Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fertility genes discovered at Rugters

20.12.2005


Rutgers geneticists have reported groundbreaking research on the genetics of fertility. They have discovered two genes, aptly named egg-1 and egg-2, required for fertilization to take place. The proteins encoded by these genes are similar to low density lipoprotein (LDL) receptors, known from cholesterol and fat metabolism but never before specifically implicated in fertilization.



One in six couples is experiencing fertility problems worldwide, and people are asking why. This is a question of great medical, social and economic importance – one that cannot be answered until the process of fertilization is more fully understood.

A team led by Andrew Singson, an assistant professor and Pavan Kadandale, a graduate student in the Singson lab at the Waksman Institute of Microbiology at Rutgers, The State University of New Jersey, has taken a new and productive approach in this quest. The researchers found that in the absence of these two genes, the vital process of fertilization came to a halt. "What we learn in studying fertilization is not only important for this event, but also for the functioning of other cells in our bodies and for understanding many of those processes," Singson said.


Fertilization can be a paradigm for gaining insight into how cells interact over the life and development of multicellular organisms because it is one of the most basic of cell-cell interactions. The underlying cell biology is going to be universal with applications even in infectious diseases, such as AIDS, where the virus passes its genetic material to the cells it infects just as fertilization transmits sperm DNA to the egg, Singson explained.

Fertilization has primarily been studied in mammals or select marine invertebrates; but Singson and his group have instead turned to the lowly roundworm Caenorhabditis elegans (C. elegans), the first multicellular organism to have had its genome completely sequenced.

In addition to having its genome sequence, C. elegans offers particular advantages as a model system – one from which results can be extrapolated to other organisms including humans. The millimeter-long worm is transparent, allowing a clear view of its internal workings, and its short life cycle permits researchers to chronicle developmental and hereditary factors over generations. These properties have enabled researchers to use C. elegans for fundamental discoveries in other fields ranging from cell death and life span regulation to nervous system structure and function.

But the worm’s most important attribute as a model for this work may be its curious reproductive biology. Worms exist as males or hermaphrodites. When hermaphrodites are young they produce sperm and switch to produce eggs as adults. The Rutgers researchers were thus able to alter eggs in the hermaphrodites and use sperm from young males to test fertilization.

Genetic tools such as RNA interference (a way of removing gene function) and gene "knockout" mutants were used to see what would happen if worms lacked the function of egg-1 or egg-2 genes. The results were that the worms became sterile because fertilization had failed to occur. Normal sperm could no longer enter the eggs produced by egg-1 and egg-2 mutant hermaphrodites.

The traditional biochemical approach to studying fertilization has been to collect sperm and eggs and try to separate all the molecules or components of the cells, then discern how they might function in fertility. Singson admits that this has been productive, but he says that the definitive test for a role in fertilization or any biological process is to completely remove that molecule, or the gene that codes for it, and watch what happens.

"If you get infertility, then you know that the molecule is required for fertility, and this is our ’smoking gun.’ Basically, we are asking the animal to tell us what it requires for its fertility, and then we try to understand how it works on a molecular level," he said. "Our use of this genetic approach, which hasn’t been generally done in the past, is, indeed, groundbreaking."

Singson’s group picked the two "egg" genes as an educated guess based on research Singson had previously conducted with a group of sperm genes. Mutations in sperm genes prevented the sperm from fertilizing normal eggs. The hope was that the sperm genes, together with the newly discovered egg genes, would be the "lock and key" that mediate normal fertilization.

For a sperm to enter an egg, the sperm has to recognize the egg and ignore other sperm or cells in the environment, Singson explained. Then there are interactions needed to get the surface membranes of both sperm and egg to fuse, a critical initial step in fertilization.

The results described in the Dec. 20 issue of Current Biology by Kadandale et al. confirm that along with the previously identified sperm genes, the egg-1 and egg-2 encoded molecules are a key component of the cellular machinery required for successful fertilization in worms.

"Ultimately," Singson said, "it will be exciting to determine if defects in similar molecules can lead to human infertility."

Joseph Blumberg | EurekAlert!
Further information:
http://www.rutgers.edu

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton 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: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>