Latest Meiosis Stories
ESHRE study may answer the question in older womenOvarian stimulation undertaken by women of advanced maternal age (over 35 years) receiving fertility treatment may be disrupting the normal pattern of meiosis "“ a critical process of chromosome duplication followed by two specialised cell divisions in the production of oocytes and sperm "“ and leading to abnormalities of chromosome copy numbers (aneuploidy) that result in IVF failure, pregnancy loss or, more rarely, the birth of affected...
Egg cells failing to properly arrange chromosomesWashington State University researchers have confirmed a critical step in cell division that results in age-related miscarriages and birth defects, including Down syndrome.Writing in the upcoming issue of the journal "Current Biology," the researchers say they recreated the conditions in which an egg cell will continue to undergo cell division without properly arranging its chromosomes, creating offspring with aneuploidy, or an...
University of Pennsylvania biologists studying human reproduction have identified what is likely the major contributing factor to the maternal age-associated increase in aneuploidy, the term for an abnormal number of chromosomes during reproductive cell division.Using naturally aging mouse models, researchers showed that this basic fact of reproductive life is most likely caused by weakened chromosome cohesion. Older oocytes, or egg cells, have dramatically reduced amounts of a protein,...
A genetics research team based at The Children's Hospital of Philadelphia continues to discover recurrent translocations"”places in which two chromosomes exchange pieces of themselves. As many as 1 in 600 persons carry balanced chromosome translocations, which involve no loss or gain of DNA. Most such people appear healthy, but may have a child with abnormal chromosome composition and disabilities resulting from disrupted, extra or missing copies of genes.While rare, such diseases originate...
The research demonstrates that p53 is activated to control the creation of ova and spermatozoaProtein p53 is known as the guardian of the genome since it is basic for the genome's integrity by preventing the accumulation of mutations originating either by the cell's own mechanisms or by the action of external agents. The protein becomes activated in response to specific signals such as breaks in DNA. This activation implies a slowing of the cell's cycle which allows it to repair itself from...
Protein p53 is also activated to control the creation of ova and spermatozoidsProtein 53 is very important in protecting against cancer given that it prevents cancer-causing mutations from accumulating and its inactivation is closely linked to the proliferation of tumour cells. UAB lecturer Ignasi Roig participated in the study. Formed by an international research team, the study served to discover that this protein played an unexpected physiological role: it also becomes activated during the...
Meiosis "“ the pairing and recombination of chromosomes, followed by segregation of half to each egg or sperm cell "“ is a major crossroads in all organisms reproducing sexually. Yet, how the cell precisely choreographs these chromosomal interactions is a long-standing question.New findings by University of California, Berkeley, scientists show that the cell's cytoskeleton, which moves things around in the cell, plays a critical role, essentially reaching into the nucleus to bring...
U.S. geneticists say that for the first time ever they have successfully managed to induce human embryonic stem cells to transform into germ cells capable of producing egg and sperm cells "” a discovery that not only illuminates a previously ill-understood phase of human development but one that also carries practical potential for the treatment of infertility. Dr. Renee Riejo Pera of Stanford University in California explained that getting back to the earliest phases of human life and...
Advance provides potential tool to find causes of unexplained infertility, birth defectsResearchers funded in part by the National Institutes of Health have discovered how to transform human embryonic stem cells into germ cells, the embryonic cells that ultimately give rise to sperm and eggs. The advance will allow researchers to observe human germ cells"”previously inaccessible"”in laboratory dishes."This achievement opens a new window into what was only recently a hidden stage of...
A Florida State University scientist says he's found the cause of chromosomal birth defects, such as Down, XYY, Edwards, Patau and Turner's syndromes. Using yeast genetics, Assistant Professor Hong-Guo Yu and colleagues selectively removed a single protein from the cell division process called meiosis and found that when the protein known as Pds5 is missing, chromosomes fail to segregate and pair up properly, and birth defects can result. Researchers said the study shines new light on the...
