85 research outputs found
The south green rice genome hub
We have developed the Rice Genome Hub (https://rice-genome-hub.southgreen.fr), an integrative genome information system that allows centralized access to genomics and genetics data, and analytical tools to facilitate translational and applied research in rice.Rice is the world's most consumed staple food, especially in Asia. It is also one of the most cultivated crop with maize and wheat. The Hub currently contains seven annotated genome sequences ofOryza sativa(Asian rice), and one ofOryza glaberrima(African rice).The hub is built using the the Content Management System Drupal with the Tripal module that interacts with the Chado database. We opted for GMOD components that are open source, modular, portable and benefiting from a large community support in which we have been involved. The Hub interface provides several functionalities (Blast, DotPlots, Gene Search, JBrowse, Primer Blaster, Primer Designer) to make it easy for querying, visualizing and downloading research data.We also plugged in-house tools developed by the South Green bioinformatics platform such as SNiPlay (detection and analyses of SNPs),Gigwa (filtering on genomic variations), daTALbase (exploration of data related to Xanthomonas TAL effectors), and DiffExDB (differential expression analysis)
Rice Yellow Mottle Virus stress responsive genes from susceptible and tolerant rice genotypes
<p>Abstract</p> <p>Background</p> <p>The effects of viral infection involve concomitant plant gene variations and cellular changes. A simple system is required to assess the complexity of host responses to viral infection. The genome of the Rice yellow mottle virus (RYMV) is a single-stranded RNA with a simple organisation. It is the most well-known monocotyledon virus model. Several studies on its biology, structure and phylogeography have provided a suitable background for further genetic studies. 12 rice chromosome sequences are now available and provide strong support for genomic studies, particularly physical mapping and gene identification.</p> <p>Results</p> <p>The present data, obtained through the cDNA-AFLP technique, demonstrate differential responses to RYMV of two different rice cultivars, i.e. susceptible IR64 (<it>Oryza sativa indica</it>), and partially resistant Azucena (<it>O. s. japonica</it>). This RNA profiling provides a new original dataset that will enable us to gain greater insight into the RYMV/rice interaction and the specificity of the host response. Using the SIM4 subroutine, we took the intron/exon structure of the gene into account and mapped 281 RYMV stress responsive (RSR) transcripts on 12 rice chromosomes corresponding to 234 RSR genes. We also mapped previously identified deregulated proteins and genes involved in partial resistance and thus constructed the first global physical map of the RYMV/rice interaction. RSR transcripts on rice chromosomes 4 and 10 were found to be not randomly distributed. Seven genes were identified in the susceptible and partially resistant cultivars, and transcripts were colocalized for these seven genes in both cultivars. During virus infection, many concomitant plant gene expression changes may be associated with host changes caused by the infection process, general stress or defence responses. We noted that some genes (e.g. ABC transporters) were regulated throughout the kinetics of infection and differentiated susceptible and partially resistant hosts.</p> <p>Conclusion</p> <p>We enhanced the first RYMV/rice interaction map by combining information from the present study and previous studies on proteins and ESTs regulated during RYMV infection, thus providing a more comprehensive view on genes related to plant responses. This combined map provides a new tool for exploring molecular mechanisms underlying the RYMV/rice interaction.</p
Ancestral synteny shared between distantly-related plant species from the asterid (Coffea canephora and Solanum Sp.) and rosid (Vitis vinifera) clades
Background: Coffee trees (Rubiaceae) and tomato (Solanaceae) belong to the Asterid clade, while grapevine (Vitaceae) belongs to the Rosid clade. Coffee and tomato separated from grapevine 125 million years ago, while coffee and tomato diverged 83-89 million years ago. These long periods of divergent evolution should have permitted the genomes to reorganize significantly. So far, very few comparative mappings have been performed between very distantly related species belonging to different clades. We report the first multiple comparison between species from Asterid and Rosid clades, to examine both macro-and microsynteny relationships. Results: Thanks to a set of 867 COSII markers, macrosynteny was detected between coffee, tomato and grapevine. While coffee and tomato genomes share 318 orthologous markers and 27 conserved syntenic segments (CSSs), coffee and grapevine also share a similar number of syntenic markers and CSSs: 299 and 29 respectively. Despite large genome macrostructure reorganization, several large chromosome segments showed outstanding macrosynteny shedding new insights into chromosome evolution between Asterids and Rosids. We also analyzed a sequence of 174 kb containing the ovate gene, conserved in a syntenic block between coffee, tomato and grapevine that showed a high-level of microstructure conservation. A higher level of conservation was observed between coffee and grapevine, both woody and long life-cycle plants, than between coffee and tomato. Out of 16 coffee genes of this syntenic segment, 7 and 14 showed complete synteny between coffee and tomato or grapevine, respectively. Conclusions: These results show that significant conservation is found between distantly related species from the Asterid (Coffea canephora and Solanum sp.) and Rosid (Vitis vinifera) clades, at the genome macrostructure and microstructure levels. At the ovate locus, conservation did not decline in relation to increasing phylogenetic distance, suggesting that the time factor alone does not explain divergences. Our results are considerably useful for syntenic studies between supposedly remote species for the isolation of important genes for agronomy
Site-Specific Insertion Polymorphism of the MITE Alex-1 in the Genus Coffea Suggests Interspecific Gene Flow
Miniature Inverted-repeat Transposable Elements (MITEs) are small nonautonomous class-II transposable elements distributed throughout eukaryotic genomes. We identified a novel family of MITEs (named Alex) in the Coffea canephora genome often associated with expressed sequences. The Alex-1 element is inserted in an intron of a gene at the CcEIN4 locus. Its mobility was demonstrated by sequencing the insertion site in C. canephora accessions and Coffea species. Analysis of the insertion polymorphism of Alex-1 at this locus in Coffea species and in C. canephora showed that there was no relationship between the geographical distribution of the species, their phylogenetic relationships, and insertion polymorphism. The intraspecific distribution of C. canephora revealed an original situation within the E diversity group. These results suggest possibly greater gene flow between species than previously thought. This MITE family will enable the study of the C. canephora genome evolution, phylogenetic relationships, and possible gene flows within the Coffea genus
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