Latest Mitosis Stories
Stowers researchers gain new insight into the chromosome separation process Each time a cell divides -- and it takes millions of cell divisions to create a fully grown human body from a single fertilized cell -- its chromosomes have to be accurately divvied up between both daughter cells. Researchers at the Stowers Institute for Medical Research used, ironically enough, the single-celled organism Saccharomyces cerevisiae -- commonly known as baker's yeast -- to gain new insight into the...
The histone protein CenH3 is both necessary and sufficient to trigger the formation of centromeres and pass them on from 1 generation to the next Centromeres are specialised regions of the genome, which can be identified under the microscope as the primary constriction in X-shaped chromosomes. The cell skeleton, which distributes the chromosomes to the two daughter cells during cell division, attaches to the centromeres. In most organisms the position of the centromere is not determined by...
An international team of scientists, including biologists from the University of North Carolina at Chapel Hill, may have pinpointed for the first time the mechanism responsible for cell polyploidy, a state in which cells contain more than 2 paired sets of chromosomes. When it comes to human chromosomes and the genes they carry, our tissue cells prefer matched pairs. Bundled within the nucleus of our cells are 46 chromosomes, one set of 23 inherited from each of our parents. Thus, we are...
Understanding the endocycle has implications for agriculture and medicine An international team of researchers led by investigators in the U.S. and Germany has shed light on the inner workings of the endocycle, a common cell cycle that fuels growth in plants, animals and some human tissues and is responsible for generating up to half of the Earth's biomass. This discovery, led by a geneticist at Fred Hutchinson Cancer Research Center and reported Oct. 30 in Nature, leads to a new...
In order for cells of different types to maintain their identities even after repeated rounds of cell division, each cell must "remember" which genes were active before division and pass along that memory to its daughter cells. Cells deal with this challenge by deploying a "bookmarking" process. In the same way a sticky note marks the last-read page in a book, certain molecules tag the active genes in a cell so that, after it divides, the same genes are reactivated right away in the new...
Researchers at the California Institute of Technology (Caltech) have obtained the first high-resolution, three-dimensional images of a cell with a nucleus undergoing cell division. The observations, made using a powerful imaging technique in combination with a new method for slicing cell samples, indicate that one of the characteristic steps of mitosis is significantly different in some cells. During mitosis, two sets of chromosomes get paired up at the center of the cell's nucleus. Then...
Researchers at IRB Barcelona discover a crucial mechanism controlling the segregation of genetic material from parent to daughter cells. A finely tuned process of degradation tightly regulates CenH3 protein levels to ensure the correct function of the cell division machinery in Drosophila. From bacteria to humans, all forms of life are based on the capacity of one cell to divide into two or more identical daughter cells. In doing so, cells have to produce a copy of their genetic material...
When an egg cell is being formed, the cellular machinery which separates chromosomes is extremely imprecise at fishing them out of the cell's interior, scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have discovered. The unexpected degree of trial-and-error involved in this process could explain why errors in the number of chromosomes in the egg cell are the leading cause of miscarriages and severe congenital diseases such as trisomies like Down's...
Discovery may have implications for many diseasesCells are the building blocks of the human body. They are a focus of scientific study, because when things go wrong at the cellular and molecular level the consequences for human health are often significant.A new finding based on multiple collaborations between UNC and Duke scientists over several years points to new avenues for investigation of cell metabolism that may provide insights into diseases ranging from neurodegenerative disorders...
"˜Cord-stopper' protein complex makes chromosomes easier to moveAs any rock-climber knows, trailing a long length of rope behind you is not easy. A dangling length of rope is unwieldy and hard to manoeuvre, and can get tangled up or stuck on an outcropping. Cells face the same problem when dragging chromosomes apart during cell division. The chromosomes are pulled by their middle "“ the centromere "“ their arms trailing along behind. Just like climbers carry their rope coiled up, cells...
