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 Solving the efficiency of Gram-negative bacteria
22.03.2019 | Harvard University

nachricht Bacteria bide their time when antibiotics attack
22.03.2019 | Rice 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: The taming of the light screw

DESY and MPSD scientists create high-order harmonics from solids with controlled polarization states, taking advantage of both crystal symmetry and attosecond electronic dynamics. The newly demonstrated technique might find intriguing applications in petahertz electronics and for spectroscopic studies of novel quantum materials.

The nonlinear process of high-order harmonic generation (HHG) in gases is one of the cornerstones of attosecond science (an attosecond is a billionth of a...

Im Focus: Magnetic micro-boats

Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.

The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...

Im Focus: Self-healing coating made of corn starch makes small scratches disappear through heat

Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.

Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...

Im Focus: Stellar cartography

The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.

A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...

Im Focus: Heading towards a tsunami of light

Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.

"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Solving the efficiency of Gram-negative bacteria

22.03.2019 | Life Sciences

Bacteria bide their time when antibiotics attack

22.03.2019 | Life Sciences

Open source software helps researchers extract key insights from huge sensor datasets

22.03.2019 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>