Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression - Immature ear data
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ABSTRACT:
ORGANISM(S): Zea mays
PROVIDER: GSE8176 | GEO | 2007/06/21
SECONDARY ACCESSION(S): PRJNA105419
REPOSITORIES: GEO
Similar Datasets
Project description:Microarray 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. Keywords: genotype comparison
2007-06-21 | GSE8179 | GEO
Project description:Microarray 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. Keywords: genotype comparison
2007-06-21 | GSE8174 | GEO
Project description:Microarray 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. Experiment Overall Design: Affymetrix expression profiling was used to study gene expression in 19 day after pollination embryo tissue of maize. Three biological replicates were performed for four different genotypes; B73, Mo17, B73xMo17 and Mo17xB73.
2008-06-16 | E-GEOD-8179 | biostudies-arrayexpress
Project description:Microarray 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. Experiment Overall Design: Affymetrix expression profiling was used to study gene expression in aerial tissue from 11-day seedlings of maize. Three biological replicates were performed for four different genotypes; B73, Mo17, B73xMo17 and Mo17xB73.
2008-06-17 | E-GEOD-8174 | biostudies-arrayexpress
Project description:Microarray 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. Experiment Overall Design: Affymetrix expression profiling was used to study gene expression in immature ear tissue from maize. Three biological replicates were performed for four different genotypes; B73, Mo17, B73xMo17 and Mo17xB73.
2008-06-16 | E-GEOD-8176 | biostudies-arrayexpress
Project description:The contribution of epigenetic alterations to natural variation for gene transcription levels remains unclear. In this study, we investigated the functional targets of the maize chromomethylase ZMET2 in multiple inbred lines to determine whether epigenetic changes conditioned by this chromomethylase are conserved or variable within the species. Gene expression microarrays were hybridized with RNA samples from the inbred lines B73 and Mo17, and from near-isogenic derivatives containing the loss-of-function allele zmet2-m1. A set of 126 genes that displayed statistically significant differential expression in zmet2 mutants relative to wild-type plants in at least one of the two genetic backgrounds were identified. Analysis of the transcript levels in both wild-type and mutant individuals revealed that only 10% of these genes were affected in zmet2 mutants in both B73 and Mo17 genetic backgrounds. Over 80% of the genes with expression patterns affected by zmet2 mutations display variation for gene expression between wild-type B73 and Mo17 plants. Further analysis was performed for seven genes that were transcriptionally silent in wild-type B73, but expressed in B73 zmet2-m1, wild-type Mo17 and Mo17 zmet2-m1 lines. Mapping experiments confirmed that the expression differences in wild-type B73 relative to Mo17 inbreds for these genes were caused by cis-acting regulatory variation. Methylation-sensitive PCR and bisulphite sequencing demonstrated that for five of these genes the CpNpG methylation in the wild-type B73 genetic background was substantially decreased in the B73 zmet2-m1 mutant and in wild-type Mo17. A survey of eight maize inbreds reveals that each of these five genes exhibit transcriptionally silent and methylated states in some inbred lines and unmethylated, expressed states in other inbreds, providing evidence for natural variation in epigenetic states for some maize genes. Keywords: mutant versus wild-type comparison in two inbred genotypes
2007-12-01 | GSE8188 | GEO
Project description:The contribution of epigenetic alterations to natural variation for gene transcription levels remains unclear. In this study, we investigated the functional targets of the maize chromomethylase ZMET2 in multiple inbred lines to determine whether epigenetic changes conditioned by this chromomethylase are conserved or variable within the species. Gene expression microarrays were hybridized with RNA samples from the inbred lines B73 and Mo17, and from near-isogenic derivatives containing the loss-of-function allele zmet2-m1. A set of 126 genes that displayed statistically significant differential expression in zmet2 mutants relative to wild-type plants in at least one of the two genetic backgrounds were identified. Analysis of the transcript levels in both wild-type and mutant individuals revealed that only 10% of these genes were affected in zmet2 mutants in both B73 and Mo17 genetic backgrounds. Over 80% of the genes with expression patterns affected by zmet2 mutations display variation for gene expression between wild-type B73 and Mo17 plants. Further analysis was performed for seven genes that were transcriptionally silent in wild-type B73, but expressed in B73 zmet2-m1, wild-type Mo17 and Mo17 zmet2-m1 lines. Mapping experiments confirmed that the expression differences in wild-type B73 relative to Mo17 inbreds for these genes were caused by cis-acting regulatory variation. Methylation-sensitive PCR and bisulphite sequencing demonstrated that for five of these genes the CpNpG methylation in the wild-type B73 genetic background was substantially decreased in the B73 zmet2-m1 mutant and in wild-type Mo17. A survey of eight maize inbreds reveals that each of these five genes exhibit transcriptionally silent and methylated states in some inbred lines and unmethylated, expressed states in other inbreds, providing evidence for natural variation in epigenetic states for some maize genes. Experiment Overall Design: The zmet2-m1 mutant allele was backcrossed into two inbred backgrounds, B73 and Mo17. RNA was isolated from 6 biological replicates of B73 wild-type plants, 6 biological replicates of B73 zmet2-m1 mutant plants; 3 biological replicates of Mo17 wild-type plants and 3 biological replicates of Mo17 zmet2-m1 mutant plants.
2008-06-17 | E-GEOD-8188 | biostudies-arrayexpress
Project description:Heterosis is the phenomenon whereby the progeny of particular inbred lines have enhanced agronomic performance relative to both parents. Although several hypotheses have been proposed to explain this fundamental biological phenomenon, the responsible molecular mechanisms have not been determined. The maize inbred lines B73 and Mo17 produce a heterotic F1 hybrid. Global patterns of gene expression were compared in seedlings of these three genotypes using a microarray that contains 13,999 cDNAs. Using an estimated 15% false discovery rate as a cut-off, 1,367 ESTs (9.8%) were identified as being significantly differentially expressed among genotypes. All possible modes of gene action were observed, including additivity, high- and low-parent dominance, under-dominance, and over-dominance. The largest proportion of the ESTs (78%, 1,062/1,367) exhibited expression patterns that are not statistically distinguishable from additivity. Even so, 22% of the differentially regulated genes exhibited non-additive modes of gene expression. Classified on the basis of significant pair-wise comparisons of genotype means, 181 of these 305 genes exhibited high-parent dominance and 23 exhibited low-parent dominance. In addition, 44 genes exhibited under- or over-dominant gene action. These findings are consistent with the hypothesis that multiple molecular mechanisms contribute to heterosis, including over-dominance Keywords: Genotype Comparison The inbreds B73 (Schnable Lab Accession #660) and Mo17 (Schnable Lab Accession #2618) used in this study were derived by self-pollination from stocks originally obtained from Don Robertson (Iowa State University) and Mike Lee (Iowa State University), respectively. Mo17 was crossed as a female by B73 to generate the F1. Kernels from three different seed sources (ears) per genotype were used in the experimental design. Prior to microarray analyses genotypes were confirmed by genotyping DNA extracted from each seed source using co-dominant IDP genetic markers that distinguish B73 from Mo17 (Fu et al., in preparation). Ten biological replications of B73, Mo17, and their F1 (Mo17xB73) were grown under highly controlled conditions in a randomized complete block design. For each replication, the B73, Mo17, and F1 samples were hybridized to three two-color cDNA microarrays using a loop design such that each loop included all pairwise comparisons between genotypes. RNA pools for each genotype were alternately labeled providing dye balance within each loop. After hybridization, one biological replicate was removed due to poor quality. The final analysis incorporated 27 microarray slides (3 slides for each of nine high-quality biological replicates).
2010-06-26 | E-GEOD-4473 | biostudies-arrayexpress
Project description:Expression profiling analyses for eight maize inbreds reveals extensive transcriptional variation. Many genes exhibit presence-absence variation among the inbred lines. Experiment Overall Design: Affymetrix expression profiling was used to study gene expression in aerial tissue from 11-day seedlings of maize. Three biological replicates were performed for eight different inbred lines; B37, B73, B84, Mo17, Oh43, B14a, Wf9 and W22.
2008-06-11 | E-GEOD-10237 | biostudies-arrayexpress
Project description:Expression 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. Experiment Overall Design: Affymetrix expression profiling was used to study gene expression in aerial tissue from 11-day seedlings of maize. Three biological replicates were performed for nine different genotypes; B37, B73, B84, Mo17, Oh43, B37xB73, B84xB73, Oh43xB73 and Oh43xMo17.
2008-06-11 | E-GEOD-10236 | biostudies-arrayexpress