Navigation Links
Researchers shed light on shrinking of chromosomes

A human cell contains an enormous 1.8 metres of DNA partitioned into 46 chromosomes. These have to be copied and distributed equally into two daughter cells at every division. Condensation, the shortening of chromosomes, allows the cell to handle such huge amounts of genetic material during cell division and helps preventing fatal defects in chromosome separation. Now researchers from the European Molecular Biology Laboratory (EMBL) for the first time tracked chromosome condensation in mammalian cells over the entire course of cell division. In this week’s advanced online publication of Nature Cell Biology they report crucial new insights into timing, function and molecular basis of chromosome condensation.

What happens when chromosomes are not correctly separated and distributed during cell division we know very well; two daughter cells with either broken chromosomes or different numbers of chromosomes result and severe diseases including cancer can arise. But so far we know only little about condensation, a process crucial to the successful separation of chromosomes. Using powerful microscopes, researchers led by Jan Ellenberg at EMBL looked at living mammalian cells to find out how and when chromosomes shorten during cell division.

Condensation begins early, when the cell starts preparing for division, and the chromosomes become shorter and shorter until they are about to separate and migrate towards the poles of the cell.

“It is at this stage that textbooks say chromosomes are shortest. Then, after separating they would expand again,” says Ellenberg. “But we found something very different. Shortly after they finish separating, chromosomes actually condense even further. This makes sense, because in this way they are shortest when the physical division of one cell body into two takes place. Like this, no long chromosome arms extend over the plane of division, because that could expose the DNA to serious mechanical damage.”

Th e extreme condensation of chromosomes towards the end of cell division can also serve as a safety net if something goes wrong with chromosome separation in earlier phases of division. When the researchers added chemicals to the cell to block the late condensation, more separation defects appeared.

“Sometimes chromosomes get stuck and cannot be fully separated by the spindle that normally distributes them into the daughter cells,” says Felipe Mora-Bermúdez, who carried out the experiments in Ellenberg’s lab, “we think that the ‘super condensation’ at later stages helps to disentangle such chromosomes and acts as a back-up mechanism to rescue separation defects.”

The EMBL researchers found that an enzyme called Aurora kinase is crucially involved in this process. Blocking this enzyme abolishes late condensation of chromosomes. They now hope to uncover the detailed molecular mechanism underlying the late shortening of chromosomes. This could further advance our understanding of cell division and the risk factors that lead to defects in chromosome separation and their dramatic consequences.


'"/>

Source:European Molecular Biology Laboratory


Related biology news :

1. Researchers discover way to make cells in the eye sensitive to light
2. Researchers find how protein allows insects to detect and respond to pheromones
3. Researchers Uncover Key Step In Manufacture of Memory Protein
4. Researchers reveal the infectious impact of salmon farms on wild salmon
5. Researchers identify target for cancer drugs
6. Researchers discover molecule that causes secondary stroke
7. Researchers find missing genes of ancient organism
8. Researchers trace evolution to relatively simple genetic changes
9. Researchers add new tool to tumor-treatment arsenal
10. UF Researchers Map Bacterial Proteins That Cause Tooth Loss
11. VCU Researchers Identify Networks Of Genes Responding To Alcohol In The Brain

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/11/2017)... No two people are believed to ... York University Tandon School of Engineering and Michigan ... partial similarities between prints are common enough that ... and other electronic devices can be more vulnerable ... in the fact that fingerprint-based authentication systems feature ...
(Date:4/5/2017)... NEW YORK , April 5, 2017 ... security, is announcing that the server component of the ... is known for providing the end-to-end security architecture that ... customers. HYPR has already secured over 15 ... system makers including manufacturers of connected home product suites ...
(Date:3/30/2017)... ANGELES , March 30, 2017  On April ... Hack the Genome hackathon at Microsoft,s ... exciting two-day competition will focus on developing health and ... Hack the Genome is the ... been tremendous. The world,s largest companies in the genomics, ...
Breaking Biology News(10 mins):
(Date:10/10/2017)... 10, 2017 SomaGenics announced the receipt of ... develop RealSeq®-SC (Single Cell), expected to be the first ... (including microRNAs) from single cells using NGS methods. The ... to accelerate development of approaches to analyze the heterogeneity ... "New techniques for measuring levels of mRNAs in individual ...
(Date:10/9/2017)... 2017  BioTech Holdings announced today identification and ... ProCell stem cell therapy prevents limb loss in ... demonstrated that treatment with ProCell resulted in more ... compared to standard bone marrow stem cell administration.  ... reduction of therapeutic effect.  ...
(Date:10/9/2017)... ... October 09, 2017 , ... ... line of medical marijuana products targeting the needs of consumers who are incorporating ... Kindred takes place in Phoenix, Arizona. , As operators of two successful Valley ...
(Date:10/7/2017)... ... October 06, 2017 , ... ... launched its ProxiMeta™ Hi-C metagenome deconvolution product, featuring the first commercially available ... bioinformatics software to perform Hi-C metagenome deconvolution using their own facilities, supplementing ...
Breaking Biology Technology: