysis using cell size fractionation by centrifugal elutriation method showed that there was strong correlation between the percentage of multinuclear cells and DNA polyploidy in TPA-treated cells. The percentage and staining intensity of GP IIb/IIIa and other megakaryocytic phenotypes such as von Willebrand factor and PAS staining were highest in large multinuclear cell populations, suggesting that these cells are the most differentiated population in this system. In TPA-treated cells, the activity of DNA polymerase alpha, a marker for cell growth, remained at the same level as in control cells. Aphidicolin, a specific inhibitor of DNA polymerase alpha, completely inhibited the differentiation induction of MEG-O1 cells with TPA measured by either GP IIb/IIIa expression or multinuclear cell formation. Therefore, DNA replication appears to be involved in the process of phenotypic expression as well as endomitosis in megakaryocyte differentiation of MEG-O1 cells. Aphidicolin was also effective in inhibiting megakaryocytic differentiation of other leukemia cell lines such as human erythroleukemia (HEL) and K562 cell lines induced with TPA, suggesting the close interplay of DNA replication and phenotypic expression in megakaryopoiesis.

Aphidicolin↗
PubMed1990

[A cytophotometric comparison of the age-related changes in the DNA and protein content in human atrial cardiomyocytes in heart diseases].

A study was performed on the human auricle muscle cells which were isolated from biopsies obtained in clinics during operation on heart. The nuclear DNA and the total protein in the cytoplasm were revealed by means of the two consecutive tests: the Feulgen and naphthol yellow S staining. DNA and protein contents were determined by two wave-length scanning cytophotometry. It is ascertained that under mitral defects the investigated parameters exhibit a tendency to increase with age: the nuclear ploidy and total protein content in the cytoplasm rise simultaneously with the increase in nuclear and cellular volumes, the polyploidy reaching higher levels than in myocardium of people of the same age without heart disease. If a patient suffered from ischemia, the nuclear polyploidy increased more slowly than cell hypertrophy to reach the level near the natural age limits.

Adolescent↗
PubMed1990

[A cytogenetic study of the human chorion for the purpose of the prenatal diagnosis of hereditary diseases].

Cytogenetical investigation of 50 diagnostic chorionic villus samples from women with a high risk of giving birth to babies with chromosomal and genic pathology, and of 128 chorionic samples obtained from medical abortions, both on the 8-12th weeks of gestation was performed by means of original direct chromosomal analysis. Chromosomal anomalies were found in 6 cases of diagnostic chorion biopsies (12%) and in 4 cases (3%) of medical abortions. The former group included 5 embryos with autosomal trisomy (4--Ts21 and 1--Ts13) and one embryo with monosomy 18. The latter group contained 2 embryos with X-chromosome monosomy and 2 other with chromosomal mosaicism. A significant prevalence of the female sex was found in the diagnostic group (sex ratio 0.56), but not in the medical abortion one (sex ratio 1.0). Analysis of routine chromosomal preparations and those after in situ hybridization with X-chromosome alfoid-probe YAP 1-10 revealed polyploidy in average in 0.8-1% chorion cells. The feasible causes of sex ratio distortion in embryos of diagnostic group and factors responsible for the rate of polyploidy are discussed. High reliability of originally elaborated direct "shaking-blotting" method of chromosomal preparations from chorionic villus samples is stressed.

Abortion, Induced↗
PubMed1989

Diagnosis of prospective malignancy in koilocytic dysplasias of the cervix with DNA cytometry.

DNA cytometric measurements were performed with a TV image analysis system on 90 routine cytologic cervical smears from 18 women after automatic restaining of the smears with the Feulgen method. In the cytologic follow-up all the patients revealed borderline lesions (mild to moderate dysplasia) of the epithelium with koilocytosis. Since DNA aneuploidy is widely accepted as a marker for malignancy, an attempt was made to obtain a DNA diagnosis of prospective malignancy in these cases on the basis of the detection of single aneuploid cells. Because koilocytosis strongly suggests human papillomavirus infection, euploid polyploidy might result in up to 8c (c = haploid amount of DNA). Therefore, the aneuploidy detection threshold was set to 9c, excluding values around 16c and 32c (+/- 12.5%) to avoid false-positive diagnoses in cases of higher polyploidy values. The DNA diagnosis of malignancy was made in 13 patients. In 12 of them, carcinoma in situ was diagnosed in the histologic follow-up, resulting in 100% sensitivity of the DNA diagnosis. In five patients no cells greater than 9c were measured, leading to a benign DNA diagnosis. In the histologic follow-up, six patients revealed normal epithelium or moderate dysplasia. Thus, the specificity of the DNA diagnosis was 83.3%.

Adult↗
PubMed1983

[Dry weight of isolated normal human hepatocytes and in chronic hepatitis].

Dry weight of hepatocytes of 44 patients both normal and suffering from chronic hepatitis was measured interferometrically. The hepatocyte dry weight of the normal liver was about 431 pg. With the progression of the disease, this weight increased up to 640 pg. The dry weight concentration in this case did not change. The dry weight of hepatocytes increases proportionally to the polyploidy degree both in the norm and at chronic hepatitis. It was shown that cell hypertrophy not associated with cell proliferation and polyploidy is of great importance for the reparative liver growth. In patients with strong liver disease, it was increased by 30% in comparison with the normal condition.

Adolescent↗
PubMed1995

[Detection of numerical chromosomal aberrations by FISH in "DNA-diploid" head and neck squamous cell carcinomas].

We applied Fluorescence In Situ Hybridization to DNA-diploid head and neck squamous cell carcinomas to detect numerical chromosomal aberrations. Using centromeric repetitive probes of chromosomes 1, 7, 11, 17, X, and Y, we detected numerical aberrations of chromosomes in 4 of the 7 tumors examined, the main line of one tumor showed trisomy 1, while the other 3 tumors had subpopulations that showed trisomy or monosomy of 1 or 2 chromosomes examined. We found polyploidy by cytofluorometry in all 4 tumors with numerical chromosomal aberrations. These results suggest that from DNA-diploid tumors with polyploidy, subpopulation that are aneuploid at the chromosome level may arise before the ploidy of the main line shifts to over DNA-aneuploidy.

Carcinoma, Squamous Cell↗
PubMed1994

Induction of mitotic- and meiotic-chromosome anomalies in mice and onion by distillery effluents.

A 2% dilution of distillery effluent not only inhibited mitosis but also induced a 10-fold increase in the frequency of chromosome abnormalities in onion root-tip cells. Polyploidy and disturbances in cytokinesis were also observed. A 1% dilution of the effluent, when administered orally at 0.5 ml per day per mouse, induced a 12-fold increase in chromosome abnormalities among bone marrow cells. The latter included both gross and individual types of damage. In the primary spermatocytes, the effluent induced a 14-fold increase in abnormalities among which X-Y univalents, polyploidy and translocation were most common.

Allium↗
PubMed1994

Changes in nuclear size of cardiac myocytes during the development and progression of hypertrophy in rats.

It is generally believed that nuclear enlargement indicates polyploidy. The purpose of this study was to establish whether nuclear enlargement is also a marker for cellular hypertrophy. Using isolated myocytes, we examined the growth of cardiac myocyte nuclei during cellular hypertrophy in rats with aortocaval fistulas or left ventricular myocardial infarction. A Coulter Channelyzer was used to measure the volume of the myocytes. Isolated myocytes were stained with the DNA-specific fluorochrome 4'-6-di-amidino-2 phenylindole-HCl for measurements of nuclear length and width, and calculation of nuclear volume. One week, 1 month and 5 months after aortocaval fistula surgery, the nuclear volume of right ventricular myocytes increased by 24, 55 and 56% respectively. Increased length, rather than width, accounted for most of the nuclear growth. Nuclear hypertrophy was associated with a progressive increase in cell volume at each time point (34, 88 and 118%). Adaptive growth of left ventricular myocytes followed the same trend, though the extent of cellular and nuclear hypertrophy was reduced. One month after producing a myocardial infarction, there was an increase in nuclear volume (18%) and nuclear length (11%) in right ventricular myocytes, but no changes in the surviving left ventricular myocytes. The cell volume increased in both right and left ventricles (72 and 18%, respectively). Thus, nuclear size increased as myocytes enlarged, though at a slower rate. Since nuclear DNA content does not increase in rats with aortocaval fistulas or myocardial infarction, the increase in nuclear volume was associated with cellular enlargement rather than increased polyploidy.

Animals↗
PubMedDate not supplied

[The forms of variability in a cell population as well as in an organism population. The biology of the development of the cardiac myocytes].

Variability of cells is analyzed using data obtained in studies on polyploidy in the heart muscle and on ontogenetic changes in the number of myocytes. In normal myocardium, variation in the number and ploidy of muscle cells is observed. The types of genomic variation are similar to those found in populations of organisms, i. e., to hereditary and modifying variation. In studies on modifications of the myocyte genome, heart growth reserves were revealed, which manifest themselves in pathological states associated with myocardial hypertrophy. These reserves depend on the level of myocardial polyploidy that is determined during early postnatal development.

Animals↗
PubMedDate not supplied

[Nuclear ploidy in atrial cardiomyocytes in patients with heart disease].

The content of DNA and proteins has been studied morphometrically in intraoperative biopsies of patients of different ages with congenital heart diseases and rheumatic mitral stenosis. Hemodynamic hyperfunction provoked premature polyploidy of cardiomyocytes nuclei in children with congenital vitium cordis. In cardiomyocytes of 20-50-year-old patients with acquired vitium cordis polyploidy with an increasing age does not occur, but a decline in protein synthesis and intracellular edema are observed.

Age Distribution↗
PubMedDate not supplied

Coexisting clones in diploid and near-diploid cell lines.

The karyotypic characteristics and clonal composition of human normal diploid MRC-5 (46,XY) and tumorigenic SK-UT-1 (45,XX,-13) and SK-UT-IB (46,XX) cell lines were studied. In MRC-5, 45, XX, -6; 45,X; 46, XY, t(7;14) (p11:q24) and 47, XY, M1 clones were identified. Other karyotypic characteristics included 2.4% polyploidy, 4.8% breaks/gaps, 4.1% structural anomalies, 1.4% hyperdiploidy, and 5.4% hypodiploidy. In SK-UT-1, 45, XX, -13, and clones with t(18;22) (q22.2;q11.23) and 46, XX, 4p+ occurred at 56.6%, 39.3%, and 4.1%, respectively. The t(18;22) karyotypes differed by either paired N13, one N13 plus one i(13q), or one i(13q). The significance of single chromosome amplification relating to the outgrowth in one culture by the t(18;22) clone is discussed. Structural aberrations occurred at high frequencies in N3, N6, and N7, and breaks from these chromosomes were clustered at 3p12, 3q21, 6q21, 6q23, and 7q11.2. The highly malignant SK-UT-IB had the stable karyotype and one 46X, f clone only. Clearly, the cell population was basically mosaic, containing more than one co-existing clone plus the polyploidy of each clone.

Cell Line↗
PubMed1997

Medico-genetic and cytogenetic study of a family with high predisposition to malignant disease in gastro-intestinal tract.

In a family consisting of 48 persons with high predisposition to familial stomach cancer (SCr), SCr was diagnosed in 8 persons (I-2; II-1,3,4; III-1,2,3,4). Moreover, one woman (III-8) had bilateral breast cancer and two (proband: IV-1 and her father's cousin: III-10) chronic gastritis. The proband, her father's cousin, his sister (III-11) and the proband's sister (IV-2) were examined clinically and cytogenetically (with the metaphase method on blood lymphocytes with G-banding of chromosome 21: (p12-pter) in 100% of cells on the basis of chromosomal instability; besides, the complex translocation in chromosome 2 in 4% of cells and the increase of q-arm of chromosome 21 was found in 2% of cells. The proband's sister (IV-2) had 3% of cells with polyploidy, the del 1 (p34-pter) in 1% of cells and the del 7 (p21-pter) in 4% of cells. The cytogenetic examination of the proband's uncle (III-10), carried out 3 times, revealed the case of the proband, endomitosis in 2% of cells, polyploidy in 2% of cells and hyperaneuploidy in 4% of cells. His sister (III-11) had 4% of cells with endomitosis, 3% of cells with chromosome and chromatid breaches, an increase of the p-arm of chromosome 21 in 100% of cells and the loss of 7p in 2% of cells. The nature of the phenomenon in chromosome 21 and the translocations in the members of this family is here discussed. The cytogenetic examination is currently ongoing.

Adult↗
PubMed1976

[In vivo and in vitro cytospectrophotometric studies of DNA in the cells of human neuroectrodermal brain tumors].

A rather distinct correlation in the content and distribution of DNA with the grade of malignancy was estabilished for the following series: normal astrocytes, and oligodendrocytes, typical astrocyfomas and oligodendrogliomas atypical astrocytomas and oligodendrogliomas. For glioblastomas this correlation is impaired, because the polymorphic variant of glioblastoma is characterized by particularly great disturbances in the content and distribution of DNA in the form of polyploidy and aneuploidy which, in this case, reflects not only the grade of malignancy, but also a pronounced polymorphism of tumour cells. The content of DNA in rapidly growing malignant tumours is not only an expressions of real deviation to the side of polyploidy and the mitotic cycle. In neuroectodermal tumours growing in the condition of cell culture, the similar regularity was observed, although the phenomena of aneuploidy were more distinctly expressed in the majority of tumours.

Aneuploidy↗
PubMed1998

Induction of p34cdc2 in mouse parotid glands upon activation of beta1-adrenergic receptors.

Dramatic morphological, biochemical and cytological changes occur in parotid glands of rats and mice which have been treated with the beta-adrenergic receptor agonist isoproterenol (Ipr). Changes include glandular hypertrophy, induction of tissue-specific proline-rich proteins (PRPs), increases in cAMP, and occurrence of polyploidy. Similar changes also occur after feeding mice polyphenolic compounds commonly referred to as tannins. Data are presented which show that changes in cell cycle proteins are due to stimulation of the beta-adrenergic receptor by either isoproterenol or tannin treatment of mice. Both p34cdc2 mRNA and protein levels were elevated dramatically after mice were treated. Induction of p34cdc2 occurred within 24 hrs. and was transient during treatment. The beta1-adrenergic receptor antagonist atenolol blocked both tissue-specific expression of proline-rich proteins and induction of p34cdc2. Coincident with the increase in p34cdc2, cyclin-dependent kinase complexes containing cyclins A and B increased forty- and ten-fold, respectively. These results show that in mouse parotid glands activation of the beta1-adrenergic receptor by either the administration of isoproterenol or ingestion of dietary tannins induces synthesis of p34cdc2 and most likely contributes to the occurrence of polyploidy.

Adrenergic beta-Agonists↗
PubMed2026

Diploids derived from polyploids: genetic characteristics of four novel interspecific Sorghum populations.

Polyploidy has repeatedly shaped grass evolution, yet direct observations of how polyploid-derived chromosomes behave when returned to diploidy remain rare. Interspecific crosses between diploid Sorghum bicolor and tetraploid hybrids derived from Sorghum halepense generate mixed-ploidy progeny, providing an opportunity to examine chromosome transmission during the early stages of diploidization. Using genome-wide SNP markers, we characterized chromosomal inheritance patterns in 2 diploid and 2 tetraploid families derived from these crosses. Genotype-dosage profiles alone distinguished diploids from tetraploids with complete accuracy, reflecting strong ploidy-dependent differences in dosage-class distributions. Although diploid progeny retained much of the halepense-derived genomic background, several genomic intervals exhibited extended, nonrandom runs of S. bicolor homozygosity that remained polymorphic in corresponding tetraploid populations. These patterns, together with recurrent segregation distortion across independent families, suggest that the transition from tetraploidy to diploidy can expose allelic combinations that differ in transmission or viability. Analyses of flowering time further indicated that diploid and tetraploid derivatives possess distinct genomic architectures, with major association peaks occurring in different chromosomal regions across ploidy levels. Collectively, these results indicate that early diploidization involves nonrandom retention and loss of parental haplotypes shaped by both selective and structural constraints. The diploid extractions characterized here provide a rare empirical system for investigating the early stages of diploidization and a practical framework for studying and eventually mobilizing polyploid-derived variation for sorghum germplasm development. However, broader integration into elite breeding programs will require additional evaluation of cross-fertility, meiotic behavior, and chromosomal stability across diverse breeding backgrounds.

Sorghum↗
PubMed2025

Surprisingly frequent chromosomal instability in cultivated peanut.

This study, the third in a three-part series, investigates whether chromosomal instability persists in cultivated peanut. The allotetraploid peanut (Arachis hypogaea; genome type AABB) originated from the hybridization and polyploidization of A. duranensis (AA) and A. ipaënsis (BB). Our first study established that this was an extremely narrow genetic origin, likely from a single hybridization event. This raised a paradox: how did such narrow genetics give rise to the phenotypic diversity seen in cultivated peanut? The second study addressed this, showing that a single neoallotetraploid spontaneously generates striking diversity, and that homoeologous exchanges-abundant in early generations following polyploidy-are a key mechanism in creating this diversity. In contrast to this early-generation instability, cultivated peanut is generally considered to be genetically stable, presumably due to selection. This third study tests whether residual instability still occurs in modern peanut. From a single plant of the highly selfed 'genome stock' of the cultivar 'Tifrunner', we advanced lineages through seven generations in a pollinator-free greenhouse. Among 233 plants, we identified three new large-scale chromosomal instability events: a large deletion on chromosome B01, associated with reduced pod width and seed weight, and two ABBB compositions involving chromosomes A02/B02 and A05/B05. With these observations in hand, we reinterpreted previously published data from two recombinant inbred populations. Together, these results indicate that at least 1% of pure pedigree A. hypogaea plants exhibit spontaneous large-scale chromosomal changes-a surprising frequency of instability that likely contributes to peanut's long-term adaptability and evolution.

Arachis↗