Tag Archives: cell division

Scientists discover an unexpected influence on dividing stem cells’ fate

Scientists reveal an unexpected influence on dividing stem cells' fateWhen it divides, a stem cell has a choice: produce more stem cells or turn into the specific types of cells that compose skin, muscle, brain, or other tissue. New experiments in skin show this decision can be altered if tiny organs within cells aren’t positioned and divvied up properly. More »

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Researchers probe the physical forces involved in creating the mitotic spindle

Researchers probe the physical forces involved in creating the mitotic spindleScientists have gained new insight into the formation of the spindle, which is the molecular machine that divides up genetic material prior to cell division. Their work focuses on the motor protein, kinesin-5, which helps to organize the spindle’s filaments. More »

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Agata Smogorzewska, who studies DNA repair, promoted to associate professor

Agata Smogorzewska, who studies DNA repair, promoted to associate professorSince arriving in 2009, Smogorzewska has investigated a type of DNA repair that occurs during cell division when cells remove misplaced links between DNA strands. To identify the genes and understand the molecular mechanisms involved, she investigates this repair through the lens of rare genetic disorders. More »

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Mutations linked to genetic disorders shed light on a crucial DNA repair pathway

Mutations linked to genetic disorders shed light on a crucial DNA repair pathwayResearchers have identified two new genes in which mutations can interfere with a cell’s ability to remove misplaced links between DNA strands, and, as a result, cause a rare genetic disorder known as Fanconi anemia. These discoveries offer new insight on a repair process critical to maintaining certain tissues and preventing cancer. More »

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New technique reveals a role for histones in cell division

New technique reveals a role for histones in cell divisionResearchers have found that key aspects of cell division, such as the formation of the support structure for the envelope that surrounds the nucleus, depend on the presence of DNA-organizing proteins known as histones. More »

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Friction harnessed by proteins helps organize cell division

Researchers have found that the fastener proteins that organize cell division can harness the movement around them to do their work. Movement of filaments within the structure responsible for cell division can cause some of these proteins to shuffle along the path of least resistance and into position. More »

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Checkered history of mother and daughter cells explains cell cycle differences

In preparing to divide, mother and daughter cells use different gears and levers to regulate their genes. A collaboration between two geneticists and their labs now reveals that this difference in gene expression ultimately affects the protein CLN3, the levels of which certify whether a cell is ready to commit to another grueling round of cell division. The work sets a new compass point for studying how cell division may go awry in different types of cancer. More »

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A positive-feedback system ensures that cells divide

Every time a cell makes the decision to divide, it faces a formidable task: synchronizing the activity of hundreds of genes and proteins so that two daughter cells can be born. Now, Rockefeller University researchers show that a positive-feedback loop helps keep these events in sync — a finding that has eluded scientists for decades. More »

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Dividing cells find their middle by following a protein ‘contour map’

Self-organization keeps schools of fish, flocks of birds and colonies of termites in sync. It’s also, according to new research, the way cells regulate the final stage of cell division. Scientists at Rockefeller University have shown that a protein-chemistry-based contour map, which helps individual proteins locate the center of their cell without direction from a “master organizer,” is key to ensuring accurate division during mitosis. More »

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Device allows scientists to control gene activity across generations of cells

A group of biophysicists at Rockefeller University has developed a new tool that can control and measure, more precisely than before, the activity of genes and proteins within single budding yeast cells as they divide and multiply. The device may yield new insight into the functioning of regulatory networks. More »

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Mammalian protein plays unexpected role in cell division, and perhaps cancer

In yeast, the protein Tel2 regulates the length of telomeres, DNA sequences that protect the ends of linear chromosomes. But in humans and mice, Tel2 does nothing of the sort. Instead, researchers at Rockefeller University are the first to show that mammalian Tel2 prevents the degradation of a family of six proteins that primarily regulate cell division and proliferation, an unexpected role that may be linked to cancer. More »

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Sizing cells up: Researchers pinpoint when a cell is ready to reproduce

Like people, cells must reach a certain size before they can reproduce. A collaboration between Rockefeller University biologists, physicists and mathematicians shows how and when cells reach this size requirement, findings that provide researchers with a new quantitative framework to get to the core mechanisms involved in how a cell monitors its size. More »

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Chromosomes are responsible for a critical enzyme’s activation during cell division

The microtubule structures that chromosomes use to migrate to opposite ends of a cell must have impeccable timing: They need to materialize when chromosomes are present, then dissipate when they’re no longer needed. Now, new research suggests that the enzyme Aurora B is the reason that the microtubules show up on time. More »

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‘Hitchhiking’ chromosomes yield new theory of cell division

From the moment the cell was discovered, scientists have been dissecting the methodical, multi-step process by which they duplicate themselves. This week, Rockefeller researchers studying one component of this process — how a cell’s chromosomes move in preparation for division — announce a discovery that overturns current cell-division theory. More »

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Clearing jams in the copy machinery

Bacteria and humans use a number of tools to direct perhaps the most important function in cells — the accurate copying of DNA during cell division. Now, Rockefeller scientists show that one of these proteins, the beta sliding clamp, serves as a toolbelt, from which the correct proteins are retrieved to enable DNA replication in the face of DNA damage. More »

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Rockefeller researchers show evidence of asymmetric cell division in mammalian skin

By orienting cell division perpendicular to the bottom layer, cells automatically create two different daughters, one that stays in the basal layer and one that differentiates. The findings may lead to a better understanding of stem cell maintenance. More »

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Rockefeller researchers identify new role for key protein that regulates separation of DNA in dividing cells

Rockefeller University scientists have revealed a new function of a key component of the mechanism that cells use to accurately separate chromosomes when they divide. Disruptions in this process can cause diseases such as cancer. More »

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Preparing for a safe split

As it prepares to divide, a human cell makes exact copies of all of its 46 chromosomes, so that the two daughter cells each can have a complete set of genetic material. The two sets must separate equally, otherwise the new cells end up with the wrong number of chromosomes. Such problems are common in cancer cells, and have been linked to several types of birth defects. More »

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What inspires yeast cells to divide?

Often in science a novel set of experiments comes along that forces researchers to abandon old models in exchange for new ones that better fit their observations. This is the case in a new Nature report by Rockefeller University researchers, which finds that past models of cellular division in the simple yeast organism were focused on the wrong protein. More »

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How Aging Cells Retire

As we grow older, our hair turns gray, our bones grow thin and, among other changes, our telomeres shrink. But, more than markers of the passage of time, telomeres, the tips of chromosomes, may harbor answers to the fundamental mechanisms of aging and cancer. More »

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