scholarly journals The role of genomic vs. epigenomic variation in shaping patterns of convergent transcriptomic variation across continents in a young species complex

2019 ◽  
Author(s):  
Clément Rougeux ◽  
Martin Laporte ◽  
Pierre-Alexandre Gagnaire ◽  
Louis Bernatchez
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Adaptive Divergence ◽  
Relative Role ◽  
Gene Expression Variation ◽  
Genomic Changes ◽  
Expression Variation ◽  
Relative Contribution ◽  
Variation Explained

ABSTRACTRepeated adaptive divergence in replicates of phenotypic diversification offers a propitious context to identify the molecular bases associated to adaptive divergence. A currently hotly debated topic pertains to the relative role of genomic vs. epigenomic variation in shaping patterns of phenotypic variation at the gene expression level. Here, we combined genomic, epigenomic and transcriptomic information from 64 individuals in order to quantify the relative role of SNPs and DNA methylation variation in the repeated evolution of four limnetic-benthic whitefish species pairs from Europe and North America. We first found evidence for 149 convergent differentially methylated regions (DMRs) between species across continents, which significantly influenced levels of gene expression. Hyper-methylated DMRs in the limnetic species were globally associated to an expression repression relatively to benthic species, and inversely. Furthermore, we identified 108 convergent genetic variants (eQTLs) associated to gene expression differences between species. Gene expression differences were more pronounced in genes harbouring eQTL compared to those associated with DMRs, thus revealing a greater effect of eQTLs on gene expression. Multivariate analyses allowed partitioning the relative contribution of epi-/genomic changes and their association to gene expression variation. Most of the gene expression variation was significantly explained by genomic (4.1%) and putatively genomic-epigenomic interactive variation (46.7%), while “pure” epigenomic variation explained marginally 2.3% of the gene expression variation across continents. This study provides a rare qualitative and quantitative documentation of the relative role of genomic, DNA methylation and their interaction in shaping patterns of convergent gene expression during the process of ecological speciation.

scholarly journals DNA methylation patterns associate with genetic and gene expression variation in HapMap cell lines

2011 ◽  
Vol 12 (1) ◽  
Author(s):  
Jordana T Bell ◽  
Athma A Pai ◽  
Joseph K Pickrell ◽  
Daniel J Gaffney ◽  
Roger Pique-Regi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Cell Lines ◽  
Gene Expression Variation ◽  
Expression Variation ◽  
Methylation Patterns

scholarly journals Correction: DNA methylation patterns associate with genetic and gene expression variation in HapMap cell lines

2011 ◽  
Vol 12 (6) ◽  
pp. 405 ◽  
Author(s):  
Jordana T Bell ◽  
Athma A Pai ◽  
Joseph K Pickrell ◽  
Daniel J Gaffney ◽  
Roger Pique-Regi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Cell Lines ◽  
Gene Expression Variation ◽  
Expression Variation ◽  
Methylation Patterns

scholarly journals Regulatory architecture of gene expression variation in the threespine stickleback, Gasterosteus aculeatus

2016 ◽  
Author(s):  
Victoria L. Pritchard ◽  
Heidi M. Viitaniemi ◽  
R.J. Scott McCairns ◽  
Juha Merilä ◽  
Mikko Nikinmaa ◽  
...  
Keyword(s):  
Gene Expression ◽  
Regulatory Networks ◽  
Gasterosteus Aculeatus ◽  
Genotyping By Sequencing ◽  
Interval Mapping ◽  
Threespine Stickleback ◽  
Adaptive Divergence ◽  
Gene Expression Variation ◽  
Expression Variation ◽  
Regulatory Architecture

Much adaptive evolutionary change is underlain by mutational variation in regions of the genome that regulate gene expression rather than in the coding regions of the genes themselves. An understanding of the role of gene expression variation in facilitating local adaptation will be aided by an understanding of underlying regulatory networks. Here, we characterize the genetic architecture of gene expression variation in the threespine stickleback (Gasterosteus aculeatus), an important model in the study of adaptive evolution. We collected transcriptomic and genomic data from 60 half-sib families using an expression microarray and genotyping-by-sequencing, and located QTL underlying the variation in gene expression (eQTL) in liver tissue using an interval mapping approach. We identified eQTL for several thousand expression traits. Expression was influenced by polymorphism in both cis and trans regulatory regions. Trans eQTL clustered into hotspots. We did not identify master transcriptional regulators in hotspot locations: rather, the presence of hotspots may be driven by complex interactions between multiple transcription factors. One observed hotspot co-located with a QTL recently found to underlie salinity tolerance in the threespine stickleback. However, most other observed hotspots did not co-locate with regions of the genome known to be involved in adaptive divergence between marine and freshwater habitats.

scholarly journals Massively parallel gene expression variation measurement of a synonymous codon library

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Alexander Schmitz ◽  
Fuzhong Zhang
Keyword(s):  
Gene Expression ◽  
Codon Usage ◽  
Single Cells ◽  
Massively Parallel ◽  
Protein Abundance ◽  
Translation Efficiency ◽  
Gene Expression Variation ◽  
Expression Variation ◽  
Change In Mean ◽  
Adaptation Index

Abstract Background Cell-to-cell variation in gene expression strongly affects population behavior and is key to multiple biological processes. While codon usage is known to affect ensemble gene expression, how codon usage influences variation in gene expression between single cells is not well understood. Results Here, we used a Sort-seq based massively parallel strategy to quantify gene expression variation from a green fluorescent protein (GFP) library containing synonymous codons in Escherichia coli. We found that sequences containing codons with higher tRNA Adaptation Index (TAI) scores, and higher codon adaptation index (CAI) scores, have higher GFP variance. This trend is not observed for codons with high Normalized Translation Efficiency Index (nTE) scores nor from the free energy of folding of the mRNA secondary structure. GFP noise, or squared coefficient of variance (CV2), scales with mean protein abundance for low-abundant proteins but does not change at high mean protein abundance. Conclusions Our results suggest that the main source of noise for high-abundance proteins is likely not originating at translation elongation. Additionally, the drastic change in mean protein abundance with small changes in protein noise seen from our library implies that codon optimization can be performed without concerning gene expression noise for biotechnology applications.

scholarly journals Stress Modifies the Expression of Glucocorticoid-Responsive Genes by Acting at Epigenetic Levels in the Rat Prefrontal Cortex: Modulatory Activity of Lurasidone

2021 ◽  
Vol 22 (12) ◽  
pp. 6197
Author(s):  
Paola Brivio ◽  
Giulia Sbrini ◽  
Letizia Tarantini ◽  
Chiara Parravicini ◽  
Piotr Gruca ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Chronic Stress ◽  
Chronic Mild Stress ◽  
Male Rats ◽  
Mild Stress ◽  
Experimental Conditions ◽  
Glucocorticoid Responsive Element ◽  
Responsive Element

Epigenetics is one of the mechanisms by which environmental factors can alter brain function and may contribute to central nervous system disorders. Alterations of DNA methylation and miRNA expression can induce long-lasting changes in neurobiological processes. Hence, we investigated the effect of chronic stress, by employing the chronic mild stress (CMS) and the chronic restraint stress protocol, in adult male rats, on the glucocorticoid receptor (GR) function. We focused on DNA methylation specifically in the proximity of the glucocorticoid responsive element (GRE) of the GR responsive genes Gadd45β, Sgk1, and Gilz and on selected miRNA targeting these genes. Moreover, we assessed the role of the antipsychotic lurasidone in modulating these alterations. Chronic stress downregulated Gadd45β and Gilz gene expression and lurasidone normalized the Gadd45β modification. At the epigenetic level, CMS induced hypermethylation of the GRE of Gadd45β gene, an effect prevented by lurasidone treatment. These stress-induced alterations were still present even after a period of rest from stress, indicating the enduring nature of such changes. However, the contribution of miRNA to the alterations in gene expression was moderate in our experimental conditions. Our results demonstrated that chronic stress mainly affects Gadd45β expression and methylation, effects that are prolonged over time, suggesting that stress leads to changes in DNA methylation that last also after the cessation of stress procedure, and that lurasidone is a modifier of such mechanisms.

scholarly journals Gene expression variation increase in trisomy 21 tissues

2008 ◽  
Vol 19 (6) ◽  
pp. 398-405 ◽  
Author(s):  
Ching Yu Chou ◽  
Li Yu Liu ◽  
Chien Yu Chen ◽  
Cheng Hsien Tsai ◽  
Hsiao Lin Hwa ◽  
...  
Keyword(s):  
Gene Expression ◽  
Trisomy 21 ◽  
Gene Expression Variation ◽  
Expression Variation

DDR1 methylation is associated with bipolar disorder and the isoform expression and methylation of myelin genes

Epigenomics ◽  
2021 ◽  
Author(s):  
Beatriz Garcia-Ruiz ◽  
Manuel Castro de Moura ◽  
Gerard Muntané ◽  
Lourdes Martorell ◽  
Elena Bosch ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Bipolar Disorder ◽  
Mrna Expression ◽  
Gene Expression Analysis ◽  
Mrna Levels ◽  
Healthy Controls ◽  
Genome Wide ◽  
Isoform Expression

Aim: To investigate DDR1 methylation in the brains of bipolar disorder (BD) patients and its association with DDR1 mRNA levels and comethylation with myelin genes. Materials & methods: Genome-wide profiling of DNA methylation (Infinium MethylationEPIC BeadChip) corrected for glial composition and DDR1 gene expression analysis in the occipital cortices of individuals with BD (n = 15) and healthy controls (n = 15) were conducted. Results: DDR1 5-methylcytosine levels were increased and directly associated with DDR1b mRNA expression in the brains of BD patients. We also observed that DDR1 was comethylated with a group of myelin genes. Conclusion: DDR1 is hypermethylated in BD brain tissue and is associated with isoform expression. Additionally, DDR1 comethylation with myelin genes supports the role of this receptor in myelination.

Retrovirus-induced interference with collagen I gene expression in Mov13 fibroblasts is maintained in the absence of DNA methylation

1991 ◽  
Vol 11 (1) ◽  
pp. 47-54
Author(s):  
H Chan ◽  
S Hartung ◽  
M Breindl
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Chromatin Structure ◽  
Transcriptional Activity ◽  
Xenopus Laevis Oocytes ◽  
Regulatory Sequences ◽  
Type I ◽  
Wild Type ◽  
Col1a1 Gene

We have studied the role of DNA methylation in repression of the murine alpha 1 type I collagen (COL1A1) gene in Mov13 fibroblasts. In Mov13 mice, a retroviral provirus has inserted into the first intron of the COL1A1 gene and blocks its expression at the level of transcriptional initiation. We found that regulatory sequences in the COL1A1 promoter region that are involved in the tissue-specific regulation of the gene are unmethylated in collagen-expressing wild-type fibroblasts and methylated in Mov13 fibroblasts, confirming and extending earlier observations. To directly assess the role of DNA methylation in the repression of COL1A1 gene transcription, we treated Mov13 fibroblasts with the demethylating agent 5-azacytidine. This treatment resulted in a demethylation of the COL1A1 regulatory sequences but failed to activate transcription of the COL1A1 gene. Moreover, the 5-azacytidine treatment induced a transcription-competent chromatin structure in the retroviral sequences but not in the COL1A1 promoter. In DNA transfection and microinjection experiments, we found that the provirus interfered with transcriptional activity of the COL1A1 promoter in Mov13 fibroblasts but not in Xenopus laevis oocytes. In contrast, the wild-type COL1A1 promoter was transcriptionally active in Mov13 fibroblasts. These experiments showed that the COL1A1 promoter is potentially transcriptionally active in the presence of proviral sequences and that Mov13 fibroblasts contain the trans-acting factors required for efficient COL1A1 gene expression. Our results indicate that the provirus insertion in Mov13 can inactivate COL1A1 gene expression at several levels. It prevents the developmentally regulated establishment of a transcription-competent methylation pattern and chromatin structure of the COL1A1 domain and, in the absence of DNA methylation, appears to suppress the COL1A1 promoter in a cell-specific manner, presumably by assuming a dominant chromatin structure that may be incompatible with transcriptional activity of flanking cellular sequences.

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