title: Genetic diversity within populations of cyanobacteria assessed by analysis of single filaments.
abstract: We have developed a technique for determining the genetic structure of populations of filamentous cyanobacteria. The sequence diversity at specific gene loci is first characterised in a range of clonal cultures; subsequent analysis involves individual trichomes collected directly from natural populations. This technique has been used to examine the population genetic structure of Nodularia in the Baltic Sea and Planktothrix in Lake Zürich. For Nodularia, studies utilising four polymorphic loci reveal that even though there is a degree of linkage disequilibrium, horizontal transfer of genetic information has been sufficient to generate many of the possible allelic combinations. Analyses reveal both spatial and temporal variation in population genetic structure. Other studies of both Nodularia and Planktothrir have shown a correlation between particular alleles at the gvpC locus and the critical pressure of the gas vesicles that accumulate within the cell. We are now investigating how the natural selection of different gas vesicle phenotypes, imposed by changes in the depth of the upper mixed layer of the water column, affects the relative success of individual cyanobacteria possessing different gvpC alleles.
authors.affiliation: School of Biological Sciences, University of Bristol, UK.
authors.forename: Paul K
authors.initials: PK
authors.lastname: Hayes
authors.forename: G L A
authors.initials: GL
authors.lastname: Barker
authors.forename: J
authors.initials: J
authors.lastname: Batley
authors.forename: S J
authors.initials: SJ
authors.lastname: Beard
authors.forename: B A
authors.initials: BA
authors.lastname: Handley
authors.forename: P
authors.initials: P
authors.lastname: Vacharapiyasophon
authors.forename: A E
authors.initials: AE
authors.lastname: Walsby
mesh_terms: D019843:Archaeal Proteins / Q000235:genetics*; D001454:Baltic States; D000458:Cyanobacteria / Q000235:genetics*; D005618:Fresh Water / Q000382:microbiology; D014644:Genetic Variation; D005828:Genetics, Population; D008565:Membrane Proteins / Q000235:genetics*; D016133:Polymerase Chain Reaction; D011506:Proteins; D012623:Seawater / Q000382:microbiology; D013557:Switzerland
chemical_list: D019843:Archaeal Proteins; D008565:Membrane Proteins; D011506:Proteins; C038524:gas vesicle protein