Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

BubR1: new clues for Down Syndrome?

17.08.2007
Scientists in Portugal and the US have discovered a key mechanism involved in the correct separation of chromosomes during the formation of eggs and sperm.

The research about to be published in the journal Current Biology shows that BubR1- a gene recently shown to affect cell division – maintains the cohesion of paired chromosomes (until their time to divide) during the production of reproductive cells. Because BubR1 mutations can result in cells with abnormal numbers of chromosomes, the research has potential implications for human disorders resulting from loss or gain of chromosomes such as Down Syndrome, a disease caused by an extra copy of chromosome 21.

Deletion of the BubR1 gene has been shown to disturb chromosome separation during meiosis - the process by which the reproductive cells, sperm and eggs, are formed - although how this happens is not clear. Following the discovery of a non-lethal BubR1 mutation in fruit flies Nicolas Malmanche, Claudio E. Sunkel and colleagues– which have had a long time interest in cell division - decided to try and identify the molecular role of this gene in meiosis. Fruit flies are particularly advantageous in this case as males and females of the species use different molecular mechanisms for the distribution of chromosomes between cells during meiosis, allowing a more detailed analysis of the effects of the BubR1 mutation and consequently also of BubR1 normal role.

Cells normally have two sets of each chromosome (called homologue chromosomes) where one set has come from the father and the other set of the mother. Meiosis - the specialised cell division that produces the sperm and eggs - starts with the duplication of all the chromosomes in the cell – that at this stage stay linked and are called (sister) chromatids - followed by two sets of divisions. During the first division homologues chromosomes are separated with each of the two daughter cells receiving one, while in the second division it is the sister chromatids that are separated with each sex cell receiving one from each pair.

... more about:
»BubR1 »Distribution »Sunkel »Syndrome »meiosis »sperm

It was by analysing and comparing mutated BubR1 and normal flies throughout these processes that Malmanche, Sunkel and colleagues were able to discover that the BubR1 gene is essential to maintain sister chromatids’ linked throughout meiosis, assuring in this way a correct distribution of the genetic material in the produced sex cells. The researchers also saw that in BubR1 mutated females, a complex structure called Synaptonemal Complex (SC), which binds homologue chromosomes during the first division of the meiosis and allows recombination (exchange of genetic material between homologous chromosomes, which is essential for generation of diversity) was also disrupted. Accordingly, detailed analysis of this process of recombination in BubR1 mutant cells revealed significant alterations in its frequency and distribution.

Malmanche, Sunkel and colleagues’ discoveries reveal BubR1 gene as crucial for a proper distribution of the genetic material during eggs and sperm formation in fruit flies. But because BubR1 is conserved throughout species and also exist in humans the research have potential implications for the study of human diseases caused by abnormal chromosomal distribution such as Down’s syndrome, which incidence increases with the mother’s age and can affect as much as 4% of the births in women over 45 years old.

Most significantly Down Syndrome individuals are known to have abnormal patterns of recombination and loss of cohesion between sister chromatids exactly like the defects observed in fruit flies with a mutant BubR1gene. As Claudio Sunkel says, “our observations suggest for the first time that inappropriate or reduced function of a gene like BubR1 might be at the heart of age-related chromosome imbalance observed in humans”.

Piece researched and written by Catarina.Amorim at linacre.ox.ac.uk

Catarina Amorin | alfa
Further information:
http://www.current-biology.com/

Further reports about: BubR1 Distribution Sunkel Syndrome meiosis sperm

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

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...

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

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>