Dataset Information

Transcription-dependent radial distribution of TCF7L2 regulated genes in chromosome territories.

ABSTRACT: Human chromosomes occupy distinct territories in the interphase nucleus. Such chromosome territories (CTs) are positioned according to gene density. Gene-rich CTs are generally located in the center of the nucleus, while gene-poor CTs are positioned more towards the nuclear periphery. However, the association between gene expression levels and the radial positioning of genes within the CT is still under debate. In the present study, we performed three-dimensional fluorescence in situ hybridization experiments in the colorectal cancer cell lines DLD-1 and LoVo using whole chromosome painting probes for chromosomes 8 and 11 and BAC clones targeting four genes with different expression levels assessed by gene expression arrays and RT-PCR. Our results confirmed that the two over-expressed genes, MYC on chromosome 8 and CCND1 on chromosome 11, are located significantly further away from the center of the CT compared to under-expressed genes on the same chromosomes, i.e., DLC1 and SCN3B. When CCND1 expression was reduced after silencing the major transcription factor of the WNT/?-catenin signaling pathway, TCF7L2, the gene was repositioned and mostly detected in the interior of the CT. Thus, we suggest a non-random distribution in which over-expressed genes are located more towards the periphery of the respective CTs.

SUBMITTER: Torabi K

PROVIDER: S-EPMC7906436 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Transcription-dependent radial distribution of TCF7L2 regulated genes in chromosome territories.

Torabi Keyvan K Wangsa Darawalee D Ponsa Immaculada I Brown Markus M Bosch Anna A Vila-Casadesús Maria M Karpova Tatiana S TS Calvo Maria M Castells Antoni A Miró Rosa R Ried Thomas T Camps Jordi J

Chromosoma 20170325 5

Human chromosomes occupy distinct territories in the interphase nucleus. Such chromosome territories (CTs) are positioned according to gene density. Gene-rich CTs are generally located in the center of the nucleus, while gene-poor CTs are positioned more towards the nuclear periphery. However, the association between gene expression levels and the radial positioning of genes within the CT is still under debate. In the present study, we performed three-dimensional fluorescence in situ hybridizati ...[more]

PMID: 28343235

Similar Datasets

Project description:The chromatin of individual chromosomes is organized into chromosome territories (CTs) in the interphase nucleus. The spatial arrangement of CTs is non-random and evolutionarily conserved. The gene-dense and gene-poor CTs are positioned in the nuclear center and periphery, respectively. As candidates for key molecules involved in nuclear organization, we have investigated the nuclear actin-related proteins (Arps), which include the evolutionarily conserved actin-family together with conventional actin. We used a conditional knockout system with chicken DT40 cells to analyze the functions of the actin-related protein Arp6. Consistent with a previous identification of Arp6 in the SRCAP chromatin remodeling complex, the histone variant H2AZ was significantly decreased in the chromatin of Arp6-deficient cells. Most importantly, Arp6-deficient cells had impaired radial positioning of both gene-poor macrochromosome and gene-rich microchromosome CTs. A transcription microarray analysis of the cells suggests that the radial positioning of CTs impacts only a limited number of genes and plays an active role in repression, rather than in induction. As far as we know, this report is the first observation that an inner nuclear protein is required for the radial distribution of CTs, and will provide new insight into the mechanisms and physical significance of the positioning of CTs in the nucleus. The total RNA was extracted with RNeasy Maxi Kit (QIAGEN) according to the manufacturer protocol. The poly-A mRNA was isolated from total RNA using Oligotex-dT30 Super (JSR corporation) and biotinylated cRNA was synthesized according to Affymetrix GeneChip Expression Analysis Technical Manual (Affymetrix). Shortly, 2 ug of poly-A mRNA was reverse transcribed to cDNA using 100 pmol of a T7-Oligo (dT) Primer (Invitrogen), and biotinylated cRNA was prepared by in vitro transcription amplification. For hybridization, 15 ug of biotinylated cRNA was fragmented and added into a hybridization cocktail containing four biotinylated hybridization controls (bioB, bioC, bioD, and cre) as recommended by the manufacturer. GeneChip Chicken genome Arrays (Affymetrix) were hybridized with the cocktail at 45ËC for 16 hours. After washing with Non-Stringent wash buffer (6xSSPE, 0.01% Tween20) and staining with SAPE in the Affymetrix GeneChip Fluidics Station 400, the GeneChips were read using the Affymetrix GeneChip scanner 3000 7G. These systems and data analyses were operated with the GeneChip Operating Software 1.3.

Project description:BackgroundGene promoters have guided evolution processes for millions of years. It seems that they were the main engine responsible for the integration of different mutations favorable for the environmental conditions. In cooperation with different transcription factors and other biochemical components, these regulatory regions dictate the synthesis frequency of RNA molecules. Predominantly in the last decade, it has become clear that nuclear organization impacts upon gene regulation. To fully understand the connections between Homo sapiens chromosomes and their gene promoters, we analyzed 1200 promoter sequences using our Kappa Index of Coincidence method.ResultsIn order to measure the structural similarity of gene promoters, we used two-dimensional image-based patterns obtained through Kappa Index of Coincidence (Kappa IC) and (C+G)% values. The center of weight of each promoter pattern indicated a structure similarity between promoters of each chromosome. Furthermore, the proximity of chromosomes seems to be in accordance to the structural similarity of their gene promoters. The arrangement of chromosomes according to Kappa IC values of promoters, shows a striking symmetry between the chromosome length and the structure of promoters located on them. High Kappa IC and (C+G)% values of gene promoters were also directly associated with the most frequent genetic diseases. Taking into consideration these observations, a general hypothesis for the evolutionary dynamics of the genome has been proposed. In this hypothesis, heterochromatin and euchromatin domains exchange DNA sequences according to a difference in the rate of Slipped Strand Mispairing and point mutations.ConclusionsIn this paper we showed that gene promoters appear to be specific to each chromosome. Furthermore, the proximity between chromosomes seems to be in accordance to the structural similarity of their gene promoters. Our findings are based on comprehensive data from Transcriptional Regulatory Element Database and a new computer model whose core is using Kappa index of coincidence.

Dataset Information

Transcription-dependent radial distribution of TCF7L2 regulated genes in chromosome territories.

Publications

Transcription-dependent radial distribution of TCF7L2 regulated genes in chromosome territories.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets