QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

Help viewing high resolution images Return to article

Fig. 1. Dynamic development of podosome organization during osteoclast polarization. RAW cells, either stably expressing GFP-actin or transiently transfected with YFP-paxillin, were induced to differentiate into osteoclasts and were recorded at 15-second intervals by time-lapse microscopy. (A) Temporal ratio images of GFP-actin. Four distinct, consecutive stages of podosome organization are shown: Individual podosomes (ind pod/cluster) (see arrow); clusters; rings; and sealing-zone-like (SZL) structures. Temporal ratio images indicate new podosomes (~1-minute old) in blue, podosomes that disappeared within the same minute of recording, in red, and more stable podosomes in yellow (see color legend in Figure). Actin reorganization in individual podosomes and clusters is slower than in ring and SZL structures. Note that clustered podosomes are less dynamic than ring podosomes within the same cell (ring, marked with arrowhead). (B) The quantitative data represent the average podosome life span (ALS) ± s.d., based on GFP-actin movies of five cells for every structure, obtained in three independent experiments. A total of 240 podosomes were examined for clusters and SZL structures; 220 podosomes were examined for rings. Statistical analysis based on the Student's t-test showed significant differences between cluster and ring structures (P<5 x10^-41), and cluster and SZL structures (P<5 x10^-41). (C) Temporal ratio image of YFP-paxillin. Paxillin ring domains in individual podosomes and clusters appeared less dynamic than in rings. Note the transition from an individual podosome to a cluster (ind pod/cluster 1' and 4', arrow). The SZL structure is a stable, continuous structure. The apparent sliding of the SZL structure was evident in the 10' temporal ratio image. Bars, 10 µm.

Return to article