The authors of two studies this week report findings that offer new insight into how breaks in chromosomes can lead to the so-called genomic instability that is a hallmark of cancer. When DNA is damaged, as it routinely is during the life of cells, the damage must be properly repaired in order to keep chromosomes intact. Failure of the DNA repair process disrupts the structural stability of chromosomes, which must be intact in order to be properly segregated to daughter cells when cells divide. Non-repaired or improperly fused chromosomes lead to chromosome breaks in mitosis and disruptions in gene activity that can lead to cancer. Unfortunately, the molecular events following DNA repair failure that lead to this genomic instability are only partly understood.
In the first study, researchers led by David Toczyski at UCSF and James Haber at Brandeis University fluorescently marked chromosomes at, or near, DNA breaks, and showed that the broken ends of yeast chromosomes remain held together even as cells attempt to separate them during cell division.
Normally, a single DNA break causes cells to arrest in metaphase of mitosis. Metaphase is a critical transition in the cell cycle because it is after this stage that chromosomes segregate to daughter cells. In their study, Toczyski and colleagues examined broken chromosomes both during the cells arrest in metaphase and after cells had overridden this arrest and attempted to segregate the broken chromosome. The researchers found that when both sister chromatids of a chromosome are cut -- a so-called double-strand break -- the two halves of a single broken sister chromatid often remain associated with each other through a mechanism involving DNA repair proteins; they also found evidence that the two sister chromatid fragments on one side of a chromosome break remain inappropriately associated during mitosis, leading to missegregation of the corresponding genetic material.
Heidi Hardman | EurekAlert!
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences