title: Development of a lab-made microarray for analyzing the genetic diversity of nitrogen fixing symbionts Sinorhizobium meliloti and Sinorhizobium medicae.
abstract: Some bacterial species, like nitrogen-fixing Sinorhizobium that interact with Medicago plants, are prone to frequent horizontal gene transfers. Investigation of their genetic structure requires to study polymorphism patterns at many loci. Although DNA microarrays represent a method of choice for high throughput analysis of polymorphisms, this technology yet remains an expensive and heavy approach, thus depriving most of research groups from this powerful tool. In an attempt to overcome this limitation, we have developed a simple genotyping procedure by DNA microarrays, and have evaluated its ability to characterize a Sinorhizobium population. Thirty 18- to 24-mer oligonucleotide probes were designed to target the most frequent mutations in three polymorphic loci of Sinorhizobium meliloti and S. medicae. Probe hybridization efficiency was compared on two spotting surfaces: nylon membranes and epoxy-coated glass slides. Epoxy-coated glass slides revealed more sensitive than nylon membranes and allowed discrimination of single mismatches. Using this procedure, an uncharacterized population consisting of 33 S. meliloti/S. medicae isolates was successfully genotyped.
authors.affiliation: Laboratoire des Symbioses Tropicales et Méditerranéennes, UMR113 IRD/INRA/CIRAD/UM2/Agro-M, Campus International de Baillarguet, Montpellier F34398, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Bailly
authors.forename: Gilles
authors.initials: G
authors.lastname: Béna
authors.forename: Vanina
authors.initials: V
authors.lastname: Lenief
authors.forename: Philippe
authors.initials: P
authors.lastname: de Lajudie
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Avarre
mesh_terms: D014644:Genetic Variation; D046228:Microarray Analysis / Q000379:methods*; D009586:Nitrogen Fixation / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D020579:Sinorhizobium / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D016962:Sinorhizobium meliloti / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D013559:Symbiosis