Fluorescence analysis of pericentrin^long and pericentrin^short cell lines. (A) Diagram of pericentrin^long and pericentrin^short BAC constructs. Pericentrin^short lacks a 29.5-kb region of genomic DNA present in pericentrin^long, including the PACT domain (red). The green and yellow box represents the GFP cassette. (B) Pericentrin^long and pericentrin^short show distinct cell cycle localizations. Still images from videos of GFP fluorescence are shown. (top) Pericentrin^long localizes to centrosomes throughout the cell cycle. (bottom) Pericentrin^short only shows centrosomal localization in mitosis. (C) Immunofluorescence showing pericentrin^short localization to centrosomes. Mitotic but not interphase centrosomes are stained by anti-GFP (pericentrin^short), whereas anti-pericentrin antibody labels all centrosomes. Arrows point to the location of interphase centrosomes. (bottom) Enlarged images of the above boxed regions are shown, containing two prophase/prometaphase centrosomes and one interphase centrosome. Cells are stained for α-tubulin, GFP (pericentrin^short), pericentrin, and DNA. Bars, 10 µm.