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Results for “diploidization”

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PubMed1989

[Regularities of posthyperthermic recovery in haploid and diploid yeasts Saccharomyces cerevisiae and Pichia pinus].

Isogenic diploid cells of Saccharomyces cerevisiae are more sensitive to hyperthermic treatment (50 degrees C) than haploid ones, the posthyperthermical recovery efficiency being the same for both the cell types. In contrast to this, thermosensitivity of haploid and diploid cells of Pichia pinus does not practically differ, the posthyperthermic recovery efficiency for both the cell types being also the same. It is shown that diploid cells of P. pinus in the logarithmic phase of their growth are incapable of recovering after hyperthermal treatment, which is largely the reason for their higher sensitivity to such a treatment as compared with cells in the stationary phase of growth.

Diploidy↗

PubMed1989

[Comparative study on chromosome C-banding in diploid and triploid types of Paragonimus westermani].

Diploid and triploid types of Paragonimus westermani had similar chromosomal karyotypes, however, they differed in chromosome c-band patterns. Two of three homologues of the triploid resembled those of the diploid in c-banding pattern, while the remaining chromosomes showed a different pattern. Heterogeneity in homologues was observed especially in chromosome Nos. 2, 3, 5, 6 and 7 (Fig. 1, 2). In the diploid chromosome specimen, mitotic and meiosic phases were observed, while only the mitotic phase was found in the triploid chromosome.

Animals↗

PubMed1986

Isolation of carcinogen-induced diploid rat hepatocytes by centrifugal elutriation.

The majority of hepatocytes isolated from rats treated with carcinogens (diethylnitrosamine plus 2-acetylaminofluorene) were found to be diploid, whereas most of the hepatocytes from normal rats are tetraploid. The carcinogen-induced diploid hepatocytes were only one-half the size (protein content) of the tetraploid hepatocytes, and could therefore be separated from the latter by centrifugal elutriation. The elutriation technique thus makes it possible to isolate a relatively pure fraction of carcinogen-induced cells. The diploid cells had the same liver-specific enzymatic and functional properties as the tetraploid cells and were thus undoubtedly of hepatocytic origin.

Animals↗

PubMedDate not supplied

[14C-procollagen secretion by human embryonal fibroblasts with diploid and trisomic chromosome complement].

Secretion of procollagen was studied in human embryonal fibroblasts with diploid chromosomes as well as in fibroblasts obtained from fetuses after spontaneous abortion from patients with trisomy by chromosome 7. The rate of procollagen secretion was approximately similar in these cells; the protein was shown to accumulate in intracellular matrix of diploid fibroblasts, while it did not occur in the matrix of aneuploid fibroblasts. Content of polymeric tubulin was decreased in fibroblasts with trisomy as compared with diploid cells. Impairment of the intracellular matrix structure in the cells with trisomy appears to be responsible for deterioration of morphogenesis in human chromosome anomalies.

Cells, Cultured↗

PubMedDate not supplied

[Mutagenic action of acenaphthene on haploid and diploid cultures of Candida scottii].

Acenaphthene used as vapour increases the frequency of morphological mutations as well as mutations yielding strains with a reduced activity of respiration in Candida scottii. The diploid culture has more mutants than the haploid culture. The frequency of mutants depends on the duration of acenaphthene action. Cells more resistant to the action of acenaphthene vapour are selected in the haploid culture when C. scottii cells are transferred many times into new wort drops. As a result, the frequency of mutations decreases. When the diploid culture is exposed to the action of acenaphthene vapour for a longer time, the frequency of mutations rises. Apparently, the diploid culture has a lower activity of reparation of premutational damages than the haploid culture and therefore the number of mutant cells increases.

Acenaphthenes↗

PubMedDate not supplied

[Cell morphology, nucleus distribution and DNA content in haploid and diploid Aspergillus niger strains].

The cells of haploid Aspergillus niger strains contain, on the average, 7-9 nuclei, a fragment of a thin hypha 100 me long comprising 11-19 nuclei. The cells of a diploid strain are 1.5-2.6 times larger in volume. The diploid cells contain less nuclei and more cytoplasm per nucleus as compared to the haploid strains. The primary sterigmae of Aspergillus niger comprise 3-13 nuclei, the secondary sterigmae and conidia, one nucleus. The conidia of the diploid strains are 1.8-2.0 times larger in volume and contain twice as much DNA as compared to the haploid strains.

Aspergillus niger↗

PubMedDate not supplied

[Growth characteristics of haploid and diploid Hansenula polymorpha yeasts on methanol in continuous culture].

The rate of growth and the yield of biomass of a Hunsenula polymorpha homozygous diploid strain ML-3 X ML-3 were nearly identical with those of the parent haploid culture ML-3. The two cultures were eliminated from the fermenter at D = 0.20 to 0.21 h-1. In contrast, a heterozygous diploid strain ML-3 X VKM 1397 could grow at D = 0.23 to 0.25 h-1 and its biomass yield reached 38% while the yields of the haploid and homozygous diploid strains were 35 to 36%. The pH of the medium had the same effect on the three cultures: a change in the pH from 4.0 to 3.5 and then to 3.0 did not influence the yield of biomass; a further pH drop to 2.5 made the cells be eliminated from the fermenter.

Ascomycota↗

PubMed1980

Post-exposure use of the new human diploid cell (rabies) vaccine at Clark Air Base.

Rabies is a severe problem in the Phillippines. Approximately 250 people per year die of rabies in that country. Over 200 people per year have been started on antirabies treatment at Clark Air Base, Republic of the Phillippines. A case involving three rabid dogs in one American housing area near Clark with 33 exposed individuals is presented. The use of the new human diploid cell vaccine in 31 of those people discussed. A discussion of the modalities for antirabies therapy at Clark is included. The history of the development and the clinical trials of human diploid cell vaccine is presented. Conclusions on the use of human diploid cell vaccine at United States military installations in areas endemic for rabies are offered.

Child↗

PubMed1995

[Genetic structure and origin of the tetraploid toad Bufo danatensis Pisanetz, 1978 (Amphibia, Bufonidae) of Central Asia. Differentiation of geographic forms and genetic relationship between diploid and tetraploid species].

A hierarchical system, consisting of several levels of genetic divergence, is formed by distribution of genetic distances between diploid taxa of the green toad species complex (subspecies Bufo viridis viridis--B. v. turanensis and species B. viridis--B. sp.) and taxa representing western (B. viridis s.l.) and eastern (B. raddei) Pale-arctic regions. Formally, genetic differentiation of the tetraploid toad B. danatensis from the parapatric diploid species reaches the species level. Genetic diversity of the tetraploid species is more than twofold higher than the total diversity of two modern diploid species. This suggests that B. danatensis was formed with the participation of other unknown species in the past. The polyploid species B. danatensis is assumed to have originated by hybridization of two species groups that arose approximately 2.6 million years ago in Mediterranean and Central Asian regions of the western Palearctic. The genetic heterogeneity of geographical populations of the polyploid species indicates its polyphiletic origin. The heterogeneity range suggests that formation of the tetraploid species continued for a very long period (about 1 million years).

Animals↗

PubMed1993

Development of haploid and diploid mouse parthenogenones: effect of oocyte aging in vivo.

Mouse oocytes were collected 13.5-29.5 hr after hCG injection at 4 hr intervals, then activated with 7% ethanol for 1 min. The oocytes collected 13.5 hr after hCG injection did not respond to ethanol activation. High activation rates (90.2-98.3%) were obtained in oocytes activated 17.5-29.5 hr after injection with hCG. Haploid parthenogenones were dominant though the number decreased as the age of oocytes advanced (89.5% to 42.0%). The highest number of diploid parthenogenones (20.6%) was obtained in oocytes activated 21.5 hr after hCG injection. The number of immediate cleavage and morphologically abnormal oocytes increased when the oocyte age progressed (0.7% to 34.7% and 1.1% to 23.2%, respectively). The percentage of parthenogenones developing to blastocysts decreased with the increase in oocytes age: haploid 51.9% to 1.4% and diploid 100.0% to 83.3%. The present study demonstrates that the developmental potentials of haploid and diploid parthenogenones derived from oocytes at 17.5 and 21.5 hr are higher than those derived from oocytes at 25.5 and 29.5 hr after hCG injection.

Animals↗

PubMed1995

Variation in the primary structure of waxy proteins (granule-bound starch synthase) in diploid cereals.

The molecular weights of waxy proteins, by SDS-PAGE, and the N-terminal amino acid sequences of mature protein and of V8 protease-induced fragments were determined in diploid cereals. The homology of the primary structure was relatively high among cereals examined here, and there appeared to be a common sequence, V-F-V-G-A-E-M-A, in the vicinity of the N terminus. Based on the amino acid sequences, these cereals could be divided into two groups, including corn and rice in one and diploid wheat, four Aegilops species, rye, and barley in the other. In diploid wheat and Aegilops species there were substitutions of amino acids in the primary structure. Variations of this sort suggest that the primary structure of waxy proteins would provide clues to the phylogenetic relations in the wheat group.

Amino Acid Sequence↗

PubMed1977

[Mitotic cycles in diploid strains of human fibroblast-like cells].

Determination of parameters of the mitotic cycles in 5 human diploid embryonic strains and in 4 human strains from donor skin biopsies was conducted in termal room (37 degrees C). Diploid strains of postnatal origin have a longer duration both of the whole mitotic cycle (P less than 0.001) and of particular stages G1 (P less than 0.001), G2 (P less than 0.001) (duration of S-phase was not deviated) as well as lower values for the proliferative pool during the whole cultivation to the embryonic diploid strains.

Cell Line↗

PubMed1997

[Unusual motifs of the nucleotide sequence adjacent to the putative transcription initiation site in the rDNA intergenic spacer of diploid wheat Triticum urartu Thum. ex Gandil, T. boeoticum Boiss, and T. monococcum L].

In the intergenic spacer (IGS) of rDNA of diploid wheats Triticum urartu, T. boeoticum, and T. monococcum, the uncommon motives adjacent to the site of transcription initiation (TIS) are revealed. They are located in the region from -6 to +1 relative to the putative TIS and are not encountered in cereals studied earlier. In T. urartu and T. boeoticum, the motif TACTATG has been revealed, in T. monococcum--TATTATG, while diploid Aegilops speltoides has the motif TATAGTA, typical of the remaining cereal species. The TIS-surrounding rDNA IGS region of diploid wheats was compared to the correspondent known rDNA IGS regions of different plant and animal species.

Base Sequence↗

PubMed1998

Ribonucleic acid treatment alters gene expression in diploid strains of Aspergillus nidulans.

Physical and chemical agents that promote DNA damage can induce high levels of mitotic crossing-over in eukaryotic diploid cells. Similarly, foreign DNA segments introduced by transformation processes, in the cell genome, can also induce mitotic crossing-over as an outcome of the reactions leading to chromosomic balance or due to the mechanisms aiming at the integration of the exogenous DNA. Zucchi et al. have described a system showing that RNA treatments are capable of inducing changes in the genome of haploid receptor strains of Aspergillus nidulans. To verify the genetic consequences of this process in diploid cells, conidia from two strains of this fungus were protoplastized, treated with homologous RNA and analyzed. Alterations in the gene expression and in the mitotic crossing-over frequencies between linked markers were detected. Among the main observed effects there was a generalized alteration in gene expression which was very likely caused by a reversible gene inactivation mechanism due to the methylation of cytosine residues. This was confirmed by treating the haploid segregants with the hypomethylating agent 5-azacytidine, that restored the original gene activity. The presence of a duplicated segment in the chromosome I of one of the treated diploids, interfered with the RNA general effects on its genome.

Aspergillus nidulans↗

PubMed2025

Historical introgression as a driver of diversification of diploid Picris (Compositae) in the Mediterranean Basin.

The Mediterranean Basin is recognized as one of the world's most prominent biodiversity hotspots, where past climatic changes have driven range shifts, secondary contact between populations, and gene exchange. This study investigates the impact of historical introgression on the diversification of diploid members of the genus Picris (Compositae). Using nuclear and plastid genome data obtained through the Hyb-Seq approach, we assess whether introgression contributed to the evolution of the Mediterranean Picris, potentially giving rise to multiple regional endemics. We also test whether introgression was associated with the transfer of traits such as life strategy and fruit morphology, which are involved in habitat-specific adaptation. Phylogenetic network analysis revealed two major introgression events that shaped evolutionary trajectories within the genus. The earliest and most complex events involved the Turkish endemic P. campylocarpa, which hybridized with the most recent common ancestor (MRCA) of the P. cyprica-P. pauciflora lineage and with the MRCA of the B1 subclade, comprising the P. hieracioides group and the P. scaberrima-P. strigosa lineage. The latter introgression preceded shifts from iteroparity to semelparity and from heterocarpy to homocarpy, ruling out an adaptive introgression origin for these traits. Nevertheless, all detected historical introgression events contributed to the diversification of diploid Picris taxa.

Diploidy↗

PubMed1983

Rhesus diploid rabies vaccine (adsorbed), a new rabies vaccine. II. Results of clinical studies simulating prophylactic therapy for rabies exposure.

Rhesus diploid-cell-strain rabies vaccine (RDRV) (adsorbed) is a new rabies vaccine intended for use in man. Sixty volunteers were given five doses of RDRV at 0, 3, 7, 14, and 28 days to simulate prophylactic treatment of persons exposed to a rabid animal. Thirty-five volunteers were given commercial high-titer rabies immune globulin, 20 IU/kg, before the first dose of RDRV, and 25 were given RDRV without prior rabies immune globulin. Antibody responses at 14, 28, and 42 days were comparable with those reported with human diploid rabies vaccine. Simulated postexposure prophylactic treatment with RDRV was associated with acceptable levels of local and constitutional symptoms.

Adsorption↗

PubMed1997

Diploid hydatidiform moles with fetal red blood cells in molar villi. 1--Pathology, incidence, and prognosis.

It is believed that fetal development does not occur in complete mole (CM); when present, it is usually interpreted as proof of partial mole (PM), in most cases a triploid conception with a low incidence of persistent trophoblastic disease (PTD). However, histological examination of 3180 moles in 8 years showed 60 moles (1.8 per cent) with features of CM and either embryonic tissues or amnion in the sample. Flow cytometry (FC) in 40 showed diploid complement in all. In ten of the 40, there was evidence of a twin; in 17, there was only amnion, which could belong to a twin; in the remaining 13, there was no evidence of a twin and nucleated fetal red blood cells (FRCs) were seen within molar vessels in ten (0.3 per cent). Seven of the 40 patients (17.5 per cent) and one of the ten with FRCs in villi (10 per cent) developed PTD, an incidence comparable to that of CM. Genetic studies in seven of these tea are reported separately. Finding fetal tissues with a mole or FRCs in molar vessels is not enough to classify it as PM, since it can be a CM with a twin, fetal development CM, or possibly a third type of mole. These rare diploid moles with fetal tissues have histological appearances and prognosis similar to those of CM.

Adult↗

PubMed1996

Selection toward diploid cells in prostatic carcinoma derived cell cultures.

For elucidation of the growth-regulatory mechanisms in prostatic carcinoma, in vitro investigations on prostatic cell cultures are required. However, one major problem of cell culturing is the selection of particular cell types such that the cell lines representing only some of the features as compared with the tumor of origin. We studied the chromosomal composition of 20 prostatic tissue-derived cell cultures and 12 original (fresh) tissue specimens that were obtained from 13 patients with prostatic adenocarcinoma. Using fluorescence in situ DNA hybridization (FISH), evident clonal abnormalities were detected in 78% of the fresh cancer samples and in 47% of the cultured cancer samples. Of the seven cases revealing clonal abnormalities in the fresh cancer specimen, aneuploidy was detected in only two samples after cell culturing at the earliest passage studied. The aneuploid cell populations in the cultured samples were all lost during progressive subcultivation (after passage 4). Interestingly, by performing FISH on cytogenetic preparations aneuploidy was confined to the interphases, with the metaphases being found to be diploid. This finding indicates that the aneuploid cells have a proliferation disadvantage in cell culture resulting in an overgrowth of diploid cells.

Adenocarcinoma↗