scholarly journals Replaying the evolutionary tape to investigate subgenome dominance in allopolyploid Brassica napus

2019 ◽  
Author(s):  
Kevin A. Bird ◽  
Chad Niederhuth ◽  
Shujun Ou ◽  
Malia Gehan ◽  
J. Chris Pires ◽  
...  
Keyword(s):  
Gene Expression ◽  
Brassica Napus ◽  
Gene Network ◽  
Phenotypic Diversity ◽  
Duplicate Genes ◽  
Network Analyses ◽  
Expression Bias ◽  
Plant Hybridization ◽  
Single Nucleus ◽  
Frequent Observation

AbstractInterspecific hybridization and allopolyploidization merges evolutionarily distinct parental genomes (subgenomes) into a single nucleus. A frequent observation is that one subgenome is “dominant” over the other subgenome, having a greater number of reatined duplicate genes and being more highly expressed. Which subgenome becomes dominantly expressed in allopolyploids remains poorly understood. Here we “replayed the evolutionary tape” with six isogenic resynthesized Brassica napus (rapeseed) allopolyploid lines and investigated subgenome dominance patterns over the first ten generations. We found that the same subgenome was consistently more dominantly expressed in all lines and generations. Furthermore, DNA methylation differences between subgenomes mirrored the observed gene expression bias towards the Brassica oleracea derived ‘C’ subgenome in all lines and generations. These differences in gene expression and methylation were also found when comparing the progenitor genomes, suggesting subgenome dominance is related to inherited parental genome differences rather than a byproduct of allopolyploidization. Gene network analyses indicated an enrichment for network interactions and several biological functions for ‘C’ subgenome biased pairs, but no enrichment was observed for ‘A’ subgenome biased pairs. These findings demonstrate that “replaying the evolutionary tape” in allopolyploids results in repeatable and predictable subgenome expression dominance patterns based on preexisting genetic differences among the parental species. These findings have major implications regarding the genotypic and phenotypic diversity observed following plant hybridization in both ecological and agricultural contexts.

scholarly journals Molecular pathology associated with altered synaptic transcriptome in the dorsolateral prefrontal cortex of depressed subjects

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuta Yoshino ◽  
Bhaskar Roy ◽  
Nilesh Kumar ◽  
M. Shahid Mukhtar ◽  
Yogesh Dwivedi
Keyword(s):  
Gene Expression ◽  
Cell Death ◽  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Gene Network ◽  
Nervous System Development ◽  
Network Analyses ◽  
Dorsolateral Prefrontal ◽  
Total Fraction ◽  
Transcriptomic Changes

AbstractDisrupted synaptic plasticity is the hallmark of major depressive disorder (MDD), with accompanying changes at the molecular and cellular levels. Often, the maladaptive molecular changes at the synapse are the result of global transcriptional reprogramming dictated by activity-dependent synaptic modulation. Thus far, no study has directly studied the transcriptome-wide expression changes locally at the synapse in MDD brain. Here, we have examined altered synaptic transcriptomics and their functional relevance in MDD with a focus on the dorsolateral prefrontal cortex (dlPFC). RNA was isolated from total fraction and purified synaptosomes of dlPFC from well-matched 15 non-psychiatric controls and 15 MDD subjects. Transcriptomic changes in synaptic and total fractions were detected by next-generation RNA-sequencing (NGS) and analyzed independently. The ratio of synaptic/total fraction was estimated to evaluate a shift in gene expression ratio in MDD subjects. Bioinformatics and network analyses were used to determine the biological relevance of transcriptomic changes in both total and synaptic fractions based on gene–gene network, gene ontology (GO), and pathway prediction algorithms. A total of 14,005 genes were detected in total fraction. A total of 104 genes were differentially regulated (73 upregulated and 31 downregulated) in MDD group based on 1.3-fold change threshold and p < 0.05 criteria. In synaptosomes, out of 13,236 detectable genes, 234 were upregulated and 60 were downregulated (>1.3-fold, p < 0.05). Several of these altered genes were validated independently by a quantitative polymerase chain reaction (qPCR). GO revealed an association with immune system processes and cell death. Moreover, a cluster of genes belonged to the nervous system development, and psychological disorders were discovered using gene–gene network analysis. The ratio of synaptic/total fraction showed a shift in expression of 119 genes in MDD subjects, which were primarily associated with neuroinflammation, interleukin signaling, and cell death. Our results suggest not only large-scale gene expression changes in synaptosomes, but also a shift in the expression of genes from total to synaptic fractions of dlPFC of MDD subjects with their potential role in immunomodulation and cell death. Our findings provide new insights into the understanding of transcriptomic regulation at the synapse and their possible role in MDD pathogenesis.

scholarly journals Gene Expression Differences Between Young Adults Based on Trauma History and Post-traumatic Stress Disorder

2021 ◽  
Vol 12 ◽  
Author(s):  
Kaitlin E. Bountress ◽  
Vladimir Vladimirov ◽  
Gowon McMichael ◽  
Z. Nathan Taylor ◽  
Gary Hardiman ◽  
...  
Keyword(s):  
Gene Expression ◽  
Post Traumatic Stress Disorder ◽  
Traumatic Stress ◽  
Gene Network ◽  
Stress Disorder ◽  
Trauma Exposure ◽  
Differentially Expressed ◽  
Post Traumatic Stress ◽  
Network Analyses ◽  
Post Traumatic

Background: The purpose of this study was to identify gene expression differences associated with post-traumatic stress disorder (PTSD) and trauma exposure (TE) in a three-group study design comprised of those with and without trauma exposure and PTSD.Methods: We conducted gene expression and gene network analyses in a sample (n = 45) composed of female subjects of European Ancestry (EA) with PTSD, TE without PTSD, and controls.Results: We identified 283 genes differentially expressed between PTSD-TE groups. In an independent sample of Veterans (n = 78) a small minority of these genes were also differentially expressed. We identified 7 gene network modules significantly associated with PTSD and TE (Bonferroni corrected p ≤ 0.05), which at a false discovery rate (FDR) of q ≤ 0.2, were significantly enriched for biological pathways involved in focal adhesion, neuroactive ligand receptor interaction, and immune related processes among others.Conclusions: This study uses gene network analyses to identify significant gene modules associated with PTSD, TE, and controls. On an individual gene level, we identified a large number of differentially expressed genes between PTSD-TE groups, a minority of which were also differentially expressed in the independent sample. We also demonstrate a lack of network module preservation between PTSD and TE, suggesting that the molecular signature of PTSD and trauma are likely independent of each other. Our results provide a basis for the identification of likely disease pathways and biomarkers involved in the etiology of PTSD.

scholarly journals Homoeolog expression bias and expression level dominance (ELD) in four tissues of natural allotetraploid Brassica napus

2020 ◽  
Author(s):  
Mengdi Li ◽  
Ruihua Wang ◽  
Xiaoming Wu ◽  
Jianbo Wang
Keyword(s):  
Gene Expression ◽  
Brassica Napus ◽  
Expression Patterns ◽  
Expression Level ◽  
Gene Expression Patterns ◽  
Homologous Gene ◽  
Gene Pairs ◽  
Expression Bias ◽  
Homoeolog Expression Bias ◽  
Expression Level Dominance

Abstract Background: Allopolyploidy is widespread in angiosperms, and they can coordinate two or more different genomes through genetic and epigenetic modifications to exhibit stronger vigor and adaptability. To explore the changes in homologous gene expression patterns in the natural allotetraploid Brassica napus (AnAnCnCn) relative to its two diploid progenitors, B. rapa (ArAr) and B. oleracea (CoCo), after approximately 7,500 years of domestication, the global gene pair expression patterns in four major tissues (stems, leaves, flowers and siliques) of these three species were analyzed using an RNA sequencing approach. Results: The results showed that the ‘transcriptomic shock’ phenomenon was alleviated in natural B. napus after approximately 7,500 years of natural domestication, and most differentially expressed genes (DEGs) in B. napus were downregulated relative to those in its two diploid progenitors. The KEGG analysis indicated that three pathways related to photosynthesis were enriched in both comparison groups (AnAnCnCn vs ArAr and AnAnCnCn vs CoCo), and these pathways were all downregulated in four tissues of B. napus. In addition, homoeolog expression bias and expression level dominance (ELD) in B. napus were thoroughly studied through analysis of expression levels of 27609 B. rapa-B. oleracea orthologous gene pairs. The overwhelming majority of gene pairs (an average of 86.7%) in B. napus maintained their expression pattern in two diploid progenitors, and approximately 78.1% of the gene pairs showed expression bias with a preference toward the A subgenome. Overall, an average of 48%, 29.7% and 22.3% homologous gene pairs exhibited additive expression, ELD and transgressive expression in B. napus, respectively. The ELD bias varies from tissue to tissue; specifically, more gene pairs in stems and siliques showed ELD-A, whereas the opposite was observed in leaves and flowers. More transgressive upregulation, rather than downregulation, was observed in gene pairs of B. napus. Conclusions: In general, these results may provide a comprehensive understanding of the changes in homologous gene expression patterns in natural B. napus after approximately 7,500 years of evolution and domestication and may enhance our understanding of allopolyploidy.

scholarly journals Homoeolog expression bias and expression level dominance (ELD) in four tissues of natural allotetraploid Brassica napus

2020 ◽  
Author(s):  
Mengdi Li ◽  
Ruihua Wang ◽  
Xiaoming Wu ◽  
Jianbo Wang
Keyword(s):  
Gene Expression ◽  
Brassica Napus ◽  
Expression Patterns ◽  
Expression Level ◽  
Gene Expression Patterns ◽  
Homologous Gene ◽  
Gene Pairs ◽  
Expression Bias ◽  
Homoeolog Expression Bias ◽  
Expression Level Dominance

Abstract Background: Allopolyploidy is widespread in angiosperms, and they can coordinate two or more different genomes through genetic and epigenetic modifications to exhibit stronger vigor and adaptability. To explore the changes in homologous gene expression patterns in the natural allotetraploid Brassica napus (AnAnCnCn) relative to its two diploid progenitors, B. rapa (ArAr) and B. oleracea (CoCo), after approximately 7,500 years of domestication, the global gene pair expression patterns in four major tissues (stems, leaves, flowers and siliques) of these three species were analyzed using an RNA sequencing approach. Results: The results showed that the ‘transcriptomic shock’ phenomenon was alleviated in natural B. napus after approximately 7,500 years of natural domestication, and most differentially expressed genes (DEGs) in B. napus were downregulated relative to those in its two diploid progenitors. The KEGG analysis indicated that three pathways related to photosynthesis were enriched in both comparison groups (AnAnCnCn vs ArAr and AnAnCnCn vs CoCo), and these pathways were all downregulated in four tissues of B. napus. In addition, homoeolog expression bias and expression level dominance (ELD) in B. napus were thoroughly studied through analysis of expression levels of 27609 B. rapa-B. oleracea orthologous gene pairs. The overwhelming majority of gene pairs (an average of 86.7%) in B. napus maintained their expression pattern in two diploid progenitors, and approximately 78.1% of the gene pairs showed expression bias with a preference toward the A subgenome. Overall, an average of 48%, 29.7% and 22.3% homologous gene pairs exhibited additive expression, ELD and transgressive expression in B. napus, respectively. The ELD bias varies from tissue to tissue; specifically, more gene pairs in stems and siliques showed ELD-A, whereas the opposite was observed in leaves and flowers. More transgressive upregulation, rather than downregulation, was observed in gene pairs of B. napus. Conclusions: In general, these results may provide a comprehensive understanding of the changes in homologous gene expression patterns in natural B. napus after approximately 7,500 years of evolution and domestication and may enhance our understanding of allopolyploidy.

scholarly journals Homoeolog expression bias and expression level dominance (ELD) in four tissues of natural allotetraploid Brassica napus

2020 ◽  
Author(s):  
Mengdi Li ◽  
Ruihua Wang ◽  
Xiaoming Wu ◽  
Jianbo Wang
Keyword(s):  
Gene Expression ◽  
Brassica Napus ◽  
Expression Patterns ◽  
Expression Level ◽  
Gene Expression Patterns ◽  
Homologous Gene ◽  
Gene Pairs ◽  
Expression Bias ◽  
Homoeolog Expression Bias ◽  
Expression Level Dominance

Abstract Background: Allopolyploidy is widespread in angiosperms, and they can coordinate two or more different genomes through genetic and epigenetic modifications to exhibit stronger vigor and adaptability. To explore the changes in homologous gene expression patterns in the natural allotetraploid Brassica napus (AnAnCnCn) relative to its two diploid progenitors, B. rapa (ArAr) and B. oleracea (CoCo), after approximately 7,500 years of domestication, the global gene pair expression patterns in four major tissues (stems, leaves, flowers and siliques) of these three species were analyzed using an RNA sequencing approach.Results: The results showed that the ‘transcriptomic shock’ phenomenon was alleviated in natural B. napus after approximately 7,500 years of natural domestication, and most differentially expressed genes (DEGs) in B. napus were downregulated relative to those in its two diploid progenitors. The KEGG analysis indicated that three pathways related to photosynthesis were enriched in both comparison groups (AnAnCnCn vs ArAr and AnAnCnCn vs CoCo), and these pathways were all downregulated in four tissues of B. napus. In addition, homoeolog expression bias and expression level dominance (ELD) in B. napus were thoroughly studied through analysis of expression levels of 27609 B. rapa-B. oleracea orthologous gene pairs. The overwhelming majority of gene pairs (an average of 86.7%) in B. napus maintained their expression pattern in two diploid progenitors, and approximately 78.1% of the gene pairs showed expression bias with a preference toward the A subgenome. Overall, an average of 48%, 29.7% and 22.3% homologous gene pairs exhibited additive expression, ELD and transgressive expression in B. napus, respectively. The ELD bias varies from tissue to tissue; specifically, more gene pairs in stems and siliques showed ELD-A, whereas the opposite was observed in leaves and flowers. More transgressive upregulation, rather than downregulation, was observed in gene pairs of B. napus.Conclusions: In general, these results may provide a comprehensive understanding of the changes in homologous gene expression patterns in natural B. napus after approximately 7,500 years of evolution and domestication and may enhance our understanding of allopolyploidy.

scholarly journals Advancing the understanding of the embryo transcriptome co-regulation using meta-, functional, and gene network analysis tools

Reproduction ◽  
2008 ◽  
Vol 135 (2) ◽  
pp. 213-224 ◽  
Author(s):  
S L Rodriguez-Zas ◽  
Y Ko ◽  
H A Adams ◽  
B R Southey
Keyword(s):  
Gene Expression ◽  
Gene Networks ◽  
Gene Network ◽  
Meta Analysis ◽  
Expression Patterns ◽  
Cell Communication ◽  
Adherens Junction ◽  
Differentially Expressed ◽  
Network Analyses ◽  
Wide Range

Embryo development is a complex process orchestrated by hundreds of genes and influenced by multiple environmental factors. We demonstrate the application of simple and effective meta-study and gene network analyses strategies to characterize the co-regulation of the embryo transcriptome in a systems biology framework. A meta-analysis of nine microarray experiments aimed at characterizing the effect of agents potentially harmful to mouse embryos improved the ability to accurately characterize gene co-expression patterns compared with traditional within-study approaches. Simple overlap of significant gene lists may result in under-identification of genes differentially expressed. Sample-level meta-analysis techniques are recommended when common treatment levels or samples are present in more than one study. Otherwise, study-level meta-analysis of standardized estimates provided information on the significance and direction of the differential expression. Cell communication pathways were highly represented among the genes differentially expressed across studies. Mixture and dependence Bayesian network approaches were able to reconstruct embryo-specific interactions among genes in the adherens junction, axon guidance, and actin cytoskeleton pathways. Gene networks inferred by both approaches were mostly consistent with minor differences due to the complementary nature of the methodologies. The top–down approach used to characterize gene networks can offer insights into the mechanisms by which the conditions studied influence gene expression. Our work illustrates that further examination of gene expression information from microarray studies including meta- and gene network analyses can help characterize transcript co-regulation and identify biomarkers for the reproductive and embryonic processes under a wide range of conditions.

scholarly journals Homoeolog expression bias and expression level dominance (ELD) in four tissues of natural allotetraploid Brassica napus

2019 ◽  
Author(s):  
Mengdi Li ◽  
Ruihua Wang ◽  
Xiaoming Wu ◽  
Jianbo Wang
Keyword(s):  
Gene Expression ◽  
Brassica Napus ◽  
Expression Pattern ◽  
Expression Patterns ◽  
Expression Level ◽  
Homologous Gene ◽  
Gene Pairs ◽  
Expression Bias ◽  
Homoeolog Expression Bias ◽  
Expression Level Dominance

Abstract Background Allopolyploids were widespread in angiosperms, and they can coordinate two or more different genomes through genetic and epigenetic modification so as to show stronger growth vigor and adaptability. To explore the changes of homologous gene expression pattern in the natural allotetraploid Brassica napus (AnAnCnCn) relative to its two diploid progenitors, B. rapa (ArAr) and B. oleracea (CoCo), after about 7,500 years of domestication, the global gene pair expression patterns in four major tissues (stems, leaves, flowers and siliques) of these three species were analyzed using RNA sequencing approach. Results Results showed that the ‘transcriptomic shock’ phenomenon was alleviated in natural B. napus after about 7500 years of natural domestication, and most differentially expressed genes (DEGs) in B. napus were down-regulated relative to those in its two diploid progenitors. The KEGG analysis indicated that three pathways related to photosynthesis were enriched in both two comparison groups (AnAnCnCn vs ArAr and AnAnCnCn vs CoCo) and these pathways were all down-regulated in four tissues of B. napus. In addition, the homoeolog expression bias and expression level dominance (ELD) in B. napus were thoroughly studied through analysis the expression levels of 27609 B. rapa-B. oleracea orthologous gene pairs. The overwhelming majority of gene pairs (an average of 86.7%) in B. napus maintained their expression pattern in two diploid progenitors, and approximately 78.1% of the gene pairs showed expression bias with a preference toward the A subgenome. Overall, an average of 48%, 29.7% and 22.3% homologous gene pairs exhibited additivity expression, ELD and transgressive expression in B. napus, respectively. The ELD bias varies from tissue to tissue, specifically, more gene pairs in stems and siliques showed ELD-A, whereas the opposite was true in leaves and flowers. More transgressive up-regulation expression gene pairs were found in B. napus. Conclusions In general, these results can provide a comprehensive understanding of the changes of homologous gene expression patterns in natural B. napus after about 7,500 years of evolution and domestication, and enhance our understanding of allopolyploids.

scholarly journals Integrative genomics reveals paths to sex dimorphism in Salix purpurea L

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Brennan Hyden ◽  
Craig H. Carlson ◽  
Fred E. Gouker ◽  
Jeremy Schmutz ◽  
Kerrie Barry ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sex Determination ◽  
Bisulfite Sequencing ◽  
Epigenetic Modification ◽  
Small Rna Sequencing ◽  
Regulation Of Transcription ◽  
Eqtl Analysis ◽  
Sex Dimorphism ◽  
Network Analyses ◽  
Salix Purpurea

AbstractSex dimorphism and gene expression were studied in developing catkins in 159 F2 individuals from the bioenergy crop Salix purpurea, and potential mechanisms and pathways for regulating sex development were explored. Differential expression, eQTL, bisulfite sequencing, and network analysis were used to characterize sex dimorphism, detect candidate master regulator genes, and identify pathways through which the sex determination region (SDR) may mediate sex dimorphism. Eleven genes are presented as candidates for master regulators of sex, supported by gene expression and network analyses. These include genes putatively involved in hormone signaling, epigenetic modification, and regulation of transcription. eQTL analysis revealed a suite of transcription factors and genes involved in secondary metabolism and floral development that were predicted to be under direct control of the sex determination region. Furthermore, data from bisulfite sequencing and small RNA sequencing revealed strong differences in expression between males and females that would implicate both of these processes in sex dimorphism pathways. These data indicate that the mechanism of sex determination in Salix purpurea is likely different from that observed in the related genus Populus. This further demonstrates the dynamic nature of SDRs in plants, which involves a multitude of mechanisms of sex determination and a high rate of turnover.

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