Medicago truncatula Tnt1 Insertion Mutagenesis Database
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Welcome to the M. truncatula Mutagenesis Database


Background

Legumes are second only to grasses in their worldwide economic importance. Apart from their direct use as an excellent source of dietary proteins for human consumption and their critical importance as pastures and forage crops in animal and dairy production, legumes play a pivotal role in maintaining our ecosystem by fixing atmospheric nitrogen in symbiotic association with soil bacteria of the genus Rhizobium. Understanding legume molecular genetics is, thus, vital to facilitate breeding of important grain and forage legumes.

M. truncatula has been selected as a model plant to study biological processes that are unique and pertinent to legumes, and that cannot easily be studied in Arabidopsis. Several genomic tools and resources for M. truncatula are currently available and a genome sequencing project is ongoing. M. truncatula currently lacks an extensive collection of, cloning-friendly, insertion mutants that are vital to study gene function. With the funding from the Noble Foundation we have initiated a project to do a near-saturation mutagenesis of Medicago truncatula using a tobacco retrotransposon Tnt1. Contingent upon funding, approximately 15,000 Tnt1 tagged M. truncatula lines, with an average of 25 insertions per line, will be produced during the next 5 years. Similar mutant lines that are currently being developed by the European groups will be integrated with the proposed collection to obtain approximately 21,000 insertion mutant lines at 90% saturation level. In addition to developing the mutant lines a publicly available flanking sequence database with more than 10,000 sequences will be developed.

In collaboration with interested colleagues from University of York, UK; CNRS, France; University of North Texas, Denton and the Noble Foundation we have recently screened the first 1557 lines for visible phenotypes in the R1 generation. The outcomes of this screening were very successful and we identified many mutants for every phenotype we looked for. We identified approximately 28% visible mutants in at least 25 distinct classes. Some examples of representative mutants including supernodulating, non nodulating, non nitrogen fixing, late and early flowering, dwarf, altered anthocyanin producing, light green, albino, transformed floral organs, and singlet leaves with cauliflower-like reproductive tissue are shown on this website.

About This Database

Currently the database hosts images of mutants that showed significant phenotypes, organized according to gene line IDs. Functionality of the website is expanding and the mutant records will be updates periodically.

To browse a partial list of current mutants, please use the navigation menu on the top of this page, or click here. On the mutant list page, you may search for particular mutants by their IDs.

A full collection of the corresponding insertion sequences are being separately managed with the PLAN (Personal BLAST Navigator) system. Currently, PLAN hosts the identification of of each insertion sequence through BLAST searchs against NCBI NT (non-redundant nucleic tide), NCBI NR (non-redundant protein), TIGR MTGI v8 (Mt Gene Index), IMGAG Mt BAC sequences, and IMGAG prodicted Mt genes. Inside of the PLAN system, you may search according to a target accession ID (such as a BAC sequence ID, or a gene ID) or descriptional keyword (such as "transcription factor").

Seamless integration of PLAN's sequence management functions into this mutant database is under consideration.



Copyright © 2006 The Samuel Roberts Noble Foundation