This SuperSeries is composed of the SubSeries listed below.
Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression patterns in the F1 hybrid.
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View SamplesMicroarray analysis of gene expression patterns in immature ear, seedling, and embryo tissues from the maize inbred lines B73 and Mo17 identified numerous genes with variable expression. Some genes had detectable expression in only one of the two inbreds; most of these genes were detected in the genomic DNA of both inbreds, indicating that the expression differences are likely caused by differential regulation rather than by differences in gene content. Gene expression was also monitored in the reciprocal F1 hybrids B73xMo17 and Mo17xB73. The reciprocal F1 hybrid lines did not display parental effects on gene expression levels. Approximately 80% of the differentially expressed genes displayed additive expression patterns in the hybrids relative to the inbred parents. The approximately 20% of genes that display nonadditive expression patterns tend to be expressed at levels within the parental range, with minimal evidence for novel expression levels greater than the high parent or less than the low parent. Analysis of allele-specific expression patterns in the hybrid suggested that intraspecific variation in gene expression levels is largely attributable to cis-regulatory variation in maize. Collectively, our data suggest that allelic cis-regulatory variation between B73 and Mo17 dictates maintenance of inbred allelic expression levels in the F1 hybrid, resulting in additive expression patterns.
Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression patterns in the F1 hybrid.
No sample metadata fields
View SamplesMicroarray analysis of gene expression patterns in immature ear, seedling, and embryo tissues from the maize inbred lines B73 and Mo17 identified numerous genes with variable expression. Some genes had detectable expression in only one of the two inbreds; most of these genes were detected in the genomic DNA of both inbreds, indicating that the expression differences are likely caused by differential regulation rather than by differences in gene content. Gene expression was also monitored in the reciprocal F1 hybrids B73xMo17 and Mo17xB73. The reciprocal F1 hybrid lines did not display parental effects on gene expression levels. Approximately 80% of the differentially expressed genes displayed additive expression patterns in the hybrids relative to the inbred parents. The approximately 20% of genes that display nonadditive expression patterns tend to be expressed at levels within the parental range, with minimal evidence for novel expression levels greater than the high parent or less than the low parent. Analysis of allele-specific expression patterns in the hybrid suggested that intraspecific variation in gene expression levels is largely attributable to cis-regulatory variation in maize. Collectively, our data suggest that allelic cis-regulatory variation between B73 and Mo17 dictates maintenance of inbred allelic expression levels in the F1 hybrid, resulting in additive expression patterns.
Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression patterns in the F1 hybrid.
No sample metadata fields
View SamplesMicroarray analysis of gene expression patterns in immature ear, seedling, and embryo tissues from the maize inbred lines B73 and Mo17 identified numerous genes with variable expression. Some genes had detectable expression in only one of the two inbreds; most of these genes were detected in the genomic DNA of both inbreds, indicating that the expression differences are likely caused by differential regulation rather than by differences in gene content. Gene expression was also monitored in the reciprocal F1 hybrids B73xMo17 and Mo17xB73. The reciprocal F1 hybrid lines did not display parental effects on gene expression levels. Approximately 80% of the differentially expressed genes displayed additive expression patterns in the hybrids relative to the inbred parents. The approximately 20% of genes that display nonadditive expression patterns tend to be expressed at levels within the parental range, with minimal evidence for novel expression levels greater than the high parent or less than the low parent. Analysis of allele-specific expression patterns in the hybrid suggested that intraspecific variation in gene expression levels is largely attributable to cis-regulatory variation in maize. Collectively, our data suggest that allelic cis-regulatory variation between B73 and Mo17 dictates maintenance of inbred allelic expression levels in the F1 hybrid, resulting in additive expression patterns.
Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression patterns in the F1 hybrid.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Nonadditive expression and parent-of-origin effects identified by microarray and allele-specific expression profiling of maize endosperm.
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View SamplesThe nuclear content of the plant endosperm is the result of the contribution two maternal genomes and a single paternal genome. This 2:1 dosage relationship provides a unique system for studying the additivity of gene expression levels in reciprocal hybrids. A combination of microarray profiling and allele-specific expression analysis was performed using RNA isolated from endosperm tissues of maize inbred lines B73 and Mo17 and their reciprocal hybrids at two developmental stages, 13 and 19 days after pollination. By assessing the relative levels of expression in the reciprocal hybrids it was possible to determine the prevalence of additive and non-additive expression patterns. While the majority of differentially expressed genes displayed additive expression patterns in the endosperm, approximately 10% of the genes displayed non-additive expression patterns including maternal-like, paternal-like, dominant high-parent, dominant low-parent and expression patterns outside the range of the inbreds. The frequency of hybrid expression patterns outside of the parental range in maize endosperm tissue is much higher than that observed for vegetative tissues. For a set of 90 genes allele-specific expression assays were employed to monitor allelic bias and regulatory variation. Eight of these genes exhibited evidence for maternally or paternally biased expression at multiple stages of endosperm development and are potential examples of differential imprinting. Collectively, our data indicate that parental effects on gene expression are much stronger in endosperm than in vegetative tissues, and that endosperm imprinting may be far more common than previously estimated.
Nonadditive expression and parent-of-origin effects identified by microarray and allele-specific expression profiling of maize endosperm.
No sample metadata fields
View SamplesThe nuclear content of the plant endosperm is the result of the contribution two maternal genomes and a single paternal genome. This 2:1 dosage relationship provides a unique system for studying the additivity of gene expression levels in reciprocal hybrids. A combination of microarray profiling and allele-specific expression analysis was performed using RNA isolated from endosperm tissues of maize inbred lines B73 and Mo17 and their reciprocal hybrids at two developmental stages, 13 and 19 days after pollination. By assessing the relative levels of expression in the reciprocal hybrids it was possible to determine the prevalence of additive and non-additive expression patterns. While the majority of differentially expressed genes displayed additive expression patterns in the endosperm, approximately 10% of the genes displayed non-additive expression patterns including maternal-like, paternal-like, dominant high-parent, dominant low-parent and expression patterns outside the range of the inbreds. The frequency of hybrid expression patterns outside of the parental range in maize endosperm tissue is much higher than that observed for vegetative tissues. For a set of 90 genes allele-specific expression assays were employed to monitor allelic bias and regulatory variation. Eight of these genes exhibited evidence for maternally or paternally biased expression at multiple stages of endosperm development and are potential examples of differential imprinting. Collectively, our data indicate that parental effects on gene expression are much stronger in endosperm than in vegetative tissues, and that endosperm imprinting may be far more common than previously estimated.
Nonadditive expression and parent-of-origin effects identified by microarray and allele-specific expression profiling of maize endosperm.
No sample metadata fields
View SamplesABSTRACT: BACKGROUND: While changes in chromosome number that result in aneuploidy are associated with phenotypic consequences such as Down syndrome and cancer, the molecular causes of specific phenotypes and genome-wide expression changes that occur in aneuploids are still being elucidated. RESULTS: We employed a segmental aneuploid condition in maize to study phenotypic and gene expression changes associated with aneuploidy. Maize plants that are trisomic for 90% of the short arm of chromosome 5 and monosomic for a small distal portion of the short arm of chromosome 6 exhibited a phenotypic syndrome that includes reduced stature, tassel morphology changes and the presence of knots on the leaves. The knotted-like homeobox gene knox10, which is located on the short arm of chromosome 5, was shown to be ectopically expressed in developing leaves of the aneuploid plants. Expression profiling revealed that ~40% of the expressed genes in the trisomic region exhibited the expected 1.5 fold increased transcript levels while the remaining 60% of genes did not show altered expression even with increased gene dosage. CONCLUSIONS: We found that the majority of genes with altered expression levels were located within the chromosomal regions affected by the segmental aneuploidy and exhibits dosage-dependent expression changes. A small number of genes exhibit higher levels of expression change not predicted by the dosage, or display altered expression even though they are not located in the aneuploid regions.
Profiling expression changes caused by a segmental aneuploid in maize.
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View SamplesLong non-coding RNAs (lncRNAs) contribute to (patho)physiological processes in the heart. Aging is the major risk factor for cardiovascular disease and cardiomyocyte apoptosis is an underlying cause for age-related cardiac dysfunction. RNA sequencing of cardiomyocytes from young and aged mouse hearts revealed several aging-regulated lncRNAs. An siRNA screen for caspase activity identified the aging-regulated lncRNA Sarrah (ENSMUST00000140003) as anti-apoptotic, which we confirmed in human cells (human SARRAH is annotated as OXCT1-AS1). Importantly, human engineered heart tissue showed impaired contractile force development upon SARRAH knockdown compared with controls. Computational prediction of RNA-DNA triple helix formation showed that SARRAH may directly bind the promoters of genes downregulated after SARRAH silencing, which mainly consist of cell survival genes. Indeed, nuclear magnetic resonance spectroscopy confirmed RNA-DNA triple helix formation and cardiomyocytes lacking the triple helix-forming domain of Sarrah showed an increase in apoptosis. One of the key direct SARRAH targets is NRF2, an anti-oxidant transcription factor. Restoration of NRF2 levels after SARRAH silencing partially rescues the reduction in cell viability. RNA affinity purification mass spectrometry analysis identified CRIP2 as main protein interaction partner. Furthermore, SARRAH associates with acetyltransferase p300 and acetylated histone H3K27. Finally, Sarrah was also profoundly downregulated after acute myocardial infarction (AMI) in mice. Adeno-associated virus-mediated overexpression of Sarrah in mice showed better recovery of cardiac contractile function after AMI compared to control mice, as measured by echocardiography and magnetic resonance imaging, consistent with a decrease in cardiomyocyte cell death and an increase in endothelial cell proliferation. In summary, we identified the anti-apoptotic evolutionary conserved lncRNA Sarrah, which is downregulated by aging, as a pivotal regulator of cardiomyocyte survival. Sarrah overexpression has beneficial effects on AMI recovery highlighting it as a potential therapeutic approach against heart failure.
Aging-regulated anti-apoptotic long non-coding RNA Sarrah augments recovery from acute myocardial infarction.
Specimen part
View SamplesExpression profiling analyses for 5 maize inbreds and 4 hybrids, chosen to represent diversity in genotypes and heterosis responses, revealed a correlation between genetic diversity and transcriptional variation. The majority of differentially expressed genes in each of the different hybrids exhibited additive expression patterns, and ~25% exhibited statistically significant non-additive expression profiles. Among the non-additive profiles, ~80% exhibited hybrid expression levels between the parental levels, ~20% exhibited hybrid expression levels at the parental levels and ~1% exhibited hybrid levels outside the parental range. These findings indicate that the frequencies of additive and non-additive expression patterns are very similar across a range of hybrid lines.
Gene expression analyses in maize inbreds and hybrids with varying levels of heterosis.
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