Whole-genome gene expression profiling revealed genes and pathways potentially involved in regulating interactions of soybean with cyst nematode (Heterodera glycines Ichinohe)
ABSTRACT: Background: Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is the most devastating pathogen of soybean. Many gene expression profiling studies have been conducted to investigate the responses of soybean to the infection by this pathogen using primarily the first-generation soybean genome array that covered approximately 37,500 soybean transcripts. However, no study has been reported yet using the second-generation Affymetrix soybean whole-genome transcript array (Soybean WT array) that represents approximately 66,000 predicted soybean transcripts. Results: In the present work, the gene expression profiles of two soybean plant introductions (PIs) PI 437654 and PI 567516C (both resistant to multiple SCN races) and cultivar (cv.) Magellan (susceptible to SCN) were compared in the presence or absence of the SCN inoculum at different time points (3 and 8 days post-inoculation). For this purpose, the Soybean WT array, which covers many more predicted soybean transcripts than the first-generation Affymetrix soybean array, was employed. Data analysis revealed that the two resistant soybean lines showed distinctive gene expression profiles from each other and from Magellan not only in response to the SCN inoculation, but also in the absence of SCN. Overall, 1,413 genes and many pathways, such as defense and hormonal pathways, were revealed to be differentially regulated. Among them, 297 genes were constitutively regulated in the two resistant lines (compared with cv. Magellan) and 1,146 genes were responsive to the SCN inoculation in the three lines, with 30 genes regulated both constitutively and by SCN. In addition to the findings similar to those in the published work, many genes involved in ethylene, protein degradation, and phenylpropanoid pathways were also revealed differentially regulated in the present study. GC-rich elements (e.g., GCATGC) were found over-represented in the promoter regions of certain groups of genes. These have not been observed before, and could be new defense-responsive regulatory elements. Conclusions: Different soybean lines showed different gene expression profiles in the presence and absence of the SCN inoculum. Both inducible and constitutive gene expression may contribute to resistance to multiple SCN HG Types in the resistant soybean PI lines. Ethylene, protein degradation, and phenylpropanoid pathways, as well as many other pathways reported previously, may play important roles in mediating the soybean-SCN interactions. The revealed genes, pathways, and promoter elements can be further explored to regulate or engineer soybean for resistance to SCN. Three soybean lines were compared in the study: Magellan (susceptible to SCN), PI 437654 (PI654; resistant to SCN), and PI 567516C (PI516C; resistant to SCN). Overall, thirty samples, including two biological replicates for each sample, were analyzed.
Project description:Analysis of gene expression data from four genetically diverse wild soybean accessions helps reveal both sensitive and resistant responses of the plants to increased ozone levels. Results help characterize genetic response of wild soybean to ozone stress and could help provide information on genetic resources for creating ozone-tolerant soybean breeding lines. Overall design: 2 sensitive genotypes (PI 407179 and PI 424007) and 2 resistant genotypes (PI 424123 and PI 507656) were replicated in 4 complete block designs and subjected to either 75 parts per billion (ppb) ozone or a control of charcoal-filtered conditions (< 10 ppb ozone). Total RNA was isolated from the first three trifoliate of each plant and deep sequenced using Illumina HiSeq 2500.
Project description:The suprachiasmatic nucleus (SCN) acts as the central clock to coordinate circadian oscillations in mammalian behavior, physiology and gene expression. Despite our knowledge of the circadian transcriptome of the SCN, how it impacts genome-wide protein expression is not well understood. Here, we interrogated the murine SCN proteome across the circadian cycle using SILAC-based quantitative mass spectrometry.
Project description:To identify potential mechanisms underlying the phenotype of miR-132/212 KO mice under short photoperiods, we used quantitative mass spectrometry to analyze the SCN proteomes of miR-132/212 KO and WT mice under a 8:16 LD schedule at 4 time points, spaced 6h apart, across a 24h cycle (n=4 per time point per genotype). Quantification was achieved using a spike-in reference of three murine neural cell lines, including Neuro2A, and the adult mouse hypothalamic cell lines mHypoA-2/28 (CLU188) and mHypoA-SCN mix (CLU497) that had been labeled by SILAC (stable isotope labeling by amino acids in cell culture).
Project description:To determine whether immortalized cells derived from the rat SCN (SCN2.2) retain intrinsic rhythm-generating properties characteristic of the SCN, oscillatory properties of the SCN2.2 transcriptome were analyzed and compared to those found in the rat SCN in vivo using rat U34A Affymetrix GeneChips. This SuperSeries is composed of the following subset Series:; GSE1654: Circadian Profiling of the Transcriptome in Immortalized Rat SCN Cells (3 biological replicates); GSE1673: Circadian Profiling of the Transcriptome in Immortalized Rat SCN Cells: Comparison to Long-Evans Rat SCN Experiment Overall Design: Refer to individual Series
Project description:We performed a circadian RNA expression profile of the mammalian biological clock, the suprachiasmatic nucleus (SCN) in C57/BL6 mice, at 2-hour resolution using microarrays, and at 6-hour resolution using RNA-seq. 24 samples total covering 24 time points, with no replicates. SCN samples from mouse brains collected every 2 hours for 2 days (24 samples total).
Project description:The timing of daily “circadian” behavior can be highly variable among different individuals, and twin studies suggest that about half of this variability is environmentally controlled. Similar plasticity can be seen in mice exposed to an altered lighting environment – for example, 22-hour days instead of 24-hour ones – which stably alters the genetically determined period of circadian behavior for months. The mechanisms mediating these environmental influences are unknown. Here, we show that transient exposure of mice to such lighting stably alters global transcription in the suprachiasmatic nucleus of the hypothalamus (the SCN, the “master clock” tissue determining circadian behavior in mammals). We have also showed that, these changes in transcription are due to change in DNA methylation in the SCN. Indeed, genome-wide methylation profiling revealed global alterations in promoter DNA methylation in the SCN. Importantly, infusion of a methyltransferase inhibitor to the SCN during 22-hour days suppressed period changes. We also found that these behavioral and DNA methylation changes are reversible upon entrainment to 24-hours days. We conclude that the SCN utilizes DNA methylation as a mechanism to drive circadian clock plasticity. MeDIP array of profiling, demonstrated that genomicDNA methylation changes in mice entrained to short-T cycle. comparison of methylation profile in the suprachiasmatic nuclei of mice entrained to normal T-cycle and short T-cycle
Project description:We performed a circadian RNA expression profile of the mammalian biological clock, the suprachiasmatic nucleus (SCN) in C57/BL6 mice, at 2-hour resolution using microarrays, and at 6-hour resolution using RNA-seq. 8 samples total covering 8 time points, with no replicates. SCN samples from mouse brains collected every 6 hours for 2 days (8 samples total).