Search results for "Chromosomes"
showing 10 items of 509 documents
Are There Knots in Chromosomes?
2017
Recent developments have for the first time allowed the determination of three-dimensional structures of individual chromosomes and genomes in nuclei of single haploid mouse embryonic stem (ES) cells based on Hi⁻C chromosome conformation contact data. Although these first structures have a relatively low resolution, they provide the first experimental data that can be used to study chromosome and intact genome folding. Here we further analyze these structures and provide the first evidence that G1 phase chromosomes are knotted, consistent with the fact that plots of contact probability vs sequence separation show a power law dependence that is intermediate between that of a fractal globule …
Chromosomal distribution of interstitial telomeric sequences in nine neotropical primates (Platyrrhini): possible implications in evolution and phylo…
2016
To localize interstitial telomeric sequences (ITSs) and to test whether their pattern of distribution could be linked to chromosomal evolution, we hybridized telomeric sequence probes (peptide nucleic acid, PNA) on metaphases of New World monkeys: Callithrix argentata, Callithrix jacchus, Cebuella pygmaea, Saguinus oedipus, Saimiri sciureus, Aotus lemurinus griseimembra, Aotus nancymaae (Cebidae), Lagothrix lagotricha (Atelidae) and Callicebus moloch (Pithecidae), characterized by a rapid radiation and a high rate of chromosomal rearrangements. Our analysis of the probe signal localization allowed us to show in all the species analysed, as normally, the telomeric location at the terminal en…
The cholinergic system in Down's syndrome
2006
The cholinergic system is one of the most important modulatory neurotransmitter systems in the brain. Alterations of the transmission communicators are accompanied by reduction of the cortical activity, which is associated with a learning and memory deficit. Down's syndrome is a pathological condition characterized by a high number of abnormalities that involve the brain.The cholinergic system is involved in alterations of the neurological system such as severe learning difficulties.To explain these alterations, important results are obtained from studies about murine trisomy 16 (animal model of Down's syndrome).The results obtained provide useful elements in the improvement of knowledge ab…
Paternal uniparental disomy chromosome 14-like syndrome due a maternal de novo 160 kb deletion at the 14q32.2 region not encompassing the IG- and the…
2015
The human chromosome 14q32 carries a cluster of imprinted genes which include the paternally expressed genes (PEGs) DLK1 and RTL1, as well as the maternally expressed genes (MEGs) MEG3, RTL1as, and MEG8. PEGs and MEGs expression at the 14q32.2-imprinted region are regulated by two differentially methylated regions (DMRs): the IG-DMR and the MEG3-DMR, which are respectively methylated on the paternal and unmethylated on the maternal chromosome 14 in most cells. Genetic and epigenetic abnormalities affecting these imprinted gene clusters result in two different phenotypes currently known as maternal upd(14) syndrome and paternal upd(14) syndrome. However, only few patients carrying a maternal…
Chromosomal changes in renal oncocytomas Evidence that t(5;11)(q35;q13) may characterize a second subgroup of oncocytomas
1995
Many of the reported oncocytomas have different chromosome abnormalities, indicating that they comprise a cytogenetically heterogenous group of tumors consisting of potentially cytogenetic subgroups. We have performed cytogenetic studies on nine renal oncocytomas. Clonal abnormalities were present in eight tumors. The findings most observed were the loss of the Y chromosome, and abnormalities of chromosomes 1 and 22. We also observed telomeric associations (tas) in two tumors and structural aberrations of chromosomes 9p and 19q, as well as monosomy 10. In two cases we found a similar reciprocal t(5;11)(q35;q13) in two cases. Review of the literature disclosed one other oncocytoma with a t(5…
Exome Sequencing Reveals VCP Mutations as a Cause of Familial ALS
2010
Summary Using exome sequencing, we identified a p.R191Q amino acid change in the valosin-containing protein ( VCP ) gene in an Italian family with autosomal dominantly inherited amyotrophic lateral sclerosis (ALS). Mutations in VCP have previously been identified in families with Inclusion Body Myopathy, Paget disease, and Frontotemporal Dementia (IBMPFD). Screening of VCP in a cohort of 210 familial ALS cases and 78 autopsy-proven ALS cases identified four additional mutations including a p.R155H mutation in a pathologically proven case of ALS. VCP protein is essential for maturation of ubiquitin-containing autophagosomes, and mutant VCP toxicity is partially mediated through its effect on…
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…
False positive rate of an arrayCGH platform for single-cell preimplantation genetic screening and subsequent clinical application on day-3
2013
In this work, false positive rate of an arrayCGH platform for its use in day-3 single-blastomere analysis was calculated. For this purpose, 38 embryos diagnosed as abnormal on day-3 by FISH were re-biopsied on day-4. Single-cell day-4 arrayCGH diagnosis was then performed. A successful amplification was obtained in 97.4 % (37/38) of the day-4 cells analysed by arrayCGH. Day-3 FISH and day-4 arrayCGH diagnosis were concordant in 35/37 cases. The two discordant embryos were spread and all the cells from each embryo were re-analysed by FISH on day 5. The same error rate (2.7 %) for day-3 FISH and day-4 arrayCGH was obtained when comparing day-5 FISH re-analysis. After this pre-clinical phase, …
Aceruloplasminaemia: a family with a novel mutation and long-term therapy with deferasirox.
2014
Ceruloplasmin is a member of the multicopper oxidase family that plays a major role in the transport of iron in the body. Aceruloplasminaemia (ACP) is a rare disease and is clinically identified by iron overload in liver, pancreas, brain, and other organs, and by microcytic anaemia. So far, the iron chelator deferasirox was given for therapy only up to 6 months due to side effects. Here, we describe a novel mutation leading to ACP and report for the first time a long-term therapy, that is, 2 years with deferasirox. ACP was diagnosed in 3 siblings using clinical and biochemical characteristics, HFE and ceruloplasmin mutational analysis, liver biopsy, brain-, liver-, and heart-MRI. For iron d…
A genome-wide association study identifies two loci associated with heart failure due to dilated cardiomyopathy
2011
Dilated cardiomyopathy (DCM) is a major cause of heart failure with a high familial recurrence risk. So far, the genetics of DCM remains largely unresolved. We conducted the first genome-wide association study (GWAS) to identify loci contributing to sporadic DCM.One thousand one hundred and seventy-nine DCM patients and 1108 controls contributed to the discovery phase. Pools of DNA stratified on disease status, population, age, and gender were constituted and used for testing association of DCM with 517 382 single nucleotide polymorphisms (SNPs). Three DCM-associated SNPs were confirmed by individual genotyping (P5.0 10(-7)), and two of them, rs10927875 and rs2234962, were replicated in ind…