Trava Home

Welcome to TraVA, the database of gene expression profiles in Arabidopsis thaliana based on RNA-seq analysis.

This project is a collaborative effort of scientists from Institute for information transmission problems and Lomonosov Moscow state university(Laboratory of evolutionary genomics and Department of genetics). Currently, profiles of 25706 protein-coding genes in 79 samples (complete list of samples with their detailed description can be found here) are presented.


Publications.

1. Anna Klepikova, Maria Logacheva, Sergey Dmitriev and Aleksey Penin RNA-seq analysis of an apical meristem time series reveals a critical point in Arabidopsis thaliana flower initiation. BMC Genomics 2015 16:466

Abstract

Background

Floral transition is a critical event in the life cycle of a flowering plant as it determines its reproductive success. Despite extensive studies of specific genes that regulate this process, the global changes in transcript expression profiles at the point when a vegetative meristem transitions into an inflorescence have not been reported. We analyzed gene expression during Arabidopsis thaliana meristem development under long day conditions from day 7 to 16 after germination in one-day increments.

Results

The dynamics of the expression of the main flowering regulators was consistent with previous reports: notably, the expression of FLOWERING LOCUS C (FLC) decreased over the course of the time series while expression of LEAFY (LFY) increased. This analysis revealed a developmental time point between 10 and 12 days after germination where FLC expression had decreased but LFY expression had not yet increased, which was characterized by a peak in the number of differentially expressed genes. Gene Ontology (GO) enrichment analysis of these genes identified an overrepresentation of genes related to the cell cycle.

Conclusions

We discovered an unprecedented burst of differential expression of cell cycle related genes at one particular point during transition to flowering. We suggest that acceleration of rate of the divisions and partial cell cycling synchronization takes place at this point.


2. Anna Klepikova, Artem Kasianov, Evgeny Gerasimov, Maria Logacheva and Aleksey Penin A High Resolution Map of the Arabidopsis thaliana Developmental Transcriptome Based on RNA-seq Profiling.

Summary

Arabidopsis thaliana is a long established model species for plant molecular biology, genetics and genomics, and studies of A.thaliana gene function provide the basis for formulating hypotheses and designing experiments involving other plants, including economically important species. A comprehensive understanding of the A.thaliana genome and a detailed and accurate understanding of the expression of its associated genes is therefore of great importance for both fundamental research and practical applications. Such goal is reliant on the development of new genetic and genomic resources, involving new methods of data acquisition and analysis. We present here the genome-wide analysis of A.thaliana gene expression profiles across different organs and developmental stages using high-throughput transcriptome sequencing. The expression of 25,706 protein-coding genes, as well as their stability and their spatiotemporal specificity, was assessed in 79 organs and developmental stages. A search for alternative splicing events identified 37,873 previously unreported splice junctions, approximately 30% of occurred in intergenic regions. These potentially represent novel spliced genes that are not included in the TAIR10 database. These data are housed in an open-access web-based database, TraVA (Transcriptome Variation Analysis, http://travadb.org/), which allows visualization and analysis of gene expression profiles and differential gene expression between organs and developmental stages.


3. Artem S. Kasianov, Anna V. Klepikova, Ivan V. Kulakovskiy, Evgeny S. Gerasimov, Anna V. Fedotova, Elizaveta G. Besedina, Alexey S. Kondrashov, Maria D. Logacheva and Aleksey A. Penin High quality genome assembly of Capsella bursa-pastoris reveals asymmetry of regulatory elements at early stages of polyploid genome evolution.

Summary

Polyploidization and subsequent sub- and neofunctionalization of duplicated genes represent a major mechanism of plant genome evolution. Capsella bursa-pastoris, a widespread ruderal plant, is a recent allotetraploid, and, thus, is an ideal model organism for studying early changes following polyploidization. We constructed a high-quality assembly of C. bursa-pastoris genome and a transcriptome atlas covering a broad sample of organs and developmental stages (available online). We demonstrate that expression of homeologs is mostly symmetric between subgenomes and identify a set of homeolog pairs with discordant expression. Comparison of promoters within such pairs revealed emerging asymmetry of regulatory elements. Among them there are multiple binding sites for transcription factors controlling the regulation of photosynthesis and plant development by light (PIF3, HY5) and cold stress response (CBF). These results suggest that polyploidization in C. bursa-pastoris enhanced its plasticity of response to light and temperature and allowed substantial expansion of its distribution range.


4. Anna V. Klepikova, Ivan V. Kulakovskiy, Artem S. Kasianov, Maria D. Logacheva, Aleksey A. Penin An update to database TraVA: organ-specific cold stress response in Arabidopsis thaliana.

Abstract

Background

Transcriptome map is a powerful tool for a variety of biological studies; transcriptome maps that include different organs, tissues, cells and stages of development are currently available for at least 30 plants. Some of them include samples treated by environmental or biotic stresses. However, most studies explore only limited set of organs and developmental stages (leaves or seedlings). In order to provide broader view of organ-specific strategies of cold stress response we studied expression changes that follow exposure to cold (+ 4 °C) in different aerial parts of plant: cotyledons, hypocotyl, leaves, young flowers, mature flowers and seeds using RNA-seq.

Results

The results on differential expression in leaves are congruent with current knowledge on stress response pathways, in particular, the role of CBF genes. In other organs, both essence and dynamics of gene expression changes are different. We show the involvement of genes that are confined to narrow expression patterns in non-stress conditions into stress response. In particular, the genes that control cell wall modification in pollen, are activated in leaves. In seeds, predominant pattern is the change of lipid metabolism.

Conclusions

Stress response is highly organ-specific; different pathways are involved in this process in each type of organs. The results were integrated with previously published transcriptome map of Arabidopsis thaliana and used for an update of a public database TraVa: http://travadb.org/browse/Species=AthStress


5. Anna V. Klepikova, Artem S. Kasianov, Margarita A. Ezhova, Aleksey A. Penin, Maria D. Logacheva. Transcriptome atlas of Phalaenopsis equestris.

Abstract

The vast diversity of Orchidaceae together with sophisticated adaptations to pollinators and other unique features make this family an attractive model for evolutionary and functional studies. The sequenced genome of Phalaenopsis equestris facilitates Orchidaceae research. Here, we present an RNA-seq-based transcriptome map of P. equestris that covers 19 organs of the plant, including leaves, roots, floral organs and the shoot apical meristem. We demonstrated the high quality of the data and showed the similarity of the P. equestris transcriptome map with the gene expression atlases of other plants. The transcriptome map can be easily accessed through our database Transcriptome Variation Analysis (TraVA) for visualizing gene expression profiles. As an example of the application, we analyzed the expression of Phalaenopsis “orphan” genes–those that do not have recognizable similarity with the genes of other plants. We found that approximately half of these genes were not expressed; the ones that were expressed were predominantly expressed in reproductive structures.


6. Aleksey A. Penin, Artem S. Kasianov, Anna V. Klepikova, Ilya V. Kirov, Evgeny S. Gerasimov, Aleksey N. Fesenko, Maria D. Logacheva. High-resolution transcriptome atlas and improved genome assembly of common buckwheat, Fagopyrum esculentum.

Abstract

Common buckwheat (Fagopyrum esculentum) is an important non-cereal grain crop and a prospective component of functional food. Despite this, the genomic resources for this species and for the whole family Polygonaceae, to which it belongs, are scarce. Here, we report the assembly of the buckwheat genome using long-read technology and a high-resolution expression atlas including 46 organs and developmental stages. We found that the buckwheat genome has an extremely high content of transposable elements, including several classes of recently (0.5–1 Mya) multiplied TEs (“transposon burst”) and gradually accumulated TEs. The difference in TE content is a major factor contributing to the three-fold increase in the genome size of F. esculentum compared with its sister species F. tataricum. Moreover, we detected the differences in TE content between the wild ancestral subspecies F. esculentum ssp. ancestrale and buckwheat cultivars, suggesting that TE activity accompanied buckwheat domestication. Expression profiling allowed us to test a hypothesis about the genetic control of petaloidy of tepals in buckwheat. We showed that it is not mediated by B-class gene activity, in contrast to the prediction from the ABC model. Based on a survey of expression profiles and phylogenetic analysis, we identified the MYB family transcription factor gene tr_18111 as a potential candidate for the determination of conical cells in buckwheat petaloid tepals. The information on expression patterns has been integrated into the publicly available database TraVA: http://travadb.org/browse/Species=Fesc/. The improved genome assembly and transcriptomic resources will enable research on buckwheat, including practical applications.


7. Aleksey A Penin, Anna V Klepikova, Artem S Kasianov, Evgeny S Gerasimov, Maria D Logacheva. Comparative analysis of developmental transcriptome maps of Arabidopsis thaliana and Solanum lycopersicum.

Abstract

The knowledge of gene functions in model organisms is the starting point for the analysis of gene function in non-model species, including economically important ones. Usually, the assignment of gene functions is based on sequence similarity. In plants, due to a highly intricate gene landscape, this approach has some limitations. It is often impossible to directly match gene sets from one plant species to another species based only on their sequences. Thus, it is necessary to use additional information to identify functionally similar genes. Expression patterns have great potential to serve as a source of such information. An important prerequisite for the comparative analysis of transcriptomes is the existence of high-resolution expression maps consisting of comparable samples. Here, we present a transcriptome atlas of tomato (Solanum lycopersicum) consisting of 30 samples of different organs and developmental stages. The samples were selected in a way that allowed for side-by-side comparison with the Arabidopsis thaliana transcriptome map. Newly obtained data are integrated in the TraVA database and are available online, together with tools for their analysis. In this paper, we demonstrate the potential of comparing transcriptome maps for inferring shifts in the expression of paralogous genes.


8. Anna V. Klepikova, Artem S. Kasianov. An update to the TraVA database: time series of Capsella bursa-pastoris shoot apical meristems during transition to flowering.

Abstract

Transition to flowering is a crucial part of plant life directly affecting the fitness of a plant. Time series of transcriptomes is a useful tool for the investigation of process dynamics and can be used for the identification of novel genes and gene networks involved in the process. We present a detailed time series of polyploid Capsella bursa-pastoris shoot apical meristems created with RNA-seq. The time series covers transition to flowering and can be used for thorough analysis of the process. To make the data easy to access, we uploaded them in our database Transcriptome Variation Analysis (TraVA), which provides a convenient depiction of the gene expression profiles, the differential expression analysis between the homeologs and quick data extraction.

Dataset:http://travadb.org/browse/Species=Cbp2/