Organelle transport in melanophores analyzed by white light image correlation spectroscopy.
Intracellular transport of organelles, vesicles and proteins is crucial in all eukaryotic cells, and is accomplished by motor proteins that move along cytoskeletal filaments. A widely used model of intracellular transport is Xenopus laevis melanophores. These cells help the frog to change color by redistributing melanin-containing organelles in the cytoplasm. The high contrast of the pigment organelles permits changes in distribution to be observed by ordinary light microscopy; other intracellular transport systems often require fluorescence labeling. Here we have developed white light Image Correlation Spectroscopy (ICS) to monitor aggregation and dispersion of pigment. Hitherto in ICS, images of fluorescent particles from Confocal Laser Scanning Microscopy (CLSM) have been used to calculate autocorrelation functions from which the density can be obtained. In the present study we show that ICS can be modified to enable analysis of light-microscopy images; it can be used to monitor pigment aggregation and dispersion, and distinguish between different stimuli. This new approach makes ICS applicable not only to fluorescent but also to black-and-white images from light or electron microscopy, and is thus very versatile in different studies of movement of particles on the membrane or in the cytoplasm of cells without potentially harmful fluorescence labeling and activation.
Immerstrand
Charlotte
C
Division of Medical Microbiology, Department of Molecular and Clinical Medicine, Linköpings universitet, SE-581 85 Linköping, Sweden. chaim@imk.liu.se
Hedlund
Joel
J
Magnusson
Karl-Eric
KE
Sundqvist
Tommy
T
Peterson
Kajsa Holmgren
KH
D000818:Animals; D001692:Biological Transport; D007091:Image Processing, Computer-Assisted; D008027:Light; D008547:Melanophores / Q000166:cytology* / Q000378:metabolism; D015388:Organelles / Q000378:metabolism*; D010860:Pigments, Biological / Q000378:metabolism; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*; D014982:Xenopus laevis
D010860:Pigments, Biological