Berlin 2015 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 17: Microswimmers (joint session DY, BP, CPP)
CPP 17.10: Vortrag
Dienstag, 17. März 2015, 12:00–12:15, BH-N 128
3D-tracking reveals how sperm find the egg — Jan F. Jikeli1, Luis Alvarez1, •Benjamin M. Friedrich2, and Laurence Wilson3 — 1CAESAR, Bonn, Germany — 2MPI PKS, Dresden, Germany — 3University of York, York, UK
Sperm cells are guided to the egg by chemical cues in a process termed chemotaxis.
We have previously put forward a theory of how sampling a concentration gradient along helical paths allows
sperm of marine species to steer up-gradient [1].
Now, high-speed tracking in three space dimensions allows to probe sperm navigation live.
We find that sperm display deterministic steering responses,
which sets their chemotaxis strategy apart from those employed by most bacteria (biased random walk) or immune cells (spatial comparison).
We dissect the control logic that links sensation and motor actuation in sperm chemotaxis.
We find that control delays are close to their theoretical optimum for up-gradient navigation.
The resultant navigation strategy is particularly well suited for fast swimmers operating at the limits of chemical detection.
The choice of optimal navigation strategy of a search agent is tightly linked to its susceptibilities for noise [2].
[1] B.M. Friedrich et al.: Chemotaxis of sperm cells, PNAS 33, 2007.
[2] L. Alvarez et al.: The computational sperm cell, Trends in Cell Biology 24, 2014.