Related Experiment Video
Updated: Jul 9, 2026
08:37
A Video Demonstration of Preserved Piloting by Scent Tracking but Impaired Dead Reckoning After Fimbria-Fornix Lesions in the Rat
Published on: April 24, 2009
Is there a pilot in a pseudopod?
1Ruder Bosković Institute, Department of Molecular Biology, Bijenicka 54, HR-10000 Zagreb, Croatia. iweber@irb.hr
European Journal of Cell Biology
|June 20, 2006
Summary
Pilot pseudopodia, initially thought to sense chemoattractants, are re-evaluated. New findings suggest they enhance cell elongation, improving navigation during chemotaxis.
Area of Science:
- Cell Biology
- Biophysics
- Biochemistry
Background:
- The concept of pilot pseudopodia was proposed in 1975 to explain cell navigation during chemotaxis.
- Pilot pseudopodia were hypothesized to act as sensory organelles detecting chemoattractant gradients.
Purpose of the Study:
- To re-evaluate the role of pilot pseudopodia in cell motility.
- To integrate recent findings on pseudopod dynamics and chemotaxis regulation.
Main Methods:
- Literature review and reinterpretation of existing data.
- Analysis of recent findings on cell morphology, pseudopod dynamics, and molecular regulators.
Main Results:
- Chemoattractant stimulation modulates pseudopod protrusion speed, leading to cell elongation.
- Cell elongation enhances sensitivity to shallow chemoattractant gradients.
- Elongation reinforces cell polarization and suppresses lateral pseudopodia.
Conclusions:
- Pilot pseudopodia contribute to chemotaxis by modulating cell shape and polarization.
- Enhanced cell elongation improves navigation efficiency in shallow gradients.
- The revised model offers a new perspective on cell-gradient sensing mechanisms.
Related Concept Videos
02:57piRNA - Piwi-interacting RNAs
PIWI-interacting RNAs, or piRNAs, are the most abundant short non-coding RNAs. More than 20,000 genes have been found in humans that code for piRNAs while only 2000 genes have been found for miRNAs. piRNAs can act at the transcriptional and post-transcriptional levels and have a vital role in silencing transposable elements present in germ cells. They are also involved in epigenetic silencing and activation. Previously, they were thought to function only in germ cells but new evidence suggests...
01:24Absolute Motion Analysis- General Plane Motion
Visualize a drone, with its propellers spinning rapidly, hovering mid-air. The fascinating movements and operations of this drone can be comprehended by applying the principle of general plane motion.
As the drone's propellers rotate, an upward force is generated that counteracts the force of gravity, enabling the drone to lift off from the ground. This initial movement of the drone is along a straight path, representing a form of translational motion. In this phase, every point on the drone...
As the drone's propellers rotate, an upward force is generated that counteracts the force of gravity, enabling the drone to lift off from the ground. This initial movement of the drone is along a straight path, representing a form of translational motion. In this phase, every point on the drone...
01:21Pilot and Numeric Relaying
Pilot relaying is a type of differential protection used in power systems. It compares electrical quantities at the terminals of equipment via a communication channel instead of direct relay interconnection. This method is essential for transmission lines where the terminals are far apart, typically up to 80 km for lines with 69 to 115 kV ratings. Four types of communication channels are used for pilot relaying:
01:28Fimbriae, Pili, and Axial Filaments
Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of pilin protein, these hairlike appendages are crucial for bacterial survival and pathogenicity in various environments.Fimbriae: Adhesion and PathogenicityFimbriae are fine, filamentous structures measuring 2–10 nanometers in diameter and are densely distributed on the bacterial cell surface. They facilitate bacterial adhesion to abiotic...
01:23Surface Appendages of Archaea
Archaeal surface appendages are highly specialized structures essential for environmental adaptation, encompassing roles in adhesion, biofilm formation, and motility. Among these appendages, pili and archaella stand out for their distinct morphologies and functionalities, enabling archaea to thrive in diverse and often extreme environments.Pili: Adhesion and Biofilm FormationPili are filamentous structures assembled from pilin protein subunits, primarily contributing to adhesion and biofilm...
01:31Planes in Space
A plane in three-dimensional space is fundamentally characterized by a point that lies on the plane and a normal vector that is perpendicular to its surface. This normal vector uniquely determines the orientation of the plane, making it an essential geometric descriptor. In architectural applications, such as the installation of a sloped glass panel on a building façade, this mathematical model provides a precise representation of the panel’s position and orientation in space.Let r₀ be the...