Search results for "Ploidy"

Clastogenic and aneuploidizing effects of antiblastic busulphan revealed by kinetochore immunofluorescence in CHO cells.

1991

We utilized, in CHO cells, the cytoplasm preservation technique to evaluate the micronucleus frequency at different busulphan concentrations, and the indirect immunofluorescence technique, using sera obtained from patients with scleroderma (CREST variant), to analyze if busulphan-induced micronuclei have kinetochores. Results show that this alkylating agent is capable of causing a significant increase of micronuclei in vitro, a great part (40%) of them having CREST-positive kinetochores. These findings confirm the clastogenic effect of busulphan and reveal a considerable capability of this agent to induce aneuploidy. These results are examined taking into account the high incidence of secon…

<p class="HeadingRunIn"><strong><em>Charybdis glaucophylla</em> (Asparagaceae), a new species from Sardinia</strong>&lt…

2012

Charybdis glaucophylla (Asparagaceae), a new species from Sardinia, is described and illustrated. It is a diploid species with 2n = 20 chromosomes growing along the rocky coast, sandy dunes and mountain top in the south-western part of the island. Within the genus, this species results taxonomically well isolated and differentiated due to relevant morphological and phenological features, such as the leaves wide and short, very rigid and glaucous-pruinose, as well as the very late foliation (winter). It shows only some relationships with C. pancration for the whitish bulb tunics and the diploid chromosome complement, and with C. maura and C. aphylla due to the glaucous leaves.

Congenital hypopituitarism and multiple midline defects in a newborn with non-familial Cat Eye syndrome

2022

Abstract Background Cat eye syndrome (CES) is a rare chromosomal disease, with estimated incidence of about 1 in 100,000 live newborns. The classic triad of iris coloboma, anorectal malformations, and auricular abnormalities is present in 40% of patients, and other congenital defects may also be observed. The typical associated cytogenetic anomaly relies on an extra chromosome, derived from an inverted duplication of short arm and proximal long arm of chromosome 22, resulting in partial trisomy or tetrasomy of such regions (inv dup 22pter-22q11.2). Case presentation We report on a full-term newborn, referred to us soon after birth. Physical examination showed facial dysmorphisms, including …

Chemotactic migration of human diploid fibroblasts is inhibited by contactinhibin.

1992

Gametic embryogenesis and haploid technology as valuable support to plant breeding

2011

Plant breeding is focused on continuously increasing crop production to meet the needs of an ever-growing world population, improving food quality to ensure a long and healthy life and address the problems of global warming and environment pollution, together with the challenges of developing novel sources of biofuels. The breeders' search for novel genetic combinations, with which to select plants with improved traits to satisfy both farmers and consumers, is endless. About half of the dramatic increase in crop yield obtained in the second half of the last century has been achieved thanks to the results of genetic improvement, while the residual advance has been due to the enhanced managem…

The role of reactive oxygen species and subsequent DNA-damage response in the emergence of resistance towards resveratrol in colon cancer models

2014

AbstractIn spite of the novel strategies to treat colon cancer, mortality rates associated with this disease remain consistently high. Tumour recurrence has been linked to the induction of resistance towards chemotherapy that involves cellular events that enable cancer cells to escape cell death. Treatment of colon cancer mainly implicates direct or indirect DNA-damaging agents and increased repair or tolerances towards subsequent lesions contribute to generate resistant populations. Resveratrol (RSV), a potent chemosensitising polyphenol, might share common properties with chemotherapeutic drugs through its indirect DNA-damaging effects reported in vitro. In this study, we investigated how…

Aneuploid IMR90 cells induced by depletion of pRB, DNMT1 and MAD2 show a common gene expression signature

2019

Chromosome segregation defects lead to aneuploidy which is a major feature of solid tumors. How diploid cells face chromosome mis-segregation and how aneuploidy is tolerated in tumor cells are not completely defined yet. Thus, an important goal of cancer genetics is to identify gene networks that underlie aneuploidy and are involved in its tolerance. To this aim, we induced aneuploidy in IMR90 human primary cells by depleting pRB, DNMT1 and MAD2 and analyzed their gene expression profiles by microarray analysis. Bioinformatic analysis revealed a common gene expression profile of IMR90 cells that became aneuploid. Gene Set Enrichment Analysis (GSEA) also revealed gene-sets/pathways that are …

DNA integrity, growth pattern, spindle formation, chromosomal constitution and imprinting patterns of mouse oocytes from vitrified pre-antral follicl…

2010

Cryopreservation of follicles for culture and oocyte growth and maturation in vitro provides an option to increase the number of fertilizable oocytes and restore fertility in cases where transplantation of ovarian tissue poses a risk for malignant cell contamination. Vitrification for cryopreservation is fast and avoids ice crystal formation. However, the influences of exposure to high concentrations of cryoprotectants on follicle development, oocyte growth and maturation, and particularly, on the DNA integrity and methylation imprinting has not been studied systematically. Follicle survival and development, DNA damage, oocyte growth patterns, maturation, spindle formation and chromosomal c…

Functional Inactivation of pRB Results in Aneuploid Mammalian Cells After Release From a Mitotic Block

2002

AbstractThe widespread chromosome instability observed in tumors and in early stage carcinomas suggests that aneuploidy could be a prerequisite for cellular transformation and tumor initiation. Defects in tumor suppressers and genes that are part of mitotic checkpoints are likely candidates for the aneuploid phenotype. By using flow cytometric, cytogenetic, immunocytochemistry techniques we investigated whether pRB deficiency could drive perpetual aneuploidy in normal human and mouse fibroblasts after mitotic checkpoint challenge by microtubule-destabilizing drugs. Both mouse and human pRB-deficient primary fibroblasts resulted, upon release from a mitotic block, in proliferating aneuploid …

Asynchronous replication dynamics of imprinted and non-imprinted chromosome regions in early mouse embryos.

2008

We have used interphase FISH to analyze the replication behavior of four imprinted chromosome regions (Snrpn, Zim1-Peg3, Dlk1-Gtl2, and Igf2r) and five non-imprinted regions in mouse one-cell to morula-stage embryos and embryonic fibroblasts. In general, imprinted chromosome regions showed the expected asynchronous pattern of replication throughout all analyzed stages of preimplantation development and in differentiated cells. The Dlk1-Gtl2 locus which is not expressed and Igf2r which is biallelically expressed in early embryos showed a relaxation of replication asynchrony at the morula stage. Asynchronous replication in zygotes and two-cell embryos was not specific to imprinted regions. Th…