Dosage effect on genes in maize copy-number alterations
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ABSTRACT: We sequenced 9 mRNA samples taken from the 14-day old maize seedling tissue. These 9 samples are comprised by 3 genotypes and 3 replications. Examination of mRNA levels in each individual genotype.
Project description:We sequenced 9 mRNA samples taken from the 14-day old maize seedling tissue. These 9 samples are comprised by 3 genotypes and 3 replications.
Project description:We sequenced 10 small RNA samples. 6 samples were taken from the 14-day old maize seedling tissue, and the other 4 samples were taken from 14-day old maize root tissue. Examination of small RNA levels in each individual sample
Project description:We sequenced 10 small RNA samples. 6 samples were taken from the 14-day old maize seedling tissue, and the other 4 samples were taken from 14-day old maize root tissue.
Project description:All above ground organs of higher plants are ultimately derived from specialized organogenic structures termed shoot apical meristems (SAMs). The SAM exhibits distinctive structural organization, marked by cell layering. Maize SAMs are comprised of two cell layers, L1 (single cell layered tunica) and L2 (corpus). To identify genes required for layer-specific functions intact maize SAMs were fixed, embedded in paraffin and sectioned. L1 and L2 cells were isolated from these sections via laser capture microdissection (LCM). RNA was isolated from six biological replications of L1 and L2, amplified and hybridized to microarrays spotted with ~37,000 maize cDNA clones. This experiment identified ~700 ESTs that are preferentially expressed in the L1 or the L2 (P <0.001). The L1-up-regulated ESTs included ZmOCL1 and ZmOCL4, which are known to exhibit L1-specific expression in the maize SAM. The L2-up-regulated ESTs included KNOTTED1, whose transcripts are known to accumulate in the L2 but not in the L1 of the maize SAM. Differentially expressed ESTs included genes involved in transcription, signal transduction, transport and metabolism, many of which are novel candidates that are required for layer-specific functions in the maize SAM. Several L1-up-regulated ESTs were annotated as yabby family genes or basic helix-loop-helix transcription factor-like genes, which have not previously been reported as having layer-specific expression in the SAM. Novel WW domain-containing genes (WW genes) were identified in this study. The WW domain mediates protein-protein interactions, often with signal transduction components. These WW genes were substantially up-regulated in the L1 relative to the L2. Keywords: Cell Type Comparison An experimental aim is to identify genes that are differentially expressed in distinct histological cell layers of maize SAM by comparing the transcript accumulation between L1 (single cell layered tunica) and L2 (corpus) using cDNA microarrays that have over 37,000 informative spots from maize.
Project description:Heterosis (hybrid vigor) refers to the superior performance of hybrid progeny relative to their parents. Although widely exploited in agriculture, the mechanisms responsible for heterosis are not well understood. As a monoecious organism, a given maize plant can be used as both male and female parents of crosses. Regardless of the cross direction, the maize inbred lines B73 and Mo17 produce hybrids that substantially out-perform their parents. These reciprocal hybrids differ phenotypically from each other despite having identical nuclear genomes. Consistent with these phenotypic observations, 30-50% of genes were differentially expressed between these reciprocal hybrids. An eQTL experiment conducted to better understand the regulation of gene expression in inbred and hybrid lines detected ~4,000 eQTL associations. The majority of these eQTL act in trans to regulate expression of genes on other chromosomes. Surprisingly, many of the trans-eQTL, when heterozygous, differentially regulated transcript accumulation in a manner consistent with gene expression in the hybrid being regulated exclusively by the paternally transmitted allele. The design of the eQTL experiment controlled for cytoplasmic and maternal effects, suggesting that widespread paternal genomic imprinting contributes to the regulation of gene expression in maize hybrids. Keywords: eQTL, parent-of-origin GPL4521 - SAM1.2 (Reciprocal Hybrid Comparison): Six replications of B73xMo17 and Mo17xB73 were grown in growth chambers to tightly control environmental variation. Seeds from each genotype were taken from a single source (ear) for all six replications. Within each replication, genotypes were randomly assigned growth locations. Six healthy seedlings for each genotype and replication were harvested at two weeks of age. For each replication, B73xMo17 and Mo17xB73 were hybridized to the SAM1.2 microarray (GPL4521) using a randomized, alternate dye assignment. GPL3333 - SAM1.1 and GPL3538 - SAM3.0 (eQTL Experiment): Four biological replications of the RIL, B73xRIL, and Mo17xRIL cross-types were planted in growth chambers using seed from a single source for each genotype. Each RIL and its crosses onto B73 and Mo17 were planted using a split-plot design with RIL group (RIL and its cross onto B73 and Mo17) as the whole-plot treatment factor and cross-type (RIL, B73xRIL, and Mo17xRIL) as the split-plot treatment factor. The whole-plot portion of the experiment was designed as a randomized complete block design with four replications carried out on four separate occasions in the same environment. For the split-plot portion of the design, twelve seedlings of each RIL and its crosses were randomized within two adjacent flats in a growth chamber (six healthy seedlings per genotype were randomly chosen and pooled at harvest). For each replication, RIL, B73xRIL, and Mo17xRIL cross-types were hybridized to custom cDNA microarrays using a loop design such that each loop included all pairwise comparisons between the RIL and its crosses with B73 and Mo17. Four biological replications were hybridized to the SAM1.1 (GPL3333) array and two of the four biological replications were hybridized to SAM3.0 (GPL3538). RNA samples were alternately labeled to provide dye balance within each loop and replication. GPL8734 - Gene Expression between two maize reciprocal hybrids Heterosis refers to the enhanced agronomic performance of a hybrid relative to its (usually) inbred parents. We have previously documented widespread differences in gene expression in the B73xMo17 hybrid relative to its inbred parents B73 and Mo17 (Swanson, et al., 2006, PNAS). The reciprocal B73xMo17 and Mo17xB73 hybrids are both highly heterotic, but despite having identical nuclear genomes exhibit statistically significant differences in multiple traits. RNA-seq experiment was conducted to compare the gene expression globally between the two reciprocal hybrids. 1 samples from B73XMo17 and Mo17XB73 RNAs were extracted from a single replication of 14-day-old B73xMo17 and Mo17xB73 seedlings. RNAs were purified using DNaseI treatment followed by cleanup with the RNeasy Plant Mini Kit (Qiagen, Valencia, CA) as per manufacturer instructions. Sequencing library construction was completed using the Illumina mRNA-Seq sample preparation kit. Processed data file 'ZmB73_4a.53_filtered_genes.fasta' and its README file are linked below as supplementary files. The fasta file contains the gene model ID and corresponding sequence generated from maize genome project. This fasta file was used for the following samples: GSM418173, GSM418174, GSM420173, GSM420174, GSM422828, GSM422829.
Project description:We tested four gene enrichment and complexity reduction target preparation methods for scoring SFPs on the Affymetrix GeneChip 18k Maize Genome Array (âMaize GeneChipâ). Methylation filtration (MF), Cot filtration (CF), mRNA-derived cRNA, and amplified fragment length polymorphism (AFLP) methods were applied to three diverse maize inbred lines (B73, Mo17, and CML69) with three replications per line (36 Maize GeneChips). Due to large amounts of repetitive, mobile DNA, the maize genome requires a target preparation method that offers both a high level of gene enrichment and accurate scoring of SFPs. The objectives of this research are (i) to determine which target preparation method (CF, MF, mRNA, or AFLP) optimally enriches for gene sequences complementary to probe sequences on the Affymetrix GeneChip Maize Genome Array and (ii) to estimate SFP detection power for each target method. The AFLP technology is covered by patents, and patent applications owned by Keygene N.V. AFLP is a registered trademark of Keygene N.V. GeneChip. This work was supported in part by U.S. National Science Foundation grant DBI-0321467 and USDA-ARS. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the USDA. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Michael Gore. The equivalent experiment is ZM10 at PLEXdb.] Experiment Overall Design: protocol: mRNA - genotype: B73 maize inbred(3-replications) Experiment Overall Design: protocol: mRNA - genotype: Mo17 maize inbred(3-replications) Experiment Overall Design: protocol: mRNA - genotype: CML69 maize inbred(3-replications) Experiment Overall Design: protocol: Cot filtration (CF) - genotype: B73 maize inbred(3-replications) Experiment Overall Design: protocol: Cot filtration (CF) - genotype: Mo17 maize inbred(3-replications) Experiment Overall Design: protocol: Cot filtration (CF) - genotype: CML69 maize inbred(3-replications) Experiment Overall Design: protocol: Methylation filtration (MF) - genotype: B73 maize inbred(3-replications) Experiment Overall Design: protocol: Methylation filtration (MF) - genotype: Mo17 maize inbred(3-replications) Experiment Overall Design: protocol: Methylation filtration (MF) - genotype: CML69 maize inbred(3-replications) Experiment Overall Design: protocol: Amplified fragment restriction polymorphism (AFLP) - genotype: B73 maize inbred(3-replications) Experiment Overall Design: protocol: Amplified fragment restriction polymorphism (AFLP) - genotype: Mo17 maize inbred(3-replications) Experiment Overall Design: protocol: Amplified fragment restriction polymorphism (AFLP) - genotype: CML69 maize inbred(3-replications)
Project description:Copy-number alterations are widespread in animal and plant genomes, but their immediate impact on gene expression is still unclear. In animals, copy-number alterations usually exhibit dosage effects, except for sex chromosomes which tend to be dosage compensated. In plants, genes within small duplications (<100 kb) often exhibit dosage-dependent expression, whereas large duplications (>50 Mb) are more often dosage compensated. However, little or nothing is known about expression in moderately-sized (1-50 Mb) segmental duplications, and about the response of small RNAs to dosage change. Here, we compared maize (Zea mays) plants with two, three, and four doses of a 14.6-Mb segment of chromosome 1 that contains ∼300 genes. Plants containing the duplicated segment exhibit dosage-dependent effects on ear length and flowering time. Transcriptome analyses using GeneChip and RNA-sequencing methods indicate that most expressed genes and unique small RNAs within the duplicated segments exhibit dosage-dependent transcript levels. We conclude that dosage effect is the predominant regulatory response for both genes and unique small RNA transcripts in the segmental dosage series we tested. To our knowledge this is the first analysis of small RNA expression in plant gene dosage variants. Because segmental duplications comprise a significant proportion of eukaryotic genomes, these findings provide important new insight into the regulation of genes and small RNAs in response to dosage changes.
Project description:1 g samples of maize seedling leaf bases were collected from the wild-type (Zheng58) plants and the mutants (bzu3-2). we undertook glycoproteomics analyses of the N-glycans. Based on the libraries of maize protein group and plant N-glycosylation modification in the Uniprot database, we identified 2,194 intact N-glycopeptides, and quantified 181 differentially expressed intact N-glycopeptides (DEGPs)
Project description:All above ground organs of higher plants are ultimately derived from shoot apical meristems (SAMs). The SAM exhibits distinctive structural organization, and monocot SAMs such as maize are comprised of two cell layers, a single cell layered tunica (L1) and a corpus (L2). Although recent research has revealed roles of these cell layers in the SAM, intra- and inter-cell-layer signaling networks involved in organ development remain largely unknown except for a few differentially expressed genes. Here, we used Illumnia technology to conduct RNA-seq of L1 and L2 cell layers in maize B73 maize shoot apical meristem. Single sequencing library was constructed for L1 and L2 cell layer. Each library was sequenced using 2 lanes on a Solexa flow cell. Processed data file 'ZmB73_4a.53_filtered_genes.fasta' and its README file are linked below as supplementary files. The fasta file contains the gene model ID and corresponding sequence generated from maize genome project. This fasta file was used for the following samples: GSM418173, GSM418174, GSM420173, GSM420174, GSM422828, GSM422829.
Project description:The goal of the experiment was to perform a large scale study of circadian regulation of gene expression in maize. To identify maize genes with expression regulated by the circadian clock, transcript levels in the aerial tissues of young maize seedlings were determined by transcriptional profiling with the Affymetrix GeneChip Maize Genome Array. Maize inbred B73 seedlings were grown inside Conviron growth chamber. B73 seedlings were grown for 7 days under 12 h light:12 h dark (LD) photocycles, 26° C temperature and 70% humidity. At the 8th day, seedlings were transferred to continuous light (LL) and were allowed to entrain completely for 24 h prior to tissue harvest following which tissue was harvested every 4 hours under LL conditions for a period of 48h. Therefore, for the circadian LL time course 12 time points were collected as follows (also defined as factors in the treatment section): ZT0 - 8:00 am/ subjective dawn/ Day1 ZT4 - 12:00 pm/ subjective mid-day/ Day1 ZT8 - 4:00 pm/ subjective late-day/ Day1 ZT12 - 8:00 pm/ subjective dusk/ Day1 ZT16 - 12:00 am/ subjective mid-night/ Day1 ZT20 - 4:00 am/ subjective pre-dawn/ Day1 ZT24- 8:00 am/ subjective dawn/ Day2 ZT28 - 12:00 pm/ subjective mid-day/ Day2 ZT32 - 4:00 pm/ subjective late-day/ Day2 ZT36 - 8:00 pm/ subjective dusk/ Day2 ZT40 - 12:00 am/ subjective mid-night/ Day2 ZT44 - 4:00 am/ subjective pre-dawn/ Day2 Tissue comprised of aerial portion of the seedlings (corresponding to tissue from the prop roots and up) for RNA isolation. Total RNA was isolated from the entire aerial portion of 7 day-old seedlings (corresponding to tissue from the prop roots and up) by Trizol extraction followed by Qiagen RNeasy columns and treatment with RNase-free DNase I (Qiagen; qiagen.com). RNA was isolated from 3 independent biological replicates was pooled. cRNA was generated from pooled total RNA from 3 biological replicates with the GeneChip One-Cycle Target Labeling kit according to the manufacturer’s recommendations (Affymetrix, affymetrix.com). The University of California, Berkeley Functional Genomics Laboratory hybridized samples to Affymetrix GeneChip Maize Genome Arrays and scanned the washed arrays as suggested by manufacturer. Probe sets called “Not Present” or “Marginal” on one or more microarrays were removed from the downstream analysis, as is common practice with circadian studies. Raw hybridization intensities were normalized across all twelve arrays using RMA express in Perfect Match mode. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Frank G. Harmon. The equivalent experiment is ZM28 at PLEXdb.] Continuous Light: ZT0(1-replications); Continuous Light: ZT4(1-replications); Continuous Light: ZT8(1-replications); Continuous Light: ZT12(1-replications); Continuous Light: ZT16(1-replications); Continuous Light: ZT20(1-replications); Continuous Light: ZT24(1-replications); Continuous Light: ZT28(1-replications); Continuous Light: ZT32(1-replications); Continuous Light: ZT36(1-replications); Continuous Light: ZT40(1-replications); Continuous Light: ZT44(1-replications)