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PubMedDate not supplied

Characterization of seven (CTT)(n) microsatellite loci in the Pyrenean endemic Borderea pyrenaica (Dioscoreaceae): remarks on ploidy level and hybrid origin assessed through allozymes and microsatellite analyses.

We present the identification and characterization of microsatellite loci in the Pyrenean endemic Borderea pyrenaica Miégeville (Dioscoreaceae). Seven microsatellite loci were isolated from a (CTT)(n)-enriched partial genomic library. Electropherograms patterns suggest that B. pyrenaica is a tetraploid species, as is its congener B. chouardii. One microsatellite locus was monomorphic, whereas the remaining ones presented from 2 to 10 alleles when analyzed in a sample of 60 individuals. Microsatellites have revealed higher levels of genetic variability than those in previous studies based on allozymes. Levels of genetic diversity are discussed in terms of tetrasomic (autotetraploidy) or duplicated disomic (allotetraploidy) modes of allele segregation. According to the first hypothesis, mean levels of genetic variability (H(min)-H(max)) range between 0.36 and 0.41, whereas, according to the second hypothesis, the 7 primer pairs amplified 11 chromosomal loci, and mean levels of observed and expected heterozygosities were 0.217 and 0.229, respectively, and did not differ significantly from HW expectations. These results suggest a hybrid allopolyploid origin for the Borderea taxa.

Base Sequence↗
PubMed1985

Ploidy levels in nonneoplastic and neoplastic thyroid cells.

DNA levels in nonneoplastic and neoplastic human thyroid cells were studied by slide-cytophotometric and flow-cytophotometric techniques. Normal epithelial thyroid cells and cells from nonneoplastic thyroid disorders, i.e., toxic goiter, colloid goiter and chronic lymphocytic thyroiditis, had euploid (diploid, polyploid) DNA levels. The same was the case for benign tumors. Malignant tumors had either euploid DNA levels, indistinguishable from those in nonneoplastic and benign neoplastic cell populations, or aneuploid DNA levels. Taking into account the histopathologic diagnosis, clinical course and DNA level, the results indicate that DNA measurements in thyroid gland lesions are of limited diagnostic help but may contribute valuable prognostic information. To obtain representative and accurate DNA measurements, combined slide-cytophotometric and flow-cytophotometric techniques should be used.

Adenoma↗
PubMed1988

DNA ploidy level and cell cycle distribution in ovarian cancer: relation to histopathological features of the tumor.

We analyzed nuclear DNA content and S-phase fraction (SPF) from 157 paraffin-embedded ovarian tumors by flow cytometry and compared the results with the clinicopathological features of the tumors. DNA aneuploidy was more common and mean SPF was higher in advanced than in early-stage tumors (p less than 0.001). DNA aneuploidy was most often (75%) observed in undifferentiated tumors (World Health Organization classification) and most seldom (30%) in mucinous carcinomas. Mean SPF values ranged from 17.7% in undifferentiated carcinomas to 11.1% in mucinous carcinomas. DNA flow cytometric results correlated better with nuclear than with histological tumor grade. The proportion of DNA-aneuploid tumors increased from 30% in nuclear grade I to 93% in nuclear grade III, and mean SPF increased from 9.9 to 20.2% (p less than 0.001). DNA ploidy and SPF were independently associated with both stage and nuclear grade of the tumor, whereas the differences between the histopathological tumor types virtually disappeared when the groups were adjusted for nuclear grade. On the basis of these clinicopathological correlations, it appears that DNA ploidy and SPF reflect the malignant potential of ovarian tumors and thus complement the routine histopathological evaluation.

Adenocarcinoma↗
PubMed1992

[Ploidy level in Streptomyces cerevisiae strain 15B-P4 strain].

Hybridization analysis of seven clones of Saccaromyces cerevisiae 15B-P4 strain, which were obtained from different cultures, was carried out. Yeast strains taken from the Peterhoff breeding stocks were kept in the laboratory of genetics at Biological Institute of Irkutsk University from 1970. Increase in the number of prototrophic segregants was shown to by the result of aneuploidy (2n + 1) in the hybrids under study. Aneuploidy was revealed for the chromosomes I, III, IX, XII. Disomic clones of 15B-P4 strain were unstable.

Alleles↗
PubMed2005

Genomic relationships among Nicotiana species with different ploidy levels revealed by 5S rDNA spacer sequences and FISH/GISH.

We used the intergenic spacer sequences of the 5S ribosomal RNA genes (5S rDNA) to obtain insights into the genomic origin of putative amphidiploid/tetraploid species with 2n = 48 and their descendants in Nicotiana. Amplification of the spacer sequences and subsequent multiple alignment using the consensus sequences from each species, showed that two Australian species shared common large deletions, suggesting that the origin of the 5S rDNA is closely related in these species. Comparison of the spacer sequences with those from diploid (2n = 24) Nicotiana species made it possible to detect some groups consisting of the sequences from the 2n = 24 and 2n = 48 level species. Chromosomal localizations of the 5S rDNA arrays were similar in most groups. The relationships suggested by the 5S rDNA were also assessed at the genome level by using genomic in situ hybridization. We showed that the grouping based on the 5S rDNA spacer sequence reflects high genomic homology between 2n = 24 and 2n = 48 level species. As a result, the putative polyploid species such as N. debneyi, N. quadrivalvis, and N. africana were suggested to involve the close relatives of the diploid species such as N. glauca, N. obtusifolia and N. sylvestris, and N. langsdorffii, respectively, in their speciation. Our results are generally in agreement with the relationships previously suggested by morphological and cytogenetic observations, and some novel relationships were also revealed.

Base Sequence↗
PubMed1984

[Changes in the protein mass and ploidy level of the myocytes in the mouse heart].

Neonatal mice were grown until 3 weeks of age at a rate of four or sixteen per litter (groups I and II, respectively). The group I animals were characterized by accelerated growth. At day 21 of postnatal development their body and heart weights were three times greater than those of the group II animals. The mean protein content in cardiomyocytes of the group I animals increased faster, correlating with the increase of the heart weight. The fast-growing mice showed an increase in the number of polyploid cardiomyocytes (polynucleate cells mainly), amounting to 15-16% as compared with 2-4% seen in normal and slow-growing animals.

Animals↗
PubMed2004

Comparative and evolutionary analysis of the cytochrome b sequences in cyprinids with different ploidy levels derived from crosses.

The mitochondrial cyt b genes in the allotetraploid and triploid crucian carp as well as triploid common carp were isolated and completely sequenced. Their DNA sequences were compared with those derived from the cyt b genes of the red crucian carp, Japanese crucian carp, and common carp with MEGA 1.0 software. Phylogenetic analysis revealed the sister relationships between allotetraploid and diploid red crucian carp, between the triploid crucian carp and diploid Japanese crucian carp, and between triploid common carp and diploid common carp. Our results indicated the cyt b genes in the allotetraploid, triploid crucian carp, and triploid common carp were maternally inherited. Through maternal inheritance, the cyt b gene in the F11 tetraploid displayed extremely high similarity to that in the female parent red crucian carp after 11 generations (from F1 to F11 hybrids). Since the establishment of the new tetraploid stocks has great significance in analyzing evolutionary theory of vertebrate and in improving aquaculture industry, analysis of the cyt b gene and the elucidation of the variation of the cyt b gene DNA in different cyprinids prove that cyt b is a useful genetic marker to monitor the variations in the progeny of the crosses.

Amino Acid Sequence↗
PubMed1995

Relationship between DNA ploidy level and tumor sociology behavior in 12 nervous cell lines.

Cell population sociology was studied in two medulloblastomas and 10 astrocytic human tumor cell lines by means of the characterization of the structure of neoplastic cell colonies growing on histological slides. This was carried out via digital cell image analysis of Feulgen-stained nuclei, to which the Delaunay triangulation and Voronoi paving mathematical techniques were applied. Such assessments were compared to the DNA polidy level (assessed by means of DNA histogram typing). The results show that the cell colony architecture characteristics differed markedly according to whether the cell lines were euploid (diploid or tetraploid) or aneuploid (hyperdiploid, triploid, hypertriploid, or polymorphic). In fact, the cell colonies from the euploid cell nuclei populations were larger and more dense than those from the aneuploid ones. Furthermore, for an identical period of culture, the cell lines from high-grade malignant astrocytic tumors (glioblastomas) exhibited cell colonies that were larger and more dense than those in cell lines from low-grade astrocytic tumors (astrocytomas). In each of these two groups, the diploid cell nuclei populations exhibited cell colonies larger and more dense than the nondiploid colonies. The present methodology is now being applied in vivo to histological sections of surgically removed human brain tumors in order to distinguish between high-risk clinical subgroups and medium-risk subgroups in clearly circumscribed histopathological groups.

Aneuploidy↗
PubMed1993

Relationship between proliferative activity and ploidy level in a series of 530 human brain tumors, including astrocytomas, meningiomas, schwannomas, and metastases.

By identifying six DNA histogram types (diploid, hyperdiploid, triploid, hypertriploid, tetraploid, and polymorphic) in a series of 206 astrocytic tumors, we showed recently that patients with hypertriploid astrocytic tumors have a better possibility of survival than patients with other DNA histogram-type related tumors. In the present work DNA histogram type and proliferation index (S-phase fraction) are characterized in a series of 530 adult tumors from the central and peripheral nervous systems. Of these 530 tumors, there were 79 nerve sheath tumors, 181 meningiomas, 221 astrocytic tumors, and 49 metastases. Analysis was performed by means of digital cell image examination of Feulgen-stained nuclei from formalin-fixed, paraffin-embedded tumors. The data reveal that there was a majority of diploid tumors (66%) in the primary tumor group (nerve sheath tumors, meningiomas, and astrocytic tumors), while aneuploid tumors were in a marked majority (90%) in the secondary (metastatic) brain tumor group, with a predominance (47%) of the polymorphic tumor type. Independently of tumor histopathologic group, the hypertriploid-type tumors proliferated less actively than the five other types. Such a feature might partly explain the better prognosis associated with hypertriploid astrocytic tumors as compared with what occurs with respect to the other DNA histogram-type related tumors.

Astrocytoma↗
PubMed1997

Impact of taxol-mediated stabilization of microtubules on nuclear morphology, ploidy levels and cell growth in maize roots.

Direct contact of the radiating perinuclear microtubules (MTs) with the nuclear envelope was visualized with an immunogold technique using specific monoclonal tubulin antibody. The possibility that these perinuclear MT arrays are involved in establishing and maintaining nuclear organization during the interphase of cycling cells in maize root meristems was tested using taxol, a MT-stabilizing agent. Taxol not only stabilized all MTs against the action of the MT-disrupters colchicine and oryzalin but also prevented these agents from their usual induction of nuclear enlargement and decondensation of nuclear chromatin. On the contrary, nuclear size decreased and the chromatin became more compact in mitotically cycling cells of the taxol-treated root apices. Moreover, taxol prevented the stimulation, by colchicine and oryzalin, of the onset of the S phase in cells of the quiescent centre and proximal root meristem. Exposure of maize roots to taxol strongly decreased final cell volumes, suggesting that the more condensed nuclear chromatin is less efficient in genome expression and that this accounts for the restriction of cellular growth. All these findings support the hypothesis that MT arrays, radiating from the nuclear surface, are an essential part of an integrated plant 'cell body' consisting of nucleus and the MT cytoskeleton, and that they regulate, perhaps via their impact on chromatin condensation and activity, progress through the plant cell cycle.

Cell Division↗
PubMed1991

Correlation of DNA ploidy levels with altered cytokeratin patterns in rat bladder tumors.

Flow cytometry analysis of primary bladder carcinoma cells is appropriate for demonstrating the association between the presence of aneuploid cells and increased malignant potential for transitional cell carcinoma (TCC). Our laboratory previously has reported a specific alteration in the cytokeratin (CK) pattern of experimentally induced bladder carcinomas in rats. Unique immunohistochemically detectable changes in CK expression were the loss of CK 13 expression in invasive TCC cells and the loss of CK 19 expression in induced TCC. We now report the correlation of these changes in CK expression with cellular aneuploidy of the induced bladder carcinomas. Bladder carcinomas were induced in rats by direct instillation of N-methyl-N-nitrosourea. Immunohistochemistry was performed on the induced tumors using four commercially available monoclonal antibodies specific for CK 18 (TR1031), CK 13 (K8.12), CK 19 (K4.62), and the CKs 5, 7, and 8 (K8.13). Flow cytometry data from the induced bladder carcinomas was analyzed and the DNA index, proliferative index, and percent aneuploid cells were calculated for each time point. The percent aneuploid cells and CK 19 staining were tested statistically and were shown to be negatively correlated. We therefore hypothesize that the combination of the loss of CK 19 as detected by the antibody K4.62 coupled with the presence of aneuploid cells in histopathologically diagnosed invasive TCC is a significant factor in predicting the prognosis for any given diagnosis.

Animals↗
PubMed1985

Flow cytometric determination of DNA ploidy level in nuclei isolated from paraffin-embedded tissue.

Nuclei, isolated from paraffin-embedded tissue, were stained with propidium iodide (PI) and found suitable for DNA analysis by flow cytometry (FCM). DNA-derived fluorescence intensity, however, was always decreased and had a much higher intersample variability as compared to results obtained with fresh material. Using chicken red blood cells (CRBC) as a model system, we found the lower fluorescence intensity to be due to the formalin fixation step in tissue processing. The intersample variability was found to be at least partly caused by variations in the duration of fixation. Overnight trypsinization improved the fluorescence intensity but did not reduce the intersample variability. Under all conditions tested PI binding to CRBC appeared to be saturable. Since fresh diploid or red blood cells could not be used to standardize DNA histograms, an alternative approach was developed in which nuclei from paraffin-embedded normal and tumor tissue of the same specimen were mixed. With this method DNA indices (DI) of 24 colorectal cancers were found to be closely correlated (r = 0.9877, P less than 0.001) with DI obtained with fresh tumor tissue from the same patients. The correlation of the percentages of S-phase nuclei between paraffin-extracted and fresh samples (r = 0.5875, P less than 0.05) was as high as could be expected, taking sampling differences into account. This method is an important tool for the retrospective analysis of FCM-derived DNA parameters in relation to diagnosis and prognosis of neoplasms.

Animals↗
PubMed1975

Ploidy level and mutation to hypoxanthine-guanine-phosphoribosyl-transferase (HGPRT) deficiency in Chinese hamster cells.

The X-ray induction of 8-azaguanine (AG) resistent mutants in two sets of diploid and tetraploid Chinese hamster cells (DON and V79) was investigated. It was found that (i) the induced mutant frequencies in diploid and tetraploid cells appeared to be of the same order of magnitude and (ii) all mutants showed almost complete loss of hypoxanthine-guanine-phosphoribosyl-transferase (HGPRT) activity except that in the tetraploid V79 cells 50--100% of activity was retained. The gene--dosage effect for glucose-6-phosphate dehydrogenase (G6PD) in these cells make it possible to determine the number of chromosomes bearing the HGPRT-gene in mutants by measuring the G6PD activity per cell. The results show that the spontaneous and induced mutants from the diploid V79 and DON as well as the tetraploid DON cells retained the G6PD activity of the parental cells, whereas the induced mutants from the tetraploid V79 cells had about 35% of the parental G6PD activity. With 6-thioguanine (TG) as selective agent, the induced mutant frequencies in diploid and tetraploid DON cells and in diploid V79 cells appeared to be of the same order of magnitude but no mutants could be recovered from tetraploid V79 cells in a single step. TG-resistant tetraploid V79 cells could only be obtained from the AG-resistant mutants after a second selection. The HGPRT activity was lost in these mutants and some of them showed an increase in G6PD activity. The combined data cannot be explained on the basis of a single genetic mechanism.

Alleles↗
PubMed2000

Analysis of habituated embryogenic lines in Asparagus officinalis L.: growth characteristics, hormone content and ploidy level of calli and regenerated plants.

Habituated asparagus embryogenic lines derived from eleven genotypes were maintained on hormone-free medium and grew actively through secondary embryogenesis. Secondary embryos were of single cell origin and emerged from the transversal division of some epidermal or subepidermal cotyledonary cells of primary embryos. The intensity of secondary embryogenesis was found to be variable between embryogenic lines. Plants regenerated from three of these lines have been previously demonstrated to carry a mutation whose phenotype was the direct appearance of somatic embryos on apices or nodes cultured on hormone-free medium. Habituated lines of embryogenic calli and various tissues of embryogenic mutant and wild type plants were analysed for their hormonal content in ABA, IAA, iP, Z and their metabolites ABA-GE, iPA, iMP, ZR. No significant difference was found between different embryogenic lines, except the level of iPA, or between cladophyll or apex cultures of mutant and wild type plants. Flow cytometry analyses indicated only 34% of the embryogenic lines were diploid, most of the others being tetraploid, but 62% of regenerated plants from these lines were diploid. This indicated the process of maturation and conversion selected diploid embryos in the embryogenic lines.

Journal Article↗
PubMed2002

[Instability of the ploidy level in autotetraploid sorghum plants from a line with variable male fertility].

It was found that, in some of the plants in generations C1-C5 of induced tetraploids in the semisterile sorghum line AS-1-30, more than 30% of pollen grains (PGs) have sizes typical of haploid PGs. Pollen of these plants was used to pollinate different lines of sorghum with cytoplasmic male sterility (CMS). Diploid hybrids were obtained, which confirms the presence of haploid PGs in the tetraploids studied. When tetraploid plants with an increased frequency of haploid PGs were pollinated with pollen of plants from fertile diploid lines, diploid hybrids were also obtained. This demonstrates that the tetraploids studied had haploid ovicells. In generation C4, a chimeric plant was found; one of its shoots was diploid (judging from morphological characters) and produced as many as 99% of haploid PGs. It is assumed that haploid gametes in autotetraploids are formed through somatic reduction of chromosomes at different ontogenetic stages.

Edible Grain↗