scholarly journals A Resource for the Allele-Specific Analysis of DNA Methylation at Multiple Genomically Imprinted Loci in Mice

2017 ◽  
Author(s):  
Jadiel A. Wasson ◽  
Onur Birol ◽  
David J. Katz

AbstractGenomically imprinted loci are expressed mono-allelically dependent upon the parent of origin. Their regulation not only illuminates how chromatin regulates gene expression but also how chromatin can be reprogrammed every generation. Because of their distinct parent of origin regulation, analysis of imprinted loci can be difficult. Single nucleotide polymorphisms (SNPs) are required to accurately assess these elements allele-specifically. However, publicly available SNP databases lack robust verification, making analysis of imprinting difficult. In addition, the allele-specific imprinting assays that have been developed employ different mouse strains, making it difficult to systemically analyze these loci. Here, we have generated a resource that will allow the allele-specific analysis of many significant imprinted loci in a single hybrid strain of Mus musculus. This resource includes verification of SNPs present within ten of the most widely used imprinting control regions and allele-specific DNA methylation assays for each gene in a C57BL/6J and CAST/EiJ hybrid strain background.

2018 ◽  
Author(s):  
Sahar V. Mozaffari ◽  
Michelle M. Stein ◽  
Kevin M. Magnaye ◽  
Dan L. Nicolae ◽  
Carole Ober

AbstractGenomic imprinting is the phenomena that leads to silencing of one copy of a gene inherited from a specific parent. Mutations in imprinted regions have been involved in diseases showing parent of origin effects. Identifying genes with evidence of parent of origin expression patterns in family studies allows the detection of more subtle imprinting. Here, we use allele specific expression in lymphoblastoid cell lines from 306 Hutterites related in a single pedigree to provide formal evidence for parent of origin effects. We take advantage of phased genotype data to assign parent of origin to RNA-seq reads in individuals with gene expression data. Our approach identified known imprinted genes, two putative novel imprinted genes, and 14 genes with asymmetrical parent of origin gene expression. We used gene expression in peripheral blood leukocytes (PBL) to validate our findings, and then confirmed imprinting control regions (ICRs) using DNA methylation levels in the PBLs.Author SummaryLarge scale gene expression studies have identified known and novel imprinted genes through allele specific expression without knowing the parental origins of each allele. Here, we take advantage of phased genotype data to assign parent of origin to RNA-seq reads in 306 individuals with gene expression data. We identified known imprinted genes as well as two novel imprinted genes in lymphoblastoid cell line gene expression. We used gene expression in PBLs to validate our findings, and DNA methylation levels in PBLs to confirm previously characterized imprinting control regions that could regulate these imprinted genes.


eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Daniela Pignatta ◽  
Robert M Erdmann ◽  
Elias Scheer ◽  
Colette L Picard ◽  
George W Bell ◽  
...  

Imprinted gene expression occurs during seed development in plants and is associated with differential DNA methylation of parental alleles, particularly at proximal transposable elements (TEs). Imprinting variability could contribute to observed parent-of-origin effects on seed development. We investigated intraspecific variation in imprinting, coupled with analysis of DNA methylation and small RNAs, among three Arabidopsis strains with diverse seed phenotypes. The majority of imprinted genes were parentally biased in the same manner among all strains. However, we identified several examples of allele-specific imprinting correlated with intraspecific epigenetic variation at a TE. We successfully predicted imprinting in additional strains based on methylation variability. We conclude that there is standing variation in imprinting even in recently diverged genotypes due to intraspecific epiallelic variation. Our data demonstrate that epiallelic variation and genomic imprinting intersect to produce novel gene expression patterns in seeds.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Joseph Tomlinson ◽  
Shawn W. Polson ◽  
Jing Qiu ◽  
Juniper A. Lake ◽  
William Lee ◽  
...  

AbstractDifferential abundance of allelic transcripts in a diploid organism, commonly referred to as allele specific expression (ASE), is a biologically significant phenomenon and can be examined using single nucleotide polymorphisms (SNPs) from RNA-seq. Quantifying ASE aids in our ability to identify and understand cis-regulatory mechanisms that influence gene expression, and thereby assist in identifying causal mutations. This study examines ASE in breast muscle, abdominal fat, and liver of commercial broiler chickens using variants called from a large sub-set of the samples (n = 68). ASE analysis was performed using a custom software called VCF ASE Detection Tool (VADT), which detects ASE of biallelic SNPs using a binomial test. On average ~ 174,000 SNPs in each tissue passed our filtering criteria and were considered informative, of which ~ 24,000 (~ 14%) showed ASE. Of all ASE SNPs, only 3.7% exhibited ASE in all three tissues, with ~ 83% showing ASE specific to a single tissue. When ASE genes (genes containing ASE SNPs) were compared between tissues, the overlap among all three tissues increased to 20.1%. Our results indicate that ASE genes show tissue-specific enrichment patterns, but all three tissues showed enrichment for pathways involved in translation.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Erika Calvano Küchler ◽  
Agnes Schröder ◽  
Vinicius Broska Teodoro ◽  
Ute Nazet ◽  
Rafaela Scariot ◽  
...  

Abstract Background This study aimed to investigate, if different physiological concentrations of vitamin D (25(OH)D3) and single nucleotide polymorphisms in vitamin D receptor (VDR) gene have an impact on gene expression in human periodontal ligament (hPDL) fibroblasts induced by simulated orthodontic compressive strain. Methods A pool of hPDL fibroblasts was treated in absence or presence of 25(OH)D3 in 3 different concentrations (10, 40 and 60 ng/ml). In order to evaluate the role of single nucleotide polymorphisms in the VDR gene, hPDL fibroblasts from 9 patients were used and treated in absence or presence of 40 ng/ml 25(OH)D3. Each experiment was performed with and without simulated orthodontic compressive strain. Real-time PCR was used for gene expression and allelic discrimination analysis. Relative expression of dehydrocholesterol reductase (DHCR7), Sec23 homolog A, amidohydrolase domain containing 1 (AMDHD1), vitamin D 25-hydroxylase (CYP2R1), Hydroxyvitamin D-1-α hydroxylase, receptor activator of nuclear factor-κB ligand (RANKL), osteoprotegerin (OPG), cyclooxygenase-2 (COX-2) and interleukin-6 (IL6) was assessed. Three single nucleotide polymorphisms in VDR were genotyped. Parametric or non-parametric tests were used with an alpha of 5%. Results RANKL, RANKL:OPG ratio, COX-2, IL-6, DHCR7, CYP2R1 and AMDHD1 were differentially expressed during simulated orthodontic compressive strain (p < 0.05). The RANKL:OPG ratio was downregulated by all concentrations (10 ng/ml, 40 ng/ml and 60 ng/ml) of 25(OH)D3 (mean = 0.96 ± 0.68, mean = 1.61 ± 0.66 and mean = 1.86 ± 0.78, respectively) in comparison to the control (mean 2.58 ± 1.16) (p < 0.05). CYP2R1 gene expression was statistically modulated by the different 25(OH)D3 concentrations applied (p = 0.008). Samples from individuals carrying the GG genotype in rs739837 presented lower VDR mRNA expression and samples from individuals carrying the CC genotype in rs7975232 presented higher VDR mRNA expression (p < 0.05). Conclusions Simulated orthodontic compressive strain and physiological concentrations of 25(OH)D3 seem to regulate the expression of orthodontic tooth movement and vitamin-D-related genes in periodontal ligament fibroblasts in the context of orthodontic compressive strain. Our study also suggests that single nucleotide polymorphisms in the VDR gene regulate VDR expression in periodontal ligament fibroblasts in the context of orthodontic compressive strain.


2021 ◽  
Vol 49 (5) ◽  
pp. 030006052110148
Author(s):  
Xue Qiao ◽  
Xing Niu ◽  
Jiayi Liu ◽  
Lijie Chen ◽  
Yan Guo ◽  
...  

Ameloblastoma is a common odontogenic epithelial tumor that exhibits various biological behaviors, ranging from simple cystic expansion to aggressive solid masses characterized by local invasiveness, a high risk of recurrence, and even malignant transformation. We report on two cases of unusually large solid ameloblastomas. We detected epithelial–mesenchymal transition-related gene expression and HRAS gene single nucleotide polymorphisms, providing possible molecular evidence of mesenchymal morphological changes in ameloblastoma. The detailed analysis of the pathogenesis of these two cases of ameloblastoma may deepen our understanding of this rare disease and offer promising targets for future targeted therapy.


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