Fig. 3. Chlamydial protein synthesis is required for aggregation at the MTOC. Cos-7 cells were infected for 5 hours with C. trachomatis in the absence (control) or presence of chloramphenicol or rifampicin and stained simultaneously with anti-L2 and anti-ß-tubulin antibodies. In the control cells the majority of nascent inclusions migrate to a single site (arrowheads) corresponding to the MTOC as can be seen in the merged image. However, the chlamydial inclusions do not migrate to the MTOC and remain scattered throughout the cytoplasm when the infection is carried out in presence of chloramphenicol or rifampicin. Bar, 10 µM.