Browsing by Author "Moyano, Tomas C."

Now showing 1 - 7 of 7
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    Dynamic changes in mRNA nucleocytoplasmic localization in the nitrate response of Arabidopsis roots
    (2024) Fonseca, Alejandro; Riveras, Eleodoro; Moyano, Tomas C.; Alvarez, Jose M.; Rosa, Stefanie; Gutierrez, Rodrigo A.
    Nitrate is a nutrient and signal that regulates gene expression. The nitrate response has been extensively characterized at the organism, organ, and cell-type-specific levels, but intracellular mRNA dynamics remain unexplored. To characterize nuclear and cytoplasmic transcriptome dynamics in response to nitrate, we performed a time-course expression analysis after nitrate treatment in isolated nuclei, cytoplasm, and whole roots. We identified 402 differentially localized transcripts (DLTs) in response to nitrate treatment. Induced DLT genes showed rapid and transient recruitment of the RNA polymerase II, together with an increase in the mRNA turnover rates. DLTs code for genes involved in metabolic processes, localization, and response to stimulus indicating DLTs include genes with relevant functions for the nitrate response that have not been previously identified. Using single-molecule RNA FISH, we observed early nuclear accumulation of the NITRATE REDUCTASE 1 (NIA1) transcripts in their transcription sites. We found that transcription of NIA1, a gene showing delayed cytoplasmic accumulation, is rapidly and transiently activated; however, its transcripts become unstable when they reach the cytoplasm. Our study reveals the dynamic localization of mRNAs between the nucleus and cytoplasm as an emerging feature in the temporal control of gene expression in response to nitrate treatment in Arabidopsis roots.
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    Genomic Footprinting Analyses from DNase-seq Data to Construct Gene Regulatory Networks
    (HUMANA PRESS INC, 2021) Moyano, Tomas C.; Gutierrez, Rodrigo A.; Alvarez, Jose M.; Mukhtar, S
    Chromatin accessibility is directly linked with transcription in eukaryotes. Accessible regions associated with regulatory proteins are highly sensitive to DNase I digestion and are termed DNase I hypersensitive sites (DHSs). DHSs can be identified by DNase I digestion, followed by high-throughput DNA sequencing (DNase-seq). The single-base-pair resolution digestion patterns from DNase-seq allows identifying transcription factor (TF) footprints of local DNA protection that predict TF-DNA binding. The identification of differential footprinting between two conditions allows mapping relevant TF regulatory interactions. Here, we provide step-by-step instructions to build gene regulatory networks from DNase-seq data. Our pipeline includes steps for DHSs calling, identification of differential TF footprints between treatment and control conditions, and construction of gene regulatory networks. Even though the data we used in this example was obtained from Arabidopsis thaliana, the workflow developed in this guide can be adapted to work with DNase-seq data from any organism with a sequenced genome.
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    Integrated RNA-seq and sRNA-seq analysis identifies novel nitrate-responsive genes in Arabidopsis thaliana roots
    (2013) Vidal, Elena A.; Moyano, Tomas C.; Krouk, Gabriel; Katari, Manpreet S.; Tanurdzic, Milos; McCombie, W. Richard; Coruzzi, Gloria M.; Gutierrez, Rodrigo A.
    Background: Nitrate and other nitrogen metabolites can act as signals that regulate global gene expression in plants. Adaptive changes in plant morphology and physiology triggered by changes in nitrate availability are partly explained by these changes in gene expression. Despite several genome-wide efforts to identify nitrate-regulated genes, no comprehensive study of the Arabidopsis root transcriptome under contrasting nitrate conditions has been carried out.
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    Spatiotemporal analysis identifies ABF2 and ABF3 as key hubs of endodermal response to nitrate
    (2022) Contreras-Lopez, Orlando; Vidal, Elena A.; Riveras, Eleodoro; Alvarez, Jose M.; Moyano, Tomas C.; Sparks, Erin E.; Medina, Joaquin; Pasquino, Angelo; Benfey, Philip N.; Coruzzi, Gloria M.; Gutierrez, Rodrigo A.
    Nitrate is a nutrient and a potent signal that impacts global gene expression in plants. However, the regulatory factors controlling temporal and cell type-specific nitrate responses remain largely unknown. We assayed nitrate-responsive transcriptome changes in five major root cell types of the Arabidopsis thaliana root as a function of time. We found that gene-expression response to nitrate is dynamic and highly localized and predicted cell type- specific transcription factor (TF)-target interactions. Among cell types, the endodermis stands out as having the largest and most connected nitrate-regulatory gene network. ABF2 and ABF3 are major hubs for transcriptional responses in the endodermis cell layer. We experimentally validated TF-target interactions for ABF2 and ABF3 by chromatin immunoprecipitation followed by sequenc-ing and a cell-based system to detect TF regulation genome-wide. Validated targets of ABF2 and ABF3 account for more than 50% of the nitrate-responsive transcriptome in the endodermis. Moreover, ABF2 and ABF3 are involved in nitrate-induced lateral root growth. Our approach offers an unprecedented spatiotemporal resolution of the root response to nitrate and identifies important compo-nents of cell-specific gene regulatory networks.
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    Systems analysis of transcriptome data provides new hypotheses about Arabidopsis root response to nitrate treatments
    (2014) Canales, Javier; Moyano, Tomas C.; Villarroel, Eva; Gutierrez, Rodrigo A.
    Nitrogen (N) is an essential macronutrient for plant growth and development. Plants adapt to changes in N availability partly by changes in global gene expression. We integrated publicly available root microarray data under contrasting nitrate conditions to identify new genes and functions important for adaptive nitrate responses in Arabidopsis thaliana roots. Overall, more than 2000 genes exhibited changes in expression in response to nitrate treatments in Arabidopsis thaliana root organs. Global regulation of gene expression by nitrate depends largely on the experimental context. However, despite significant differences from experiment to experiment in the identity of regulated genes, there is a robust nitrate response of specific biological functions. Integrative gene network analysis uncovered relationships between nitrate-responsive genes and 11 highly co-expressed gene clusters (modules). Four of these gene network modules have robust nitrate responsive functions such as transport, signaling, and metabolism. Network analysis hypothesized G2-like transcription factors are key regulatory factors controlling transport and signaling functions. Our meta-analysis highlights the role of biological processes not studied before in the context of the nitrate response such as root hair development and provides testable hypothesis to advance our understanding of nitrate responses in plants.
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    The Botrytis cinerea Gene Expression Browser
    (2023) Perez-Lara, Gabriel; Moyano, Tomas C.; Vega, Andrea; Larrondo, Luis F.; Polanco, Ruben; Alvarez, Jose M.; Aguayo, Daniel; Canessa, Paulo
    For comprehensive gene expression analyses of the phytopathogenic fungus Botrytis cinerea, which infects a number of plant taxa and is a cause of substantial agricultural losses worldwide, we developed BEB, a web-based B. cinerea gene Expression Browser. This computationally inexpensive web-based application and its associated database contain manually curated RNA-Seq data for B. cinerea. BEB enables expression analyses of genes of interest under different culture conditions by providing publication-ready heatmaps depicting transcript levels, without requiring advanced computational skills. BEB also provides details of each experiment and user-defined gene expression clustering and visualization options. If needed, tables of gene expression values can be downloaded for further exploration, including, for instance, the determination of differentially expressed genes. The BEB implementation is based on open-source computational technologies that can be deployed for other organisms. In this case, the new implementation will be limited only by the number of transcriptomic experiments that are incorporated into the platform. To demonstrate the usability and value of BEB, we analyzed gene expression patterns across different conditions, with a focus on secondary metabolite gene clusters, chromosome-wide gene expression, previously described virulence factors, and reference genes, providing the first comprehensive expression overview of these groups of genes in this relevant fungal phytopathogen. We expect this tool to be broadly useful in B. cinerea research, providing a basis for comparative transcriptomics and candidate gene identification for functional assays.
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    Whole Genome Sequence, Variant Discovery and Annotation in Mapuche-Huilliche Native South Americans
    (2019) Vidal, Elena A.; Moyano, Tomas C.; Bustos, Bernabe, I; Perez-Palma, Eduardo; Moraga, Carol; Riveras Hernández, Eleodoro Javier; Pérez-Palma E.; Moraga, C.; Montecinos, A.; Azócar, L.; Soto, D. C.; Di Genova, A.; Puschel Illanes, Klaus; Nürnberg, P.; Buch, S.; Hampe, J; Allende, M. L.; Cambiazo, V.; González, M.; Hodar, C.; Montecino, M.; Muñoz-Espinoza, C.; Orellana, A.; Reyes-Jara, A.; Travisany, D.; Vizoso, P.; Moraga, M.; Eyheramendy Duerr, Susana; Maass, A.; Ferrari, G. V. de; Miquel P., Juan Francisco; Gutiérrez Ilabaca, Rodrigo Antonio