Project description:Transient genetic modification of plant protoplasts is a straightforward and rapid technique for the analysis of numerous aspects of plant biology. One drawback in the analysis of transformed protoplast suspensions is that they are a heterogeneous mix of cells that have and have not been successfully transfected. To overcome this problem, we have developed a system that employs a fluorescent positive selection marker in combination with flow cytometric analysis as well as fluorescence activated cell sorting (FACS) to isolate responses in the transfected protoplasts exclusively. This recombinase-compatible system enables high-throughput screening of genetic circuitry. Moreover, the use of FACS allows in depth downstream analysis. Lastly, over-expression is an effective means to dissect regulatory networks, especially where redundancy exists. Here, this system has been applied to the study of auxin signaling in order to investigate reporter gene activation and genome-wide transcriptional changes in response to manipulation of the auxin-response network. We have transiently over-expressed dominant negative mutant isoforms of Aux/IAA transcription factors (IAA7mII and IAA19mII; Tiwari et al., 2001) in Arabidopsis Pwer::GFP root protoplasts, making use of a RFP fluorescent positive selection marker and FACS to isolate the dually labeled (IAAnmII expressing and Pwer::GFP-positive) cells. We have compared the transcriptional differences between an empty vector control, IAA7mII and IAA19mII protoplasts that had either been treated with 5microM IAA or mock-treated for 3 hours. Experiment Overall Design: 18 samples with 3 replicates for each condition and transformation vector: 3x empty vector mock treated, 3x empty vector IAA treated, 3x IAA7mII over-expressor mock treated, 3x IAA7mII over-expressor IAA treated, 3x IAA19mII over-expressor mock treated and 3x IAA19mII over-expressor IAA treated.
Project description:Disruptions of microbiota composition by factors such as genetics have been suggested to be critical contributing factors to the growth of the worldwide epidemics of chronic illness such as metabolic diseases. IL-35-producing regulatory B and T regulatory cells are critical regulators to these illnesses. Whether microbiota-derived metabolites can regulate these IL-35+ cells maintain elusive. Here, we found gut genetic factor Reg4 associated lactobacillus could promote the generation of IL-35+ B cells through producing 3-idoleacetic acid (IAA). HuREG4IEC tg mice had markedly accumulation of IL-35+ not only in adipose tissues but also in colon tissues; whereas significantly decreased IL-35+ cells in adipose tissues and colon tissues could be detected in Reg4 KO mice. On the mechanism, IAA-mediated IL35+ B cells was through PXR), RXR and CAR in the presence of LPS. PXR KO, CAR KO and NF-B KO mice impaired the generation of IAA- IL-35+B cells. Interestingly, lower levels of IAA and IL-35 were also detected in the peripheral blood of individuals with obesity. Thus, IAA is a factor to promote the generation of IL-35+B cells to impede the development of obesity.
Project description:Lateral organ development is important for cucumber yield, while the molecular mechanism controlling leaf and floral organ development in cucumber remain elusive. In this report, a novel EMS-mutaginized mutant, round leaf (rl) was distinguished with remarkable round leaf shape, abnormal floral organ and inhibited tendril outgrowth in early development phase. Moreover, the ovule organogenesis disrupted completely in parthenocarpy fruit of rl. MutMap+ analysis revealed that RL encodes a protein kinase PINOID (CsPID, Csa1G537400). A non-synoymous SNP in the second exon of CsPID resulted in an amino-acid substitution from Arg in the wild type to Lys in the rl mutant. CsPID was down-regulated in rl mutant and preferentially expressed in young leaf, and flower buds. IAA quantification showed that rl plants exhibited a lower IAA content than wild type in ovary and blade edge. IAA immunolocalization results confirmed the IAA content alteration in rl plants. Transcriptome profile analysis further suggested IAA biosynthesis, polar transport and signal transduction genes participated in the leaf and floral development process by CsPID. Biochemical analyses showed that CsPID may regulate leaf shape by interacting with CsREV. In conclusion, this study revealed that the extensive genetic architecture of lateral organ organogenesis and development via CsPID regulating auxin polar transport action in cucumber.
Project description:We report here differences in MNase digestibility comparing murine embryonic fibroblasts (MEFs) with and without Lsh. In the first set of samples we compare primary MEFs derived from Lsh+/+ (pMEF_WT5) or Lsh-/- (pMEF_KO6) day 13.5 gestation embryos. In a second set we compare MEFs form conditional Lsh knockout mice before (GC-OHT-NC) or after 48 hours of tamoxifen inducible cre-recombinase expression (GC-OHT-2D). In a third set we compare Lsh knockout (Lsh cko) MEFs before (IAA-0h) and after 72 hours of IAA induced proteolytical degradation of Lsh (IAA-3D). In a fourth set we compare Lsh knockout MEFs before (IAA-0h-2) and after 7 hours of IAA induced proteolytical degradation of Lsh (IAA-7h) or after 24 hours (IAA-24). Lsh depletion leads to specific changes in chromatin accessibility at potential enhancer sites.
Project description:Background: Auxin/Indoleacetic acid (Aux/IAA) genes participate in the auxin signaling pathway and play key roles in plant growth and development. Although the Aux/IAA gene family has been identified in many plants, within allotetraploid Brassica napus little is known. Results: In this study, a total of 119 Aux/IAA genes were found in the genome of B. napus. They were distributed non-randomly across all 19 chromosomes and other non-anchored random scaffolds, with a symmetric distribution in the A and C subgenomes. Evolutionary and comparative analysis revealed that 111 (94.1%) B. napus Aux/IAA genes were multiplied due to ancestral Brassica genome triplication and recent allotetraploidy from B. rapa and B. oleracea. Phylogenetic analysis indicated seven subgroups containing 29 orthologous gene sets and two Brassica-specific gene sets. Structures of genes and proteins varied across different genes but were conserved among homologous genes in B. napus. Furthermore, analysis of transcriptional profiles revealed that the expression patterns of Aux/IAA genes in B. napus were tissue dependent. Auxin-responsive elements tend to be distributed in the proximal region of promoters, and are significantly associated with early exogenous auxin up-regulation. Conclusions: The Aux/IAA gene family were identified and analyzed comprehensively in the allotetraploid B. napus genome. This analysis provides a deeper understanding of diversification of Aux/IAA gene family and will facilitate further dissection of Aux/IAA gene function in B. napus.
Project description:The process of drinking water disinfection forms compounds known as disinfection byproducts (DBPs). Studies have shown that DBPs can be harmful to human and animal health. Iodoacetic acid (IAA) is a non-regulated DBP that is cytotoxic and genotoxic to mammalian cells. In addition, IAA has been shown to be an ovarian toxicant in vitro and in vivo. However, the mechanisms of action underlying IAA toxicity on ovarian follicles in vivo remain unclear. In this study, we determined whether IAA exposure alters gene expression patterns in ovarian antral follicles in mice. Adult female CD-1 mice were dosed with water or IAA (10 or 500mg/L) in the drinking water for 35-40 days. Antral follicles were dissected from the ovaries based on size (220–400 μm). Sera were collected to measure estradiol levels. RNA-sequencing was applied to uncover the global gene expression of the antral follicles in response to IAA exposure. RNA-sequencing analysis identified 410 and 653 differentially expressed genes (DEGs) in the 10 and 500mg/L IAA treatment groups (FDR < 0.1), respectively, compared to controls. Gene Ontology Enrichment analysis showed that DEGs were involved with RNA processing and regulation of angiogenesis (10mg/L) and the cell cycle, cell division, and mitotic nuclear division (500mg/L). In addition, Pathway Enrichment analysis showed that DEGs were involved in the phosphatidylinositol 3-kinase and protein kinase B (PI3K-Akt) signaling pathway, gonadotropin-releasing hormone (GnRH) signaling pathway, estrogen signaling pathway, and insulin signaling pathway (10mg/L). In the 500mg/L group, Pathway Enrichment analysis showed that DEGs were involved in the oocyte meiosis signaling pathway, GnRH signaling pathway, and oxytocin signaling pathway. In addition, RNA-sequencing analysis identified 809 DEGs when comparing the 10 and 500mg/L IAA groups (FDR < 0.1). DEGs were related to ribosome, translation, mRNA processing, oxidative phosphorylation, chromosome, cell cycle, cell division, protein folding, platelet activation, and the oxytocin signaling pathway. Moreover, IAA exposure significantly decreased estradiol levels (500mg/L) in serum compared to control. This study identified key candidate genes and pathways involved in IAA toxicity that could help to further understand the molecular mechanisms of IAA toxicity in ovarian follicles.
Project description:Indole-3-acetic acid (IAA), knows as common plant hormone, is one of the most distributed indole derivatives in the environment. A novel strain, which was able to use IAA as sole source of carbon and nitrogen, was isolated from farm soil, identified and classified as Pseudomonas composti LY1 based on 16S rRNA sequence and genome analysis. The optimal growth conditions for LY1 with IAA are characterized. Proteome profile of strain LY1 to IAA and citrate were analyzed and compared using label free strategy with LC-MS/MS.
Project description:Bolting is a key process in the growth and development of lettuce (Lactuca sativa L.). High temperature can induce earlier bolting which decreases in both quality and production of lettuce. However, knowledge underlying lettuce bolting is still lacking. To better understand the molecular basis of bolting, a comparative proteomics analysis was conducted on lettuce stems in the bolting period induced by high temperature (33 °C) compared with a control (20 °C) using iTRAQ-based proteomics, phenotypic measures, and biological verifications. High temperature induced lettuce bolting, while control temperature did not. Of the 6656 proteins identified, 758 proteins significantly altered their expression level induced by high-temperature relative to the control, of which 409 were up-regulated and 349 down-regulated. Proteins with abundance level change were mainly involved in photosynthesis, carbohydrate metabolism, stress response, hormone synthesis, and signal transduction. These differential proteins were mainly enriched in pathways associated with photosynthesis and tryptophan metabolism involving in auxin (IAA) biosynthesis. Among the differentially expressed proteins associated with photosynthesis and tryptophan metabolism were up-regulated. Moreover, in gibberellin (GA) biosynthesis pathway, 10 of main enzymes of P450 were up-regulated. Proteins related to SAUR and GRP, implicated in IAA and GA signal transduction were up-regulated, and the phosphorylation and ubiquitination related proteins regulating IAA and GA signal transduction were also induced. These findings indicate that a high temperature enhances the function of photosynthesis, IAA and GA synthesis and signal transduction to promote the process of bolting, which is in line with the physiology and transcription levels of IAA and GA metabolism. Our data provide a first comprehensive dataset for gaining novel understanding of the molecular basis underlying lettuce bolting induced by high temperature. It is potentially important for further functional analysis and genetic manipulation for molecular breeding to breed new cultivar of lettuce to restrain early bolting, which is vital for improving vegetable quality.
Project description:Grain filling in maize (Zea mays L.) is intricately linked to cell development, involving the regulation of genes responsible for the biosynthesis of storage reserves (starch, proteins, and lipids) and phytohormones. However, the regulatory network coordinating these biological functions remains unclear. In this study, we identified 1,744 high-confidence target genes co-regulated by the transcription factors (TFs) ZmNAC128 and ZmNAC130 (ZmNAC128/130) through chromatin immunoprecipitation sequencing coupled with RNA-seq analysis in the zmnac128/130 loss-of-function mutants. We further constructed a hierarchical regulatory network using DNA affinity purification sequencing analysis of downstream TFs regulated by ZmNAC128/130. In addition to target genes involved in the biosynthesis of starch and zeins, we discovered novel target genes of ZmNAC128/130 involved in the biosynthesis of lipids and indole-3-acetic acid (IAA). Consistently, the number of oil bodies, as well as the contents of triacylglycerol and IAA were significantly reduced in zmnac128/130. The hierarchical regulatory network centered by ZmNAC128/130 revealed a significant overlap between the direct target genes of ZmNAC128/130 and their downstream TFs, particularly in regulating the biosynthesis of storage reserves and IAA. Our results indicated that the biosynthesis of storage reserves and IAA is coordinated by a multi-TFs hierarchical regulatory network in maize endosperm.
Project description:Two major genetic pathways leading to colorectal carcinoma can well be distinguished; the ‘suppressor pathway’, which is characterized by inactivation of tumor-suppressor genes and the ‘mutator pathway’, which is characterized by microsatellite instability. The purpose of this study is to explore a third putative pathway; microsatellite and chromosome stable colorectal cancer where an alternative cancer-causative mechanism might play a role.