Synopsis: Are eccentric cells better scouts?

A theoretical approach explores the role of shape in the ability of cells to sense environmental changes.
Synopsis figure
Credit: Carin Cain

To locate food sources or escape harmful elements, cells determine concentration gradients in the chemicals within their environment. Given their small size, cells must be able to detect a difference of a few tens of molecules across their length, making the detection process intrinsically stochastic. Within this constraint, Bo Hu and colleagues at the University of California, San Diego, develop a theoretical model to understand the role a cell’s shape plays in determining concentration gradients. Their work is presented in Physical Review E.

Hu et al. formulate the detection problem in terms of receptors on the surface of the cell that can be either bound (“on”) or unbound (“off”) to an external molecule. The probability of a receptor being on depends on the local concentration of chemicals. The team uses a statisticial approach to calculate the uncertainty in determining the two parameters that define a concentration gradient—magnitude and direction—by maximizing the likelihood of any one particular pattern of on and off receptors.

The authors find that cells can change the relative precision with which these two parameters can be estimated by adopting elliptical shapes, but they cannot improve the detection of a gradient’s direction and magnitude simultaneously. Similarly, cells can improve gradient detection in certain directions at the expense of others by, for example, increasing the density of chemical receptors at certain points on the cell surface. – Ralf Bundschuh


Announcements

More Announcements »

Subject Areas

Biological Physics

Previous Synopsis

Superconductivity

Hidden simplicity

Read More »

Next Synopsis

Quantum Information

A few good photons

Read More »

Related Articles

Synopsis: Maintaining the Sequence
Biological Physics

Synopsis: Maintaining the Sequence

Theoretical calculations indicate that an electrospray-based technique could correctly read out the amino acid sequence of protein molecules. Read More »

Synopsis: Neutron Stars in a Petri Dish
Nuclear Physics

Synopsis: Neutron Stars in a Petri Dish

Simulations of the dense matter in a neutron star’s crust predict the formation of structures that resemble those found in biological membranes. Read More »

Focus: Evolution Thins Out Distracting DNA
Biological Physics

Focus: Evolution Thins Out Distracting DNA

Proteins sometimes bind to the wrong stretch of DNA, but these "imposter" DNA sequences are statistically rare in many genomes, suggesting that evolution works against them. Read More »

More Articles