Centrosomes are the main microtubule organizing centers in a cell, and their position is crucial in processes such as mitosis, cell migration, and cell differentiation. During cell migration, centrosomes are positioned in front of the nucleus, facing the leading edge of the cell, and help maintain a polarized cytoskeleton. A recent paper describes how polarity proteins and the microtubule motor dynein function at the leading edge of crawling cells in order to regulate centrosome position. The images above highlight a microscopy technique called TIRF (total internal reflection fluorescence) microscopy, in which only shallow regions of the cell are illuminated and imaged, just above the glass coverslip where they are crawling in this case (crawling towards dotted line). In these images, microtubules (middle, red) are found at the very leading edge of the crawling cell (whole cell is top, green).
BONUS!! Cool movies of crawling cells here.
Manneville, J., Jehanno, M., & Etienne-Manneville, S. (2010). Dlg1 binds GKAP to control dynein association with microtubules, centrosome positioning, and cell polarity Originally published in The Journal of Cell Biology, 191 (3), 585-598 DOI: 10.1083/jcb.201002151