Actin Out the Intestine
This purple and gold cell brings into focus the basic structure of an intestinal epithelial cell. The top of the cell (to the right) is covered with microvilli, which help absorb nutrients from the intestine, and the base of the cell (to the left) is responsible for transferring those nutrients to the bloodstream.
DownloadActin Out the Intestine
This purple and gold cell brings into focus the basic structure of an intestinal epithelial cell. The top of the cell (to the right) is covered with microvilli, which help absorb nutrients from the intestine, and the base of the cell (to the left) is responsible for transferring those nutrients to the bloodstream.
What am I looking at?
This is a video of an intestinal epithelial cell in culture, with actin filaments and actin cross-linking proteins outlining the dynamic nature of the microvilli (to the right) and the basal membrane (to the left). The actin filaments are gold, and the actin cross-linking proteins are purple.
Biology in the background
Actin proteins assemble to form a network of thin filaments that spread throughout all eukaryotic cells. These actin filaments give a cell its structure, allow the cell to move, and permit the formation of specialized structures like microvilli in intestinal epithelial cells. Actin, along with the actin cross-linking proteins that connect actin filaments, can push the cell membrane out into the environment around the cell, creating a long, thin protrusion covered in plasma membrane and supported by actin. This is important in intestinal epithelial cells because it provides more membrane surface area for nutrients to be absorbed through.
An actin filament can be up to 15 micrometers long, or roughly seven times smaller than the width of a human hair, and an actin cross-linking protein is about 35 nanometers long, or roughly 3,000 times smaller than the width of a human hair.
Technique
This video was created using confocal microscopy.
Jennifer B. Silverman, Tyska Laboratory, Vanderbilt University