Project description:This SuperSeries is composed of the following subset Series:; GSE8174: Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression - Seedling data; GSE8176: Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression - Immature ear data; GSE8179: Cis-transcriptional variation in maize inbred lines B73 and Mo17 leads to additive expression - Embryo data Experiment Overall Design: Refer to individual Series
Project description:Analysis of whole genome bisulfite data for 3 maize inbred lines (B73, PH207, and W22) with data aligned to the corresponding genome for determination of methylation level (CG, CHG, and CHH) across 100bp windows of the maize genome.
Project description:The phenomenon of heterosis describes the increased agronomic performance of heterozygous F1-plants compared to their homozygous parental inbred plants. Heterosis is already manifested during the early stages of root development in maize. The goal of this study was to identify non-additive gene expression in primary roots of maize hybrids compared to the average expression levels of their parental inbred lines. To achieve this goal a two step strategy was selected. First, a microarray preselection of non-additively expressed candidate genes was performed. Subsequently, gene expression levels in a subset of genes were determined via high throughput qRT-PCR experiments. Initial microarray experiments identified 1941 non-redundant genes which displayed non-additive gene expression in at least one of the twelve analyzed hybrids compared to the midparent value of their parental inbred lines. Comparison of these 1941 genes with non-additively expressed genes identified in maize shoot apical meristems via the same experimental procedure in the same genotypes revealed significantly less overlap than expected by pure chance supporting. This supports the notion of organ specific patterns of non-additively expressed genes. qRT-PCR analyses of 64 of the 1941 non-additively expressed genes in four different hybrids revealed that the majority of non-additively expressed genes were expressed between the high and low parent expression values and only a small fraction of genes was expressed below low or above high parent levels. Subsequently, 22 of the 64 genes that displayed non-additive expression in all four hybrids were analyzed in twelve hybrids that were generated from four inbred lines. Among those genes a superoxide dismutase 2 was expressed significantly above the midparent value in all twelve hybrids and might thus play a protective role in antioxidative defense in the primary root of maize hybrids. These findings are consistent with the hypothesis that global expression trends but also the consistent differential expression of key genes might be relevant during the organ-specific manifestation of heterosis. Keywords: Comparative genomic hybridization
Project description:High temperature is increasingly becoming one of the prominent environmental factors affecting the growth and development of maize (Zea mays L.). Therefore, it is critical to identify key genes and pathways related to heat stress (HS) tolerance in maize. Here, we identified a heat-resistant (Z58D) and heat-sensitive (AF171) maize inbred lines at seedling stage. Transcriptomic analysis identified 3,006 differentially expressed genes (DEGs) in AF171 and 4,273 DEGs in Z58D under HS treatments, respectively. Subsequently, GO enrichment analysis showed that shared upregulated genes in AF171 and Z58D involved in response to HS, protein folding, abiotic and temperature stimulus pathway. Moreover, the comparison between the two inbred lines under HS showed that response to heat and response to temperature stimulus significantly overrepresented for the 1,234 upregulated genes. Furthermore, commonly upregulated genes in Z58D and AF171 had higher expression level in Z58D than AF171. In addition, maize inbred CIMBL55 had been verified to be more tolerant than B73 and commonly upregulated genes had higher expression level in CIMBL55 than B73 under HS. The consistent results indicated that heat-resistant inbred lines may coordinate the remarkable expression of genes in order to recover from HS. Additionally, 35 DEGs were conserved among 5 inbred lines by a comparative transcriptomic analysis. Most of them were more pronounced in Z58D than AF171 at expression level. Those candidate genes may confer thermotolerance in maize.
Project description:We investigated chilling response of seedlings of three inbred maize lines: chilling tolerant S68911, chilling-sensitive S160 and moderate chilling-sensitive S50676. Kernels were germinated in wet sand in darkness at 25C. Seedlings were transferred to growth chamber (photoperiod 14/10h, temperature 24, light 250 umol quanta x m-2 x s-1), grown till the third-leaf stage and used in experiment. Chilling treatment started at the start of the dark period and lasted 38h (10h dark, 14h light,10h dark, 4h light). Growth conditions was as previously described but temperature was set to 14 (light/dark). At the same time control plants were grown as previously described. There were three biological replications of hybridization scheme.
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.
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.
Project description:Genome-wide transcriptomics experiment (RNA-seq) on proliferative tissue of eight maize inbred lines (A632, B73, B96, F7, H99, HP301, Mo17, W153R). These inbreds are used as parents in a funnel breeding design to generate an advanced recombinant maize population.