The article by Dennis A. Bazylinski and Richard B. Frankel provides an overview of the progress in understanding the molecular, biochemical, chemical, and genetic bases of magnetosome formation in magnetotactic bacteria. Magnetotactic bacteria are a group of motile, mostly aquatic prokaryotes that swim along geomagnetic field lines. They synthesize unique intracellular structures called magnetosomes, which consist of a magnetic mineral crystal surrounded by a lipid bilayer membrane. The formation of magnetosomes is under precise biological control and involves a mineralization process known as biologically controlled mineralization. Magnetotactic bacteria typically produce either iron oxide (magnetite, Fe3O4) or iron sulfide (greigite, Fe3S4) magnetosomes. The mineral composition of magnetosomes is strictly controlled, and the size and shape of the crystals are consistent within cells. The arrangement of magnetosomes in chains allows for the alignment of their magnetic dipole moments, enabling the bacteria to swim along geomagnetic field lines. The synthesis of magnetosomes involves several steps, including the formation of magnetosome vesicles, iron uptake by the cell, iron transport into the vesicle, and controlled biomineralization of Fe3O4 or Fe3S4 within the vesicle. Iron uptake is facilitated by proteins such as MagA, which functions as an H+/Fe(II) antiporter. The magnetosome membrane vesicle is thought to originate from the cytoplasmic membrane and is invaginated to form the vesicle. The article also discusses the role of various proteins and genes in magnetosome formation, including Mms proteins, MamB and MamM, and TPR proteins. These proteins play crucial roles in iron transport, crystal growth, and the overall process of magnetosome synthesis. Additionally, the presence of genomic islands containing genes related to magnetosome synthesis suggests that horizontal gene transfer may contribute to the evolution and loss of this trait in different bacteria.The article by Dennis A. Bazylinski and Richard B. Frankel provides an overview of the progress in understanding the molecular, biochemical, chemical, and genetic bases of magnetosome formation in magnetotactic bacteria. Magnetotactic bacteria are a group of motile, mostly aquatic prokaryotes that swim along geomagnetic field lines. They synthesize unique intracellular structures called magnetosomes, which consist of a magnetic mineral crystal surrounded by a lipid bilayer membrane. The formation of magnetosomes is under precise biological control and involves a mineralization process known as biologically controlled mineralization. Magnetotactic bacteria typically produce either iron oxide (magnetite, Fe3O4) or iron sulfide (greigite, Fe3S4) magnetosomes. The mineral composition of magnetosomes is strictly controlled, and the size and shape of the crystals are consistent within cells. The arrangement of magnetosomes in chains allows for the alignment of their magnetic dipole moments, enabling the bacteria to swim along geomagnetic field lines. The synthesis of magnetosomes involves several steps, including the formation of magnetosome vesicles, iron uptake by the cell, iron transport into the vesicle, and controlled biomineralization of Fe3O4 or Fe3S4 within the vesicle. Iron uptake is facilitated by proteins such as MagA, which functions as an H+/Fe(II) antiporter. The magnetosome membrane vesicle is thought to originate from the cytoplasmic membrane and is invaginated to form the vesicle. The article also discusses the role of various proteins and genes in magnetosome formation, including Mms proteins, MamB and MamM, and TPR proteins. These proteins play crucial roles in iron transport, crystal growth, and the overall process of magnetosome synthesis. Additionally, the presence of genomic islands containing genes related to magnetosome synthesis suggests that horizontal gene transfer may contribute to the evolution and loss of this trait in different bacteria.