title: Single-organelle tracking by two-photon conversion.
abstract: Spatial and temporal information about intracellular objects and their dynamics within a living cell are essential for dynamic analysis of such objects in cell biology. A specific intracellular object can be discriminated by photoactivatable fluorescent proteins that exhibit pronounced light-induced spectral changes. Here, we report on selective labeling and tracking of a single organelle by using two-photon conversion of a photoconvertible fluorescent protein with near-infrared femtosecond laser pulses. We performed selective labeling of a single mitochondrion in a living tobacco BY-2 cell using two-photon photoconversion of Kaede. Using this technique, we demonstrated that, in plants, the directed movement of individual mitochondria along the cytoskeletons was mediated by actin filaments, whereas microtubules were not required for the movement of mitochondria. This single-organelle labeling technique enabled us to track the dynamics of a single organelle, revealing the mechanisms involved in organelle dynamics. The technique has potential application in direct tracking of selective cellular and intracellular structures.
authors.forename: Wataru
authors.initials: W
authors.lastname: Watanabe
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shimada
authors.forename: Sachihiro
authors.initials: S
authors.lastname: Matsunaga
authors.forename: Daisuke
authors.initials: D
authors.lastname: Kurihara
authors.forename: Kiichi
authors.initials: K
authors.lastname: Fukui
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Shin-Ichi Arimura
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Tsutsumi
authors.forename: Keisuke
authors.initials: K
authors.lastname: Isobe
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Itoh