Navigation Links
Sperm can count

This release is available in German.

Sperm have only one aim: to find the egg. The egg supports the sperm in their quest by emitting attractants. Calcium ions determine the beating pattern of the sperm tail which enables the sperm to move. Together with colleagues from the Max Planck Institute for the Physics of Complex Systems in Dresden and the University of Gttingen, scientists from the caesar research centre in Bonn, an institute of the Max Planck Society, have discovered that sperm only react to changes in calcium concentration but not to the calcium concentration itself. Probably sperm make this calculation so that they remain capable of manoeuvring even in the presence of high calcium concentrations.

The swimming path on which sperm follow the mating call of the egg, varies according to species. Sperm in particular those of marine species swim along convoluted paths in a chemical concentration gradient. Their swimming style is controlled by the calcium ions in the sperm tail. It was previously believed that in high calcium concentrations, the sperm tails make asymmetrical, whip-like movements and their swimming path is very curved, while in low calcium concentrations, the tails beat symmetrically and the sperm swim on a straight line. The alternation of high and low calcium concentrations was thought to propel sperm along spiral-shaped swimming paths. However, this simple model was repudiated by experiments on freely-swimming sperm and presented researchers with something of a mystery.

The scientists have now succeeded in solving this mystery. Using ingenious stroboscopic laser illumination similar to that used in discotheques project leader Luis Alvarez was able to trace the movement of a sperm in detail, and simultaneously measure the changes in the calcium concentration. The result was astonishing: the sperm tail only reacted to the time derivative of the calcium concentration and the absolute concentration was of little relevance. To put it simply: sperm can count! Exactly how they do this is unclear. The caesar scientists suspect that sperm bind calcium ions with the help of two proteins and in thereby create a "chemical derivative", so to speak.

But why do sperm carry out this complicated kind of calculation that we first encounter at upper secondary school level? The concentration of the attractants and, therefore also, the calcium concentration in the sperm is very high near the egg. The mathematical trick probably enables the sperm to be able to react even in the presence of such high calcium concentrations.

Apart from calcium, many other messenger substances control cell functions. Is it possible, therefore, that cells also carry out complex chemical calculations involving other messenger substances? The Bonn scientists would like to investigate this important question next.


Contact: Luis Alvarez, Ph.D.

Related biology news :

1. Low sperm count may be associated with prenatal testosterone excess
2. Proteins in sperm unlock understanding of male infertility says new study
3. The more promiscuous the female, the speedier the sperm
4. CSHL scientists discover how companion cells to sperm protect them from genetic damage
5. The egg makes sure that sperm dont get too old
6. Spread your sperm the smart way
7. ESHREs workshop on freezing of human sperm, eggs and embryos in Athens
8. MMS and NOAA scientists study prey of Gulf of Mexico sperm whales
9. Molecular study could push back angiosperm origins
10. Females shut down male-male sperm competition in leafcutter ants
11. UT Southwestern researchers use novel sperm stem-cell technique to produce genetically modified rats
Post Your Comments:
(Date:11/17/2015)... , November 17, 2015 ... au 19 novembre  2015.  --> Paris ... --> DERMALOG, le leader de l,innovation biométrique, ... la fois passeports et empreintes sur la même surface ... les passeports et l,autre pour les empreintes digitales. Désormais, ...
(Date:11/16/2015)... Nov 16, 2015  Synaptics Inc. (NASDAQ: ... solutions, today announced expansion of its TDDI product ... touch controller and display driver integration (TDDI) solutions ... These new TDDI products add to the previously-announced ... TD4302 (WQHD resolution), and TD4322 (FHD resolution) solutions. ...
(Date:11/12/2015)... 11, 2015   Growing need for low-cost, ... has been paving the way for use of ... discrete analytes in clinical, agricultural, environmental, food and ... used in medical applications, however, their adoption is ... to continuous emphasis on improving product quality and ...
Breaking Biology News(10 mins):
(Date:12/1/2015)... Dec. 1, 2015 Frost & Sullivan ... This program addresses ways companies can innovate and ... --> ... --> ... as well as the disrupting factors altering the ...
(Date:12/1/2015)... ... December 01, 2015 , ... Park Systems , world ... scanning ion conductance microscopy module to Park NX10 that is the only product ... SICM benefits virtually all materials characterization that require measurements in liquid such as ...
(Date:12/1/2015)... December 1, 2015 Dr. Harry Lander , President of ... as Chief Science Officer and recruits five distinguished ... Lander , President of Regen, expands his role to include ... recruits five distinguished scientists to join advisory team ... expands his role to include serving as ...
(Date:11/30/2015)... (PRWEB) , ... November 30, 2015 , ... Global ... and development stages of a new closed system for isolating adipose-derived stem cells. The ... vascular fraction (SVF) of adipose tissue. SVF is a component of the lipoaspirate obtained ...
Breaking Biology Technology: