Search results for "chromosome"
showing 10 items of 1175 documents
Moderate ovarian stimulation does not increase the incidence of human embryo chromosomal abnormalities in in vitro fertilization cycles.
2012
A high chromosomal abnormalities rate has been observed in human embryos derived from in vitro fertilization (IVF) treatments. The real incidence in natural cycles has been poorly studied, so whether this frequency may be induced by external factors, such as use of gonadotropins for ovarian stimulation, remains unknown.We conducted a prospective cohort study in a University-affiliated private infertility clinic with a comparison between unstimulated and stimulated ovarian cycles in the same women. Preimplantation genetic screening by fluorescence in situ hybridization was performed in all viable d 3 embryos.The primary objective was to compare the incidence of embryo chromosomal abnormaliti…
Changes in sex ratio from fertilization to birth in assisted-reproductive-treatment cycles
2014
Background: In Western gender-neutral countries, the sex ratio at birth is estimated to be approximately 1.06. This ratio is lower than the estimated sex ratio at fertilization which ranges from 1.07 to 1.70 depending on the figures of sex ratio at birth and differential embryo/fetal mortality rates taken into account to perform these estimations. Likewise, little is known about the sex ratio at implantation in natural and assisted-reproduction-treatment (ART) cycles. In this bioessay, we aim to estimate the sex ratio at fertilization and implantation using data from embryos generated by standard in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) in preimplantation gene…
A trans-acting locus regulates an anti-viral expression network and type 1 diabetes risk
2010
Combined analyses of gene networks and DNA sequence variation can provide new insights into the aetiology of common diseases that may not be apparent from genome-wide association studies alone. Recent advances in rat genomics are facilitating systems-genetics approaches. Here we report the use of integrated genome-wide approaches across seven rat tissues to identify gene networks and the loci underlying their regulation. We defined an interferon regulatory factor 7 (IRF7)-driven inflammatory network (IDIN) enriched for viral response genes, which represents a molecular biomarker for macrophages and which was regulated in multiple tissues by a locus on rat chromosome 15q25. We show that Epst…
Structure and evolution of the leucine plasmids carried by the endosymbiont (Buchnera aphidicola) from aphids of the family Aphididae.
1998
In all examined species of the family Aphididae, the bacterial endosymbiont Buchnera aphidicola carries a plasmid encoding the genes leuABCD (involved in leucine biosynthesis) along with repA1, repA2 and ORF1. The gene organisation of the leucine plasmids was conserved, except in Buchnera isolated from Pterocomma populeum, where ORF1 was located in a different position. An inverted repeat (LIR1) located between repA2 and leuA is found in all of the Buchnera leucine plasmids examined. The predicted secondary structure of the LIR1 transcript conforms to a long hairpin loop, suggesting an involvement in transcription termination or messenger stability. Phylogenetic reconstruction based on repA…
Concentration-Dependent Protection by Ethanol Extract ofPropolis against γ
2011
[EN] Radioprotection with natural products may be relevant to the mitigation of ionizing radiation-induced damage in mammalian systems; in this sense, propolis extracts have shown effects such as antioxidant, antitumoral, anti-inflammatory, and immunostimulant. We report for the first time a cytogenetic study to evaluate the radioprotective effect, in vitro, of propolis against radiation-induced chromosomal damage. Lymphocytes were cultured with increasing concentrations of ethanol extract of propolis (EEP), including 20, 40, 120, 250, 500, 750, 1000, and 2000 ¿g mL-1 and then exposed to 2 Gy ¿-rays. A significant and concentration-dependent decrease is observed in the frequency of chromoso…
Cytogenetic characterization of HB2 epithelial cells from the human breast.
2014
HB2 is a cell line originated by subcloning of MTSV1-7 mammary luminal epithelial cells isolated from human milk and immortalization via introduction of the gene encoding simian virus 40 (SV40) large T antigen. Despite its wide utilization as non-neoplastic counterpart in assays aimed to elucidating various biochemical and genetical aspects of normal and tumoral breast cells, to our knowledge no literature data have so far appeared concerning the chromosomal characterization of the HB2 cells. Here, we report the cytogenetic characterization of the karyotype of HB2 cells, which puts in evidence the occurrence of changes in chromosomal number and structure and the presence of unidentified chr…
A region on human chromosome 4 (q35.1→qter) induces senescence in cell hybrids and is involved in cervical carcinogenesis
2005
Human papillomavirus (HPV) types 16 and 18 are known to play a major role in cervical carcinogenesis. Additional genetic alterations are required for the development and progression of cervical cancer. Previously, we showed that the introduction of an entire human chromosome 4 into HPV-immortalized cells by microcell-mediated chromosome transfer (MMCT) can induce senescence in cell hybrids. In the present study, we established eight new murine donor cell lines harboring different fragments of the human chromosome 4. These were tested for their ability to induce senescence by MMCT into HPV16-immortalized keratinocytes (HPK II) and cervical carcinoma cells (HeLa). By exclusion, we could ident…
The stem rust resistance gene Rpg5 encodes a protein with nucleotide-binding-site, leucine-rich, and protein kinase domains
2008
We isolated the barley stem rust resistance genes Rpg5 and rpg4 by map-based cloning. These genes are colocalized on a 70-kb genomic region that was delimited by recombination. The Rpg5 gene consists of an unusual structure encoding three typical plant disease resistance protein domains: nucleotide-binding site, leucine-rich repeat, and serine threonine protein kinase. The predicted RPG5 protein has two putative transmembrane sites possibly involved in membrane binding. The gene is expressed at low but detectable levels. Posttranscriptional gene silencing using VIGS resulted in a compatible reaction with a normally incompatible stem rust pathogen. Allele sequencing also validated the candi…
Direct observation of frequency modulated transcription in single cells using light activation
2013
Single-cell analysis has revealed that transcription is dynamic and stochastic, but tools are lacking that can determine the mechanism operating at a single gene. Here we utilize single-molecule observations of RNA in fixed and living cells to develop a single-cell model of steroid-receptor mediated gene activation. We determine that steroids drive mRNA synthesis by frequency modulation of transcription. This digital behavior in single cells gives rise to the well-known analog dose response across the population. To test this model, we developed a light-activation technology to turn on a single steroid-responsive gene and follow dynamic synthesis of RNA from the activated locus. DOI: http:/…
Allium albanicum (Amaryllidaceae), a new species from Balkans and its relationships with A. meteoricum Heldr. & Hausskn. ex Halácsy
2019
A new species, Alliumalbanicum, is described and illustrated from Albania (Balkan Peninsula). It grows on serpentines or limestone in open rocky stands with a scattered distribution, mainly in mountain locations. Previously, the populations of this geophyte were attributed to A.meteoricum Heldr. & Hausskn. ex Halácsy, described from a few localities of North and Central Greece. These two species indeed show close relationships, chiefly regarding some features of the spathe valves, inflorescence and floral parts. They also share the same diploid chromosome number 2n =16 and similar karyotype, while seed testa micro-sculptures and leaf anatomy reveal remarkable differences. There are …