Tag Archives: chromosome

Wie bleibt genetisches Material während der Fortpflanzung intakt?

MolekularbiologInnen erforschen Prozesse beim Ausschneiden und Einfügen von DNA

Eltern vererben ihre genetische Information in Form von Chromosomen. Diese sind jedoch nicht einfache Kopien, sondern ein Mosaik aus den beiden Chromosomenkopien, die sie selbst erhalten haben. Die Herstellung dieser Mosaike erfolgt durch einen Prozess des Ausschneidens und Einfügens von Chromosomenstücken. Wie solche Schnitte – auch Brüche genannt – in unserem genetischen Material repariert werden, untersuchen Verena Jantsch und ihr Team an den Max F. Perutz Laboratories der Universität Wien und der Medizinischen Universität Wien. Ihre Ergebnisse geben wichtige Einblicke in die Prozesse, die sicherstellen, dass unser genetisches Material intakt bleibt und so genetische Krankheiten und Krebsentstehung verhindern.

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Elusive viral ‘machine’ architecture finally rendered

Biologists have worked with the lambda virus as a model system for more than 50 years but they’ve never had an overarching picture of the molecular machines that allow it to insert or remove DNA from the cells that it infects. Now they can, thanks to an advance that highlights the intriguingly intricate way the virus accomplishes its genetic manipulations.

PROVIDENCE, R.I. [Brown University] — For half a century biologists have studied the way that the lambda virus parks DNA in the chromosome of a host E. coli bacterium and later extracts it as a model reaction of genetic recombination. But for all that time, they could never produce an overall depiction of the protein-DNA machines that carry out the work. In a pair of back-to-back papers in the Proceedings of the National Academy of Sciences, scientists produce those long-sought renderings and describe how they figured out what they should look like. (more…)

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Racism May Accelerate Aging in African American Men

UMD-led study is first to link racism-related factors and cellular age

COLLEGE PARK, Md. – A new University of Maryland-led study reveals that racism may impact aging at the cellular level. Researchers found signs of accelerated aging in African American men who reported high levels of racial discrimination and who had internalized anti-Black attitudes. Findings from the study, which is the first to link racism-related factors and biological aging, are published in the American Journal of Preventive Medicine.

Racial disparities in health are well-documented, with African Americans having shorter life expectancy, and a greater likelihood of suffering from aging-related illnesses at younger ages compared to whites. Accelerated aging at the biological level may be one mechanism linking racism and disease risk. (more…)

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Intimate yeast: Mating and meiosis

Mating and meiosis – the specialized cell division that reduces the number of chromosomes in a cell – are related, but in most yeasts they are regulated separately. Not so in Candida lusitaniae, where the two programs work in unison, according to a new study in Nature. Comparison with other species suggests that this fusion may support C. lusitaniae’s “haploid lifestyle” of maintaining only one set of chromosomes in each cell.

PROVIDENCE, R.I. [Brown University] — From a biological point of view, the world’s most exotic sex lives may be the ones lived by fungi. As a kingdom, they are full of surprises, and a new one reported in the journal Nature seems sure to titillate the intellects of those who study the evolution of mating and ploidy, the complement of chromosomes in each cell. (more…)

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UMass Amherst Cell Biologists Show Molecular Forces Are Key to Proper Cell Division

AMHERST, Mass. – Studies led by cell biologist Thomas Maresca at the University of Massachusetts Amherst are revealing new details about a molecular surveillance system that helps detect and correct errors in cell division that can lead to cell death or human diseases. Findings are reported in the current issue of the Journal of Cell Biology.

The purpose of cell division is to evenly distribute the genome between two daughter cells. To achieve this, every chromosome must properly interact with a football-shaped structure called the spindle. However, interaction errors between the chromosomes and spindle during division are amazingly common, occurring in 86 to 90 percent of chromosomes, says Maresca, an expert in mitosis. (more…)

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UCLA Bioengineers Discover Single Cancer Cell Can Produce Up To Five Daughter Cells

Findings could aid researchers in understanding progression of disease

It’s well known in conventional biology that during the process of mammalian cell division, or mitosis, a mother cell divides equally into two daughter cells. But when it comes to cancer, say UCLA researchers, mother cells may be far more prolific.

Bioengineers at the UCLA Henry Samueli School of Engineering and Applied Science developed a platform to mechanically confine cells, simulating the in vivo three-dimensional environments in which they divide, and found that, upon confinement, cancer cells often split into three or more daughter cells.

“We hope that this platform will allow us to better understand how the 3-D mechanical environment may play a role in the progression of a benign tumor into a malignant tumor that kills,” said Dino Di Carlo, an associate professor of bioengineering at UCLA and principal investigator on the research. (more…)

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Chromosome Painting: Discovering beauty in DNA

Everyone has a genetic story.

For artist Geraldine Ondrizek, an art professor at Portland’s Reed College, her story begins with the tragic loss of her child to a condition caused by a genetic anomaly. It’s a story that starts with her efforts to piece together her family’s genetic history and that has brought her, in the years since, to a beautiful intersection of science and art that today defines the very essence of her work.

Since 2001, Ondrizek has worked with geneticists and biologists to gather images of human cellular tissue and genetic tests relating to disease, ethnic identity, and the depiction of genetically inherited conditions. (more…)

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Human Brain Evolution Tied to Partial Gene Copy That Blocks Original

A brain-development gene found exclusively in humans has an unusual evolutionary history and could contribute to what makes us distinctly human. Equally surprising, this is a partial gene created from an incomplete duplication of its “parent” gene in the prehistoric human genome.

Gene duplication is an important driving force in creating physical changes in living things during evolution, explained the researchers studying the SRGAP2 gene family. Drs. Megan Dennis and Xander Nuttle, in the Howard Hughes Medicine Institute research lab of Dr. Evan Eichler, University of Washington professor of genome sciences, co-authored the report on the findings. (more…)

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