Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2004 Mar 15;164(6):887–897. doi: 10.1083/jcb.200310055

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

Copyright © 2004, The Rockefeller University Press

This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).

PMC Copyright notice

Figure 2. — Characterization of the actin incorporation and flux. (A) Characterization of actin-GFP incorporation into the stereocilia actin paracrystal. The pixel intensity profile along an individual stereocilium (rectangular area) shows the sharp demarcation of the β actin–GFP incorporation (green), whereas the pixel intensity of the rhodamine/phalloidin counterstained actin filaments (red) shows a constant profile. The pixel intensity from the rhodamine/phalloidin shows the same profile when measured across the region of β actin–GFP incorporation or across the region without actin-GFP, excluding the possibility that incorporation was due to nucleation of additional actin filaments. Bar, 2 μm. (B) Transient β actin–GFP expression in an auditory hair cell. The serendipitous pulse of actin-GFP (green) expression was arrested midway along the stereocilia (left). The incorporation appears as a band that has progressed halfway along the stereocilia showing a sharp front facing the stereocilia base (similar to the stereocilia in C) and a diffuse attenuated trailing edge facing the tip. It also shows no change in the total actin fluorescence along the stereocilia, confirming that no anomalous actin filaments are added laterally to the actin paracrystal. Bar, 2 μm. (C) The extent of actin incorporation and treadmill rates is proportional to the length of the stereocilia in a bundle. Even at the earliest times of transfection, we could detect in the fluorescence confocal images that the actin-GFP incorporation starts at the same time in all stereocilia in a bundle but the rate of incorporation and subsequent actin treadmilling are proportional to the stereocilia length in both organ of Corti (left, 6 h after transfection) and vestibular (right, 18 h after transfection) hair bundles. Bar, 600 nm. (D and E) Relationship of the treadmill rates to the length of the stereocilia. The overall actin-GFP treadmill rates calculated by measuring lengths of incorporation 12–24 h after actin-GFP transfection and expressed as μm/24 h for the organ of Corti (D) and vestibular (E) stereocilia. The rate of actin treadmill is proportional to the length of the stereocilium irrespective of its rank (tall, middle, or short) within the staircase bundle.