Disease relevance of Diploidy

• To investigate the potential of DNA vaccines for rabies immunization in humans, we vaccinated Macaca fascicularis (Cynomolgus) monkeys with DNA encoding the glycoprotein of the challenge virus standard rabies virus, or with a human diploid cell vaccine (HDCV) [1].
• We studied the transformation of epithelial, diploid cell lines (RL-33 and RL-34) derived from W rat liver by the Kirsten murine sarcoma virus [2].
• Non-complementing diploids (Ncd) displaying the parental phenotype can be selected from polyethylene glycol (PEG)-treated fused polyauxotrophic protoplasts of Bacillus subtilis [3].
• With aging, the partial trisomy 16 (Ts65Dn) mouse model of Down's syndrome exhibited reductions in BFCN size and number and regressive changes in the hippocampal terminal fields of these neurons with respect to diploid controls [4].
• X-ray sensitivity of diploid fibroblasts from patients with hereditary or sporadic retinoblastoma [5].

High impact information on Diploidy

• Epigenetic silencing of FLO11 regulates a key developmental switch: when FLO11 is expressed, diploid cells form pseudohyphal filaments; when FLO11 is silent, the cells grow in yeast form [6].
• These results demonstrate a role for the region 3' to Xist exon 6 in the counting process and suggest that counting is mediated by a repressive mechanism which prevents inactivation of a single X chromosome in diploid cells [7].
• The lines, mainly of erythroid or myelomonocytic origin, were diploid but highly tumorigenic from their inception [8].
• Cells retaining one wild-type p53 allele mimicked the behavior of primary diploid cells: they arrested growth in the presence of drug and failed to demonstrate amplification [9].
• They also have found a meiotic level of message in temperature-sensitive cdc25 diploids shifted to high temperature in rich medium (Simchen and Kassir, 1989) [10].

Chemical compound and disease context of Diploidy

• Comparative genomic hybridization of formalin-fixed, paraffin-embedded breast tumors reveals different patterns of chromosomal gains and losses in fibroadenomas and diploid and aneuploid carcinomas [11].
• Alkyl methane sulfonate mutation of diploid human lymphoblasts and Salmonella typhimurium [12].
• Bovine buffy coat cells infected with the bovine leukemia virus (BLV) induce syncytia formation in human diploid embryonic lung cells as well as in monolayer cell cultures of bovine, simian, ovine, bat, and caprine origin, but not in mouse fibroblast cells, normall rat kidney cells, or RSV-transformed rat cells [13].
• In a study population of 128 healthy subjects, the number of C4 genes present in a diploid genome varied between two to five, and 77.4% of the C4 genes belonged to the long form that contains the endogenous retrovirus HERV-K(C4) [14].
• H5 rat hepatoma cells were reacted with the N-nitroso carcinogen N-ethyl-N-nitrosourea in vitro, to give overall levels of greater than or equal to 25 O6-EtGua residues per diploid genome (corresponding to O6-EtGua/guanine molar ratios of greater than or equal to 10(-8) [15].

Biological context of Diploidy

• GPA1 transcript was found in haploid cells but was not detected in diploid cells [16].
• Unlike the wild-type diploid cells, the cyr1 and CYR3 homozygous diploid cells were capable of initiating meiosis even in nutrient growth media [17].
• A smaller subfragment, when used to direct integration of a plasmid to the benomyl resistance locus in a diploid cell, disrupted one of the beta-tubulin genes and concomitantly created a recessive lethal mutation, indicating that the single beta-tubulin gene of yeast has an essential function [18].
• Antibody response to preexposure human diploid-cell rabies vaccine given concurrently with chloroquine [19].
• The use of the polymerase chain reaction for analysing DNA sequences in individual diploid cells and human sperm shows that two genetic loci can be co-amplified from a single sperm, which may allow the analysis of previously inaccessible genetic phenomena [20].

Anatomical context of Diploidy

• Normal diploid human amniocytes were fused with differentiated mouse muscle cells by using polyethylene glycol [21].
• The growth of normal diploid fibroblasts is generally thought to be tightly controlled by exogenous growth factors such as platelet-derived growth factor (PDGF) and epidermal growth factor (EGF) [22].
• Regulated overexpression of YB-1 in drug-sensitive diploid breast epithelial cells induced MDR-1 gene expression and multidrug resistance [23].
• Haploid or diploid parthenogenones, resulting from spontaneous or experimental activation of unfertilized eggs, will undergo apparently normal preimplantation development but die in the early post-implantation stages [24].
• Analysis of human beta interferon (IFN) mRNA preparations obtained from poly(I) . poly (C)-induced human diploid fibroblasts (FS-4) and from several similarly induced human-mouse somatic cell hybrids by electrophoresis through agarose-CH3HgOH tube gels led to the detection of at least five translationally active human IFN-beta mRNA species [25].

Associations of Diploidy with chemical compounds

• Of 17 evaluable patients with unresectable hyperdiploid tumors, 15 had complete responses and two had partial responses to cyclophosphamide and doxorubicin; six others with diploid tumors did not respond (P = 0.00001) [26].
• Deletion of the diploid dihydrofolate reductase locus from cultured mammalian cells [27].
• To facilitate studies of folate metabolism and chemotherapy the sole dhfr-ts copy in a heterozygous deletion line was replaced, yielding lines that were functionally DHFR-TS-. Although most genes are diploid in trypanosomatids, methods exploiting the high frequency of homologous recombination should permit complete replacement of any parasite gene [28].
• Here it was shown that in diploids some of the same kinases and STE12 are required for filamentous growth, but the pheromone receptors and guanosine triphosphate-binding protein are not required for filament formation [29].
• Polyinosinic.polycytidylic acid [poly(I.C)] induced production of interferon by a strain of diploid human fibroblasts (FS-4), measured between 5 and 24 hours from induction, is enhanced up to 128-fold by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB), a reversible inhibitor of nuclear heterogeneous RNA synthesis [30].

Gene context of Diploidy

• Starvation for nitrogen further induced (6- to 8-fold) transcription of IME1, but, as expected, the induction was found only in MATa/MAT alpha or rme1-1/rme1-1 diploids [31].
• However, ras1 - ras2 - spores of doubly heterozygous diploids are incapable of resuming vegetative growth [32].
• Control of the initiation of meiosis was examined in diploids of yeast homozygous for two temperature-sensitive mutations, cyr1 and CYR3, which are defective in adenylate cyclase and cAMP-dependent protein kinase, respectively [17].
• Furthermore, ubi4/ubi4 diploids are sporulation-defective. ubi4 mutants are also hypersensitive to high temperatures, starvation, and amino acid analogs [33].
• We also studied the sporulation products of a diploid heterozygous at the HIS4 locus for an insertion of a 100 bp fragment of MATa containing the HO endonuclease cut site [34].

Analytical, diagnostic and therapeutic context of Diploidy

• However, the probability of disease-free survival in patients with diploid tumors and low S-phase fractions was 90 +/- 3 percent at five years, as compared with 70 +/- 13 percent in those with diploid tumors and high S-phase fractions (P = 0.007) [35].
• The nuclear DNA contents of erythrocytes (normal diploids, 2C) and tumor cells dispersed from the fixed tumor tissues were measured by 4',6-diamidino-2-phenylindole hydrochloride-DNA microfluorometry by using mouse cerebellar small granule cells (normal diploids, 2C) as a reference [36].
• Mannose-labeled glycopeptides from the surface of growing and nongrowing human diploid cells (KL-2) were separated into neutral glycopeptides and acidic glycopeptides by paper electrophoresis [37].
• Rapid clonal growth and serial passage of human diploid fibroblasts in a lipid-enriched synthetic medium supplemented with epidermal growth factor, insulin, and dexamethasone [38].
• Several hundred polypeptides from four human diploid fibroblast cell lines were compared by high-resolution two-dimensional polyacrylamide gel electrophoresis and double-label autoradiography under conditions where allelic products that differ by a single charged amino acid would be distinguished [39].

References