Lecture notes for Monday, February 18



Accumulation of cells in a specific place can be either by selective adhesiveness ("haptotaxis") or by chemotaxis.

Scientists tend to think of chemotaxis as ONE mechanism, But bacterial chemotaxis is by an increase in random turning when the attractant concentration decreases.

Leucocyte & Dictyostelium chemotaxis is by turning of locomotion toward the side where there is a higher concentration of attractant.



Two mechanisms of chemotaxis


Two videos of computer simulations of mechanisms of chemotaxis, with narration.

    first video: demonstration of behavioral rules that can produce the effects of chemotaxis

    second video: user's choice of different rules


Chemotaxis of a chick dorsal root axon toward a pipette containing nerve growth factor;
based on a classic paper by Gundersen and Barrett, 1979






back to syllabus