I was excited last week to find myself writing about an entirely new way that cells communicate in the developing embryo. The work happened like this: Geneticist and developmental biologist Maria Barna, PhD, and her colleagues wanted to use advanced, high-resolution microscopy to investigate how cells in developing chick and mouse embryos send signals to one another across relatively large distances. When they looked at individual cells, they stumbled upon a previously invisible structure that resembles long, very thin fingers that burrow through densely packed cells to reach neighbors several cell-lengths away. (Conventional fixation and imaging techniques destroy these 'specialized filopodia'.) They then watched as the cells used these structures to deliver and receive payloads of signaling molecules to one another. Their research is published in the current issue of Nature.
From our release:
The seeming specificity of the interaction contrasts starkly with the commonly held notion that signaling molecules are released from one cell and float, or diffuse, through the intercellular space to their targets. While this finding does not preclude the use of diffusion as a signaling method, it identifies another new, surprising avenue of long-distance cellular communication.
I can't stop marveling at how scientists are still discovering entirely new unique parts of a cell. Apparently others feel the same: The work was featured this week on the Los Angeles Times' health and science blog (including a cool video of the filopodia grasping one another) and by the California Institute for Regenerative Medicine. Because the work was conducted while Barna was a faculty member at the University of California-San Francisco, they also wrote about the work.
Photoof filopodia by Esther Llagostera
