Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The end of the “Lily of the Valley phenomenon” in sperm research?

29.02.2012
Sperm cannot detect smells.

According to a 2003 study by German and American scientists, a component of the Lily of the Valley scent known as Bourgeonal alters the calcium balance of human sperm and attracts the sperm.

The “Lily of the Valley phenomenon” – also the title of a book about smelling – was born as a result of this discovery that sperm act as swimming olfactory cells which follow a “scent trail” laid by the egg. However, a detailed explanation for the Lily of the Valley phenomenon remained illusive as neither Bourgeonal nor other scents could be identified in the female sex organ.

Scientists from the caesar research centre in Bonn, an Institute of the Max Planck Society, have now discovered that sperm do not function like olfactory cells - a finding that casts doubt on the assumption that scents play a role in fertilisation.

Sperm have a long journey ahead in their quest for the egg cell or ovum, and just a few of the million sperm reach their destination. The ovum supports the sperm in their quest by transmitting “chemical signposts”, known as attractants. Researchers first discovered this ingenious system in sea urchins and found out that attractants control the swimming movement of the sperm by altering their calcium balance. The attraction of the sperm to the egg is referred to as “chemotaxis”. Unlike in sea urchins, which release sperm and eggs into the seawater, the conditions in the narrow human fallopian tube are very difficult to emulate in experiments.

According to another model, the female sex hormone progesterone – which is formed by cumulus cells near the ovum – attracts the sperm. CatSper (cation channels of sperm) ion channels are responsible for the effect of the progesterone. The CatSper channels, which are found only in sperm, play an indispensable role in reproduction: men who carry a gene defect for CatSper are infertile. In a 2011 study, which was seen as a sensational breakthrough, scientists from the caesar research centre succeeded in showing that progesterone opens the CatSper channels directly and calcium flows through the channels into the sperm cell.

In their current study, the Bonn researchers demonstrate, in cooperation with scientists from the Forschungszentrum Jülich, that the Lily of the Valley scent imitates the effect of progesterone on sperm: Bourgeonal opens the CatSper channels directly – that is without deviation via olfactory receptors and complex biochemical signalling pathways as found in olfactory cells. However, the scents only work at concentrations over 1000 times higher than progesterone. Therefore, scents only work if overdosed. The “Lily of the Valley phenomenon” is a laboratory artefact: sperm do not have an olfactory signalling pathway.

These findings provide important new insights for the sperm researchers. Why are the CatSper channels so unselective, and even react to menthol if the concentration is high enough? This “promiscuous” characteristic is probably crucial for reproduction. Using different “chemical signposts”, the sperm must repeatedly reassure themselves on their difficult journey to the ovum that they are still on the right track. With the help of the CatSper channels as versatile and highly perceptive sensors, sperm can “read” the chemical milieu in the fallopian tube and find the ovum in this way. The Bonn-based researchers are now concentrating on identifying other attractants in the fallopian tube in addition to progesterone. One thing is clear at this stage: it is very unlikely that these are scents.

The new insights are also significant in medical terms. If the scientists succeed in disrupting the effect of female factors on the CatSper channels, it could lead to the development of an innovative contraceptive: the pill for men. However, such a development is still a very long way off.

Dr. Timo Strünker | EurekAlert!
Further information:
http://www.mpg.de/5050272/attractants_sperm

More articles from Life Sciences:

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

nachricht Transforming plant cells from generalists to specialists
07.12.2016 | Duke University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

NTU scientists build new ultrasound device using 3-D printing technology

07.12.2016 | Health and Medicine

The balancing act: An enzyme that links endocytosis to membrane recycling

07.12.2016 | Life Sciences

How to turn white fat brown

07.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>