Subcellular genomics shows pervasive within-mitochondrion single nucleotide variant heteroplasmy as revealed by single mitochondrion sequencing
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE107115 | GEO | 2017/12/15
SECONDARY ACCESSION(S): PRJNA419581
REPOSITORIES: GEO
Similar Datasets
Project description:A number of mitochondrial diseases arise from single-nucleotide variant (SNV) accumulation in multiple mitochondria. Here, we present a method for identification of variants present at the single-mitochondrion level in individual mouse and human neuronal cells, allowing for extremely high-resolution study of mitochondrial mutation dynamics. We identified extensive heteroplasmy between individual mitochondrion, along with three high-confidence variants in mouse and one in human that were present in multiple mitochondria across cells. The pattern of variation revealed by single-mitochondrion data shows surprisingly pervasive levels of heteroplasmy in inbred mice. Distribution of SNV loci suggests inheritance of variants across generations, resulting in Poisson jackpot lines with large SNV load. Comparison of human and mouse variants suggests that the two species might employ distinct modes of somatic segregation. Single-mitochondrion resolution revealed mitochondria mutational dynamics that we hypothesize to affect risk probabilities for mutations reaching disease thresholds.
| S-EPMC5771502 | biostudies-literature
Project description:Subcellular genomics shows pervasive within-mitochondrion single nucleotide variant heteroplasmy as revealed by single mitochondrion sequencing
| PRJNA419581 | ENA
Project description:BACKGROUND: Mitochondrial (mt) heteroplasmy can cause adverse biological consequences when deleterious mtDNA mutations accumulate disrupting ‘normal’ mt-driven processes and cellular functions. To investigate the heteroplasmy of such mtDNA changes we developed a moderate throughput mt isolation procedure to quantify the mt single-nucleotide variant (SNV) landscape in individual mouse neurons and astrocytes In this study we amplified mt-genomes from 1,645 single mitochondria (mts) isolated from mouse single astrocytes and neurons to 1. determine the distribution and proportion of mt-SNVs as well as mutation pattern in specific target regions across the mt-genome,2. assess differences in mtDNA SNVs between neurons and astrocytes, and 3. Study cosegregation of variants in the mouse mtDNA. RESULTS: 1. The data show that specific sites of the mt-genome are permissive to SNV presentation while others appear to be under stringent purifying selection. Nested hierarchical analysis at the levels of mitochondrion, cell, and mouse reveals distinct patterns of inter- and intra-cellular variation for mt-SNVs at different sites. 2. Further, differences in the SNV incidence were observed between mouse neurons and astrocytes for two mt-SNV 9027:G>A and 9419:C>T showing variation in the mutational propensity between these cell types. Purifying selection was observed in neurons as shown by the Ka/Ks statistic, suggesting that neurons are under stronger evolutionary constraint as compared to astrocytes. 3. Intriguingly, these data show strong linkage between the SNV sites at nucleotide positions 9027 and 9461. CONCLUSION: This study suggests that segregation as well as clonal expansion of mt-SNVs is specific to individual genomic loci, which is important foundational data in understanding of heteroplasmy and disease thresholds for mutation of pathogenic variants.
2024-06-24 | GSE218122 | GEO
Project description:Whole genome re-sequencing is still a costly method to detect genetic mutations that lead to altered forms of proteins and may be associated with disease development. Since the majority of disease-related single nucleotide variations (SNVs) are found in protein-coding regions, we propose to identify SNVs in expressed exons of the human genome using the recently developed RNA-Seq technique. We identify 12,176 and 10,621 SNVs, respectively, in Jurkat T cells and CD4+ T cells from a healthy donor. Interestingly, our data show that one copy of the TAL-1 protooncogene has a point mutation in 3’ UTR and only the mutant allele is expressed in Jurkat cells. We provide a comprehensive dataset for further understanding the cancer biology of Jurkat cells. Our results indicate that this is a cost-effective and efficient strategy to systematically identify SNVs in the expressed regions of the human genome. RNA-Seq experiments for two samples: CD4+ T cells from a healthy donor and Jurkat T cells. There are 8 lanes of data for each sample.
2009-06-15 | E-GEOD-16190 | biostudies-arrayexpress
Project description:Whole genome re-sequencing is still a costly method to detect genetic mutations that lead to altered forms of proteins and may be associated with disease development. Since the majority of disease-related single nucleotide variations (SNVs) are found in protein-coding regions, we propose to identify SNVs in expressed exons of the human genome using the recently developed RNA-Seq technique. We identify 12,176 and 10,621 SNVs, respectively, in Jurkat T cells and CD4+ T cells from a healthy donor. Interestingly, our data show that one copy of the TAL-1 protooncogene has a point mutation in 3’ UTR and only the mutant allele is expressed in Jurkat cells. We provide a comprehensive dataset for further understanding the cancer biology of Jurkat cells. Our results indicate that this is a cost-effective and efficient strategy to systematically identify SNVs in the expressed regions of the human genome.
2009-06-15 | GSE16190 | GEO
Project description:Germline BRCA2 loss-of function (LOF) variants identified by clinical genetic testing predispose to breast, ovarian, prostate and pancreatic cancer. However, variants of uncertain significance (VUS) (n>5000) limit the clinical use of testing results. Thus, there is an urgent need for functional characterization and clinical classification of all BRCA2 variants. Here we report on comprehensive saturation genome editing-based functional characterization of 99% of all possible single nucleotide variants (SNVs) in the BRCA2 DNA Binding Domain hotspot for pathogenic missense variants that is encoded by exons 15 to 26. The assay was based on deep sequence analysis of HAP1 haploid cells endogenously targeted using a CRISPR/cas9 knockin approach. A total of 6959 SNVs were characterized for effects on cell survival. The assay was validated relative to nonsense and synonymous variants, ClinVar pathogenic/likely pathogenic and benign/likely benign variants and homology directed repair cell based DNA repair assay results, all of which showed >94% sensitivity and specificity. Variants were assigned posterior probabilities of pathogenicity using a VarCall two component Bayesian mixture model and were further grouped according to ACMG strength of evidence under the PS3/BS3 rule resulting in Benign Strong (n=5430), Benign Moderate (n=190), Benign Supporting (n=61), VUS (122), Pathogenic Strong (n=1021), Pathogenic Moderate (n=88), and Pathogenic Supporting (n=47). Breast cancer case-control association studies showed that pooled SNVs encoding functionally pathogenic missense variants were associated with increased risks of breast (odds ratio (OR)3.81, 95%CI: 2.88-5.07) and ovarian cancer (OR 5.93, 95%CI: 4.12-8.52). The functional data were also combined with other sources of information in the ClinGen BRCA1/2 VCEP ACMG/AMP-classification model. A total of 785 SNVs, including 261 missense SNVs, were classified as pathogenic or likely pathogenic, while 5566 SNVs, including 3786 missense SNVs, were classified as benign or likely benign. These classified variants can now be used for risk assessment and clinical care of variant carriers.
2024-09-30 | GSE270424 | GEO
Project description:Single nucleotide variants (SNVs) in intronic regions have yet to be systematically investigated for their disease-causing potential. Using known pathogenic and neutral intronic SNVs (iSNVs) as training data, we develop the RegSNPs-intron algorithm based on a random forest classifier that integrates RNA splicing, protein structure and evolutionary conservation features. RegSNPs-intron shows excellent performance in evaluating the pathogenic impacts of iSNVs. Using a high-throughput functional reporter assay called ASSET-seq (ASsay for Splicing using ExonTrap and sequencing), we evaluate the impact of regSNPs-intron predictions on splicing outcome. Together, RegSNPs-intron and ASSET-seq enable effective prioritization of iSNVs for disease pathogenesis.
2019-09-30 | GSE138130 | GEO
Project description:Single nucleotide variants (SNVs) associated with cutaneous melanoma (CM) risk and prognosis
| PRJNA533122 | ENA
Project description:Many SNVs associated with human traits and genetic diseases are thought to alter the activity of existing regulatory elements. Some SNVs may also create entirely new regulatory elements which change gene expression, but the mechanism by which they do so is largely unknown. Here we show that a single base change in an otherwise unremarkable region of the human alpha-globin cluster creates an entirely new promoter and an associated unidirectional transcript. This SNV downregulates alpha-globin expression causing alpha-thalassaemia. Rather than competing for the activity of the enhancers, the new promoter lying between the α-globin genes and their associated super-enhancer acts as an orientation-dependent boundary element. Together these observations show how both the order and orientation of the fundamental elements of the genome determine patterns of gene expression and support the concept that promoters may act as boundary elements in mammals as in drosophila. Finally, these findings should prompt others to fully evaluate SNVs lying outside of known regulatory elements as causing changes in gene expression by creating new regulatory elements.
2021-03-25 | GSE159874 | GEO
Project description:Many SNVs associated with human traits and genetic diseases are thought to alter the activity of existing regulatory elements. Some SNVs may also create entirely new regulatory elements which change gene expression, but the mechanism by which they do so is largely unknown. Here we show that a single base change in an otherwise unremarkable region of the human alpha-globin cluster creates an entirely new promoter and an associated unidirectional transcript. This SNV downregulates alpha-globin expression causing alpha-thalassaemia. Rather than competing for the activity of the enhancers, the new promoter lying between the α-globin genes and their associated super-enhancer acts as an orientation-dependent boundary element. Together these observations show how both the order and orientation of the fundamental elements of the genome determine patterns of gene expression and support the concept that promoters may act as boundary elements in mammals as in drosophila. Finally, these findings should prompt others to fully evaluate SNVs lying outside of known regulatory elements as causing changes in gene expression by creating new regulatory elements.
2021-03-25 | GSE159873 | GEO