ABSTRACT: Quantify gene expression by measurement of mRNA in maize inbred line Mo17 mRNA-seq used as part of the validation of CAGE results used for the genome-wide location and dynamic of maize core promoters obtained from the experimental establishment of the TSSs coordinates 4 samples
Project description:P1 encodes an R2R3-MYB transcription factor responsible for the accumulation of insecticidal flavones in maize silks and red phlobaphene pigments in pericarps and other floral tissues, which contributed to making P1 an important visual marker since the dawn of modern genetics. We conducted RNA-Seq using pericarps at two different stages, 14 and 25 days after pollination (DAP). High-throughput sequencing using the Illumina platform resulted in the generation of ~20 million high quality reads, from which ~90% aligned to the recently completed maize genome sequence corresponding to ~5 million reads for each one of the four samples. Examination of two different RNA samples from two different stages of maize pericarp tissues.
Project description:P1 encodes an R2R3-MYB transcription factor responsible for the accumulation of insecticidal flavones in maize silks and red phlobaphene pigments in pericarps and other floral tissues, which contributed to making P1 an important visual marker since the dawn of modern genetics. We conducted RNA-Seq using from maize silks obtained at 2-3 days after emergence. High-throughput sequencing using the Illumina platform resulted in the generation of ~14 million high quality reads, corresponding to ~7 million reads for each sample, from which 76% aligned to the maize genome. Examination of two different RNA samples from maize silks obtained at 2-3 days after emergence
Project description:Transcriptome profiles of MATZ and BETL tissues are compared across three stages of development. Sugars and other nutrients unloaded from vascular tissues in the MATZ are imported by the BETL for utilization by the developing endosperm. Pronounced changes in gene expression occur in both tissues during kernel development. RNAseq data were obtained from duplicate tissue samples isolated by cryomicrodissection of developing maize kernels at three developmental time points; 8 days post-pollination (DAP), 14 DAP and 20 DAP.
Project description:Purpose: To study the effects of drought at the transcriptomic level on two different actively dividing maize tissue: the ovaries, and the leaf meristem Methods: The Illumina reads were mapped to the maize B73 reference genome using Tophat followed by transcriptome reconstruction using Cufflinks. The FPKM valuse were extracted from cufflinks output and an R package called Limma was used to identify differentially expressed genes under drought under both tissues Results and Conclusions: Different processes which were differentially expressed under drought in both tissues were identified and analyzed in detail. A working hypothesis was formulated to account for the observed susceptibility of the reproductive tissue when compared to the robust response of the vegetative tissue. This analysis also servers as a basis for future study on drought-induced embryo abortion. Maize (Zea mays) plants of inbred line B73 were grown in the green house under well watered and drought stress conditions until they reached the reproductive stage (at the onset of silk emergence). For the drought stress two to three days after irrigation was withheld, the plants were hand pollinated, and 24 hours after pollination measurements and samples were collected for transcriptome analysis. At the end of the drought period (1DAP) the basal leaf meristem of the three youngest leaves and the ovary tissues were sampled for Illumina deep sequencing. Samples were labeled as well watered control leaf meristem (MLC), well watered control ovaries/ "cob" (MCC), drought stressed leaf meristem (MLD) and drought stressed ovary tissue (MCD). There are 8 libraries in total including one biological replicate for each condition.
Project description:Epigenetic modification plays important roles in plant and animal development. DNA methylation can impact the transposable element (TE) silencing, gene imprinting and regulate gene expression.Through a genome-wide analysis, DNA methylation peaks were respectively characterized and mapped in maize embryo and endosperm genome. Distinct methylation level across maize embryo and endosperm was observed. The maize embryo genome contained more DNA methylation peaks than endosperm. However, the endosperm chloroplast genome contained more DNA methylation peaks to compare with the embryo chloroplast genome. DNA methylation regions were characterized and mapped in genome. More CG island (CGI) shore are methylated than CGI in maize suggested that DNA methylation level is not positively correlated with CpG density. The DNA methylation occurred more frequently in the promoter sequence and transcriptional termination region (TTR) than other regions of the genes. The result showed that 99% TEs we characterized are methylated in maize embryo, but some (34.8%) of them are not methylated in endosperm. Maize embryo and endosperm exhibit distinct pattern/level of methylation. The most differentially methylated two regions between embryo and endosperm are High CpG content promoters (HCPs) and high CpG content TTRs (HCTTRs). DNA methylation peaks distinction of mitochondria and chloroplast DNA were less than the nucleus DNA. Our results indicated that DNA methylation is associated with the gene silencing or gene activation in maize endosperm and embryo. Many genes involved in embryogenesis and seed development were found differentially methylated in embryo and endosperm. We found 17 endosperm-specific expressed imprinting genes were hypomethylated in endosperm and were hypermethylated in embryo. The expression of a maize DEMETER -like (DME-like) gene and MBD101 gene (MBD4 homolog) which direct bulk genome DNA demethylation were higher in endosperm than in embryo. These two genes may be associated with the distinct methylation level across maize embryo and endosperm.The methylomes of maize embryo and endosperm was obtained by MeDIP-seq method. The global mapping of maize embryo and endosperm methylation in this study broadened our knowledge of DNA methylation patterns in maize genome, and provided useful information for future studies on maize seed development and regulation of metabolic pathways in different seed tissues. Examination of DNA methylated modifications in 2 maize tissues.
Project description:De novo centromeres originate occasionally from non-centromeric regions of chromosomes, providing an excellent model system to study centromeric chromatin. The maize mini-chromosome Derivative 3-3 contains a de novo centromere, which was derived from a euchromatic site on the short arm of chromosome 9 that lacks traditional centromeric repeat sequences. Our previous study found that the CENH3 binding domain of this de novo centromere is only 288 kb with a high-density gene distribution with low-density of transposons. Here we applied next generation sequencing technology to analyze gene transcription, DNA methylation for this region. Our RNA-seq data revealed that active chromatin is not a barrier for de novo centromere formation. Bisulfite-ChIP-seq results indicate a slightly increased DNA methylation level after de novo centromere formation, reaching the level of a native centromere. These results provide insight into the mechanism of de novo centromere formation and subsequent consequences. RNA-seq was carried out using material from seedling and young leaves between control and Derivative 3-3. Bisulfite-ChIP-seq was carried out with anti-CENH3 antibodies using material from young leaves in Derivative 3-3.
Project description:Analysis of the maize alternative splicing landscape, including transcript discovery and mapping of genotype-dependent variations in alternative splicing using B73, Mo17 and the SX19 inbred mapping population Total RNA was isolated from 5 week old leaves of hydroponically grown maize plants and used to construct RNA seq libraries
Project description:We sequenced mRNA from from four segments along a developing 9 day old third maize leaf of WT W22 accession and ZmDCT2 KO (in W22 background - dct2-1::Ac) plants, to identify changes in gene expression in dct2-1::Ac as a response to the loss of ZmDCT2 function. The segments were referenced relative to the position of the ligule of leaf 2 as this point represents the source-sink boundary in a wild-type leaf and the transition from shaded leaf tissue to fully light exposed. Segment -4 was isolated at the base of the leaf blade that is photosynthetically inactive, -1, defined as the sink to source transition zone (just below the point of leaf emergence from the whorl), segment +4, from a fully light exposed and photosynthetically active region in the mid-leaf (maturation zone), and +10, the tip of the leaf and the terminally differentiated tissue
Project description:Maize plants defective for the AGO104 protein show defects in chromatin condensation during meiosis, and subsequent failure to segregate chromosomes. AGO104 is a member of the ARGONAUTE family of proteins. AGO104 accumulates specifically in somatic cells surrounding the female meiocyte, suggesting a mobile signal rather than cell-autonomous control. AGO104 is necessary for non-CG methylation of centromeric and knob repeat DNA. Digital Gene Expression Tag Profiling experiments using high-throughput sequencing show that AGO104 influences the transcription of many targets in the ovaries, with a strong effect on centromeric repeats. AGO104 is related to Arabidopsis AGO9, but while AGO9 acts to repress germ cell fate in somatic tissues, AGO104 acts to repress somatic fate in germ cells. Thus, female germ cell development in maize is dependent upon conserved small RNA pathways acting non-cell autonomously in the ovule. Interfering with this repression leads to apomixis-like phenotypes in maize. Profiling of gene expression in mutant versus wilt type ovaries.