title: A genetic strategy for probing the functional diversity of magnetosome formation.
abstract: Model genetic systems are invaluable, but limit us to understanding only a few organisms in detail, missing the variations in biological processes that are performed by related organisms. One such diverse process is the formation of magnetosome organelles by magnetotactic bacteria. Studies of model magnetotactic α-proteobacteria have demonstrated that magnetosomes are cubo-octahedral magnetite crystals that are synthesized within pre-existing membrane compartments derived from the inner membrane and orchestrated by a specific set of genes encoded within a genomic island. However, this model cannot explain all magnetosome formation, which is phenotypically and genetically diverse. For example, Desulfovibrio magneticus RS-1, a δ-proteobacterium for which we lack genetic tools, produces tooth-shaped magnetite crystals that may or may not be encased by a membrane with a magnetosome gene island that diverges significantly from those of the α-proteobacteria. To probe the functional diversity of magnetosome formation, we used modern sequencing technology to identify hits in RS-1 mutated with UV or chemical mutagens. We isolated and characterized mutant alleles of 10 magnetosome genes in RS-1, 7 of which are not found in the α-proteobacterial models. These findings have implications for our understanding of magnetosome formation in general and demonstrate the feasibility of applying a modern genetic approach to an organism for which classic genetic tools are not available.
authors.affiliation: Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America.
authors.forename: Lilah
authors.initials: L
authors.lastname: Rahn-Lee
authors.affiliation: Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America.
authors.forename: Meghan E
authors.initials: ME
authors.lastname: Byrne
authors.affiliation: Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America.
authors.forename: Manjing
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America; Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, United States of America.
authors.forename: David
authors.initials: D
authors.lastname: Le Sage
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America; Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, United States of America; Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: David R
authors.initials: DR
authors.lastname: Glenn
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Timothy
authors.initials: T
authors.lastname: Milbourne
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts, United States of America; Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, United States of America; Center for Brain Science, Harvard University, Cambridge, Massachusetts, United States of America.
authors.forename: Ronald L
authors.initials: RL
authors.lastname: Walsworth
authors.affiliation: Facility for Electron Microscopy Research, McGill University, Montreal, Quebec, Canada; Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada; Department of Earth and Planetary Sciences, McGill University, Montreal, Quebec, Canada.
authors.forename: Hojatollah
authors.initials: H
authors.lastname: Vali
authors.affiliation: Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, California, United States of America.
authors.forename: Arash
authors.initials: A
authors.lastname: Komeili
mesh_terms: D000483:Alleles; D003901:Desulfovibrio / Q000235:genetics* / Q000378:metabolism; D052203:Ferrosoferric Oxide / Q000378:metabolism; D044404:Genomic Islands; D007501:Iron / Q000378:metabolism; D055944:Magnetosomes / Q000235:genetics*; D005810:Multigene Family; D009154:Mutation; D015388:Organelles / Q000235:genetics*
chemical_list: D007501:Iron; D052203:Ferrosoferric Oxide