Project description:Yersinia pestis is the etiology of plague that is able to sense cell density by quorum sensing. The function of quorum sensing in Y.pestis is not clear. Here, the process of quorum sensing was investigated by comparing transcript profiles when three quorum sensing synthase genes are knocked out. Two strains, â??pgm (pigmentation-negative) mutant R88 as treatment and 3XQS mutant with mutation (â??pgm, â??ypeIR, â??yspIR, and â??luxS) R115 as control are used in this analysis. Six independent RNA samples from R115 cultures were paired with six independent RNA samples from R88 cultures for hybridization to six two-color microarrays. Dye-swap design was used to remove the Cy5 and Cy3 dye bias.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of quorum sensing was investigated by comparing transcript profiles when three quorum-sensing synthase genes are knocked out. Two strains, M-bM-^HM-^Fpgm (pigmentation-negative) mutant R88 as treatment and quorum sensing null strain R115 with mutations (M-bM-^HM-^Fpgm, M-bM-^HM-^FypeIR, M-bM-^HM-^FyspIR, and M-bM-^HM-^FluxS) as control, are used in this analysis. Six independent RNA samples from R115 cultures were paired with six independent RNA samples from R88 cultures for hybridization to six two-color microarrays. A dye-swap design was used to remove the Cy5 and Cy3 dye bias.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of AHL quorum sensing was investigated by comparing transcript profiles when two AHL quorum-sensing signals are added in. The strain âpgm (pigmentation-negative) mutant R88 was called wild type. The two AHLs signals are N-(3-Oxooctanoyl)-L-homoserine lactone and N-Hexanoyl-DL-homoserine lactone.The control consisted of cells grown and treated under the same conditions without added signals. Six independent RNA samples from R88 cultures were paired with six independent RNA samples from two AHLs added cultures for hybridization to six two-color microarrays. A dye-swap design was used to remove the Cy5 and Cy3 dye bias.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of quorum sensing was investigated by comparing transcript profiles when three quorum-sensing signals are added in. The strain M-bM-^HM-^Fpgm (pigmentation-negative) mutant R88 was used as wild type. The three signals are AI-2, AHLs (N-(3-Oxooctanoyl)-L-homoserine lactone and N-Hexanoyl-DL-homoserine lactone).The control consisted of cells grown and treated under the same conditions without added signals. Six independent RNA samples from Y. pestis CO92 M-bM-^HM-^Fpgm cultures were paired with six independent RNA samples from 3 signals added cultures for hybridization to six two-color microarrays. A dye-swap design was used to remove the Cy5 and Cy3 dye bias.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of autoinducer 2 (AI-2) quorum sensing was investigated by comparing transcript profiles when luxS gene was knocked out. The luxS gene encodes S-ribosylhomocysteinase which can produce DPD, a precursor of AI-2. The strain M-bM-^HM-^Fpgm (pigmentation-negative) mutant R88 was called wild type. The M-bM-^HM-^Fpgm M-bM-^HM-^FluxS mutant was called control. Six independent RNA samples from R88 were paired with six independent RNA samples from M-bM-^HM-^Fpgm M-bM-^HM-^FluxS mutant cultures for hybridization to six two-color microarrays. A dye-swap design was used to remove the Cy5 and Cy3 dye bias.
Project description:Yersinia pestis, the etiological agent of plague, is able to sense cell density by quorum sensing. The function of quorum sensing in Y. pestis is not clear. Here, the process of autoinducer-2 (AI-2) quorum sensing was investigated by comparing transcript profiles when AI-2 quorum-sensing signal is added in. The strain M-bM-^HM-^Fpgm(pigmentation-negative) mutant R88 was used as wild type. The control consisted of cells grown and treated under the same conditions without added signals. Six independent RNA samples from Y. pestis CO92 M-bM-^HM-^Fpgm cultures were paired with six independent RNA samples from AI-2 signal added cultures for hybridization to six two-color microarrays. A dye-swap design was used to remove the Cy5 and Cy3 dye bias.
Project description:The following study was conducted to better understand the genetics of the spatial and temporal development of rice, especially as this relates to the development of lignocellulosic tissues. To do so, an oligonucleotide array was designed and created by the Plant Sciences Institute at Iowa State University. A total of 43,776 spots were printed on two separate platforms, the first contained 23,040 spots while the second contained 20,736. RNA was collected from nodes of rice seedlings at several different time points, as nodes are highly lignified tissues. Comparisons were performed to identify those genes exhibiting differential regulation across time at an anatomical position as well as across anatomical distance. For example, node 1 was compared across days 46, 53, 60, and 67 and at day 67 node 1 was compared to nodes 2, 3, and 4. Similar comparisons were performed for nodes 2, 3, and 4 where applicable. Keywords: Time course and anatomical development in rice For each comparison, 6 replicates and multiple power settings were considered. Dye-swaps were performed between replicates. A diagram of the comparisons made in this experiment may be found in ISU_RiceArray_LoopDesign.pdf (linked below as a Supplementary file).
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.