Search results for "Gene dosage"
showing 10 items of 66 documents
Cytological and molecular characterization of three gametoclones of Citrus clementina
2013
Abstract Background Three gametoclonal plants of Citrus clementina Hort. ex Tan., cv. Nules, designated ESP, FRA, and ITA (derived from three labs in Spain, France, and Italy, respectively), were selected for cytological and molecular characterization in order to elucidate genomic rearrangements provoked by haploidization. The study included comparisons of their ploidy, homozygosity, genome integrity, and gene dosage, using chromosome counting, flow cytometry, SSR marker genotyping, and array-Comparative Genomic Hybridization (array-CGH). Results Chromosome counting and flow cytometry revealed that ESP and FRA were haploid, but ITA was tri-haploid. Homozygous patterns, represented by a sing…
Evolution of the immune system influences speciation rates in teleost fishes.
2016
Teleost fishes constitute the most species-rich vertebrate clade and exhibit extensive genetic and phenotypic variation, including diverse immune defense strategies. The genomic basis of a particularly aberrant strategy is exemplified by Atlantic cod, in which a loss of major histocompatibility complex (MHC) II functionality coincides with a marked expansion of MHC I genes. Through low-coverage genome sequencing (9–39×), assembly and comparative analyses for 66 teleost species, we show here that MHC II is missing in the entire Gadiformes lineage and thus was lost once in their common ancestor. In contrast, we find that MHC I gene expansions have occurred multiple times, both inside and outs…
Genomic Imprinting and the Regulation of Postnatal Neurogenesis
2017
Most genes required for mammalian development are expressed from both maternally and paternally inherited chromosomal homologues. However, there are a small number of genes known as “imprinted genes” that only express a single allele from one parent, which is repressed on the gene from the other parent. Imprinted genes are dependent on epigenetic mechanisms such as DNA methylation and post-translational modifications of the DNA-associated histone proteins to establish and maintain their parental identity. In the brain, multiple transcripts have been identified which show parental origin-specific expression biases. However, the mechanistic relationship with canonical imprinting is unknown. R…
Conserved Organisation of 45S rDNA Sites and rDNA Gene Copy Number among Major Clades of Early Land Plants
2016
Genes encoding ribosomal RNA (rDNA) are universal key constituents of eukaryotic genomes, and the nuclear genome harbours hundreds to several thousand copies of each species. Knowledge about the number of rDNA loci and gene copy number provides information for comparative studies of organismal and molecular evolution at various phylogenetic levels. With the exception of seed plants, the range of 45S rDNA locus (encoding 18S, 5.8S and 26S rRNA) and gene copy number variation within key evolutionary plant groups is largely unknown. This is especially true for the three earliest land plant lineages Marchantiophyta (liverworts), Bryophyta (mosses), and Anthocerotophyta (hornworts). In this work…
Cohesin-dependent regulation of gene expression during differentiation is lost in cohesin-mutated myeloid malignancies.
2019
Cohesin complex disruption alters gene expression, and cohesin mutations are common in myeloid neoplasia, suggesting a critical role in hematopoiesis. Here, we explore cohesin dynamics and regulation of hematopoietic stem cell homeostasis and differentiation. Cohesin binding increases at active regulatory elements only during erythroid differentiation. Prior binding of the repressive Ets transcription factor Etv6 predicts cohesin binding at these elements and Etv6 interacts with cohesin at chromatin. Depletion of cohesin severely impairs erythroid differentiation, particularly at Etv6-prebound loci, but augments self-renewal programs. Together with corroborative findings in acute myeloid le…
Detection of MET Alterations Using Cell Free DNA and Circulating Tumor Cells from Cancer Patients
2020
MET alterations may provide a potential biomarker to evaluate patients who will benefit from treatment with MET inhibitors. Therefore, the purpose of the present study is to investigate the utility of a liquid biopsy-based strategy to assess MET alterations in cancer patients. We analyzed MET amplification in circulating free DNA (cfDNA) from 174 patients with cancer and 49 healthy controls and demonstrated the accuracy of the analysis to detect its alteration in patients. Importantly, a significant correlation between cfDNA concentration and MET copy number (CN) in cancer patients (r = 0.57, p <
Dlk1 dosage regulates hippocampal neurogenesis and cognition
2021
Significance Generation of new neurons occurs normally in the adult brain in two locations: the subventricular zone (SVZ) in the walls of the lateral ventricles and the subgranular zone (SGZ) in the dentate gyrus (DG) of the hippocampus. Neurogenesis in the adult hippocampus has been implicated in cognitive functions such as learning, memory, and recovery of stress response. Imprinted genes are highly prevalent in the brain and have adult and developmental important functions. Genetic deletion of the imprinted gene Dlk1 from either parental allele shows that DLK1 is a key mediator of quiescence in adult hippocampal NSCs. Additionally, Dlk1 is exquisitely dosage sensitive in the brain with p…
Comparative genetic study of intratumoral heterogenous MYCN amplified neuroblastoma versus aggressive genetic profile neuroblastic tumors.
2016
Intratumoral heterogeneous MYCN amplification (hetMNA) is an unusual event in neuroblastoma with unascertained biological and clinical implications. Diagnosis is based on the detection of MYCN amplification surrounded by non-amplified tumor cells by fluorescence in situ hybridization (FISH). To better define the genetic features of hetMNA tumors, we studied the Spanish cohort of neuroblastic tumors by FISH and single nucleotide polymorphism arrays. We compared hetMNA tumors with homogeneous MNA (homMNA) and nonMNA tumors with 11q deletion (nonMNA w11q-). Of 1091 primary tumors, 28 were hetMNA by FISH. Intratumoral heterogeneity of 1p, 2p, 11q and 17q was closely associated with hetMNA tumor…
Mitochondrial DNA copy number and telomere length in peripheral blood mononuclear cells in comparison with whole blood in three different age groups
2019
There are more and more studies on telomere length (TL) and mitochondrial DNA (mtDNA), and it has been proven that these factors play a significant role in the aging of the immune system thereby it is important to understand how it varies in different cell types for more accurate conclusions. The aim of this study was to look into dynamics of mtDNA amount in conjunction with TL in peripheral blood mononuclear cells (PBMC) during aging in comparison with whole blood (WB) cells. Overall, 53 samples were divided into three age groups: 20-39 year age group, 40-59 year age group and 60-79 year age group. MtDNA amount was determined by qPCR TaqMan, and TL was measured by Southern blotting of term…
Alteration of major vault protein in human glioblastoma and its relation with EGFR and PTEN status.
2014
Glioblastoma (GBM) is the most frequent and malignant primary brain tumor. Conventional therapy of surgical removal, radiation and chemotherapy is largely palliative. Major vault protein (MVP), the main component of the vault organelle has been associated with multidrug resistance by reducing cellular accumulation of chemotherapeutic agents. With regard to cancer, MVP has been shown to be overexpressed in drug resistance development and malignant progression. The aim of the present study was to evaluate the MVP gene dosage levels in 113 archival samples from GBM and its correlation with patients' survival and epidermal growth factor receptor (EGFR) and phosphatase and tensin homolog (PTEN) …