Featured Research

from universities, journals, and other organizations

Sperm can do 'calculus' to calculate calcium dynamics and react accordingly

Date:
March 7, 2012
Source:
Max-Planck-Gesellschaft
Summary:
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. Scientists 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 maneuvering even in the presence of high calcium concentrations.

New research has found that the speed at which the calcium concentration in the cell changes controls the swimming behavior of sperm. They can calculate the calcium dynamics and react accordingly.
Credit: © Paco Ayala / Fotolia

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 Gφttingen, 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 maneuvering 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 1980s 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.


Story Source:

The above story is based on materials provided by Max-Planck-Gesellschaft. Note: Materials may be edited for content and length.


Journal Reference:

  1. L. Alvarez, L. Dai, B. M. Friedrich, N. D. Kashikar, I. Gregor, R. Pascal, U. B. Kaupp. The rate of change in Ca2 concentration controls sperm chemotaxis. The Journal of Cell Biology, 2012; 196 (5): 653 DOI: 10.1083/jcb.201106096

Cite This Page:

Max-Planck-Gesellschaft. "Sperm can do 'calculus' to calculate calcium dynamics and react accordingly." ScienceDaily. ScienceDaily, 7 March 2012. <www.sciencedaily.com/releases/2012/03/120307094421.htm>.
Max-Planck-Gesellschaft. (2012, March 7). Sperm can do 'calculus' to calculate calcium dynamics and react accordingly. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2012/03/120307094421.htm
Max-Planck-Gesellschaft. "Sperm can do 'calculus' to calculate calcium dynamics and react accordingly." ScienceDaily. www.sciencedaily.com/releases/2012/03/120307094421.htm (accessed July 29, 2014).

Share This




More Health & Medicine News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Generics Eat Into Pfizer's Sales

Generics Eat Into Pfizer's Sales

Reuters - Business Video Online (July 29, 2014) — Pfizer, the world's largest drug maker, cut full-year revenue forecasts because generics could cut into sales of its anti-arthritis drug, Celebrex. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
Nigeria Ups Ebola Stakes on 1st Death

Nigeria Ups Ebola Stakes on 1st Death

Reuters - Business Video Online (July 29, 2014) — Nigerian authorities have shut and quarantined a Lagos hospital where a Liberian man died of the Ebola virus, the first recorded case of the highly-infectious disease in Africa's most populous economy. David Pollard reports Video provided by Reuters
Powered by NewsLook.com
Running 5 Minutes A Day Might Add Years To Your Life

Running 5 Minutes A Day Might Add Years To Your Life

Newsy (July 29, 2014) — According to a new study, just five minutes of running or jogging a day could add years to your life. Video provided by Newsy
Powered by NewsLook.com
Ebola Outbreak Poses Little Threat To U.S.: CDC

Ebola Outbreak Poses Little Threat To U.S.: CDC

Newsy (July 29, 2014) — The Ebola outbreak in West Africa poses little threat to Americans, according to officials with the Centers for Disease Control and Prevention. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins