title: PCR analysis of expR gene regulating biosynthesis of exopolysaccharides in Sinorhizobium meliloti.
abstract: Exopolysaccharide (EPS) production by the rhizobacterium Sinorhizobium meliloti is essential for root nodule formation on its legume host (alfalfa), and for establishment of a nitrogen-fixing symbiosis between the two partners. Production of EPS II (galactoglucan) by certain S. meliloti strains results in a mucoid colony phenotype. Other strains that are unable to produce EPS II display a dry phenotype, due to the presence of an insertion element in the gene expR, a key regulator involved in many important cellular processes, including production of low-molecular-weight EPS II. We describe a series of three programmed undergraduate biochemistry laboratory classes teaching PCR and electrophoresis procedures to detect non-functional expR loci in S. meliloti.
authors.affiliation: Departamento de Biología Molecular, Universidad Nacional de Río Cuarto, Córdoba, Argentina.
authors.forename: Fernando G
authors.initials: FG
authors.lastname: Sorroche
authors.forename: Walter
authors.initials: W
authors.lastname: Giordano
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D001671:Biochemistry / Q000193:education*; D003479:Curriculum; D004587:Electrophoresis, Agar Gel; D015964:Gene Expression Regulation, Bacterial; D016133:Polymerase Chain Reaction; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D053038:Quorum Sensing; D016962:Sinorhizobium meliloti / Q000235:genetics* / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D011135:Polysaccharides, Bacterial; D015534:Trans-Activators