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 A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>