Latest Meiosis Stories

(Ivanhoe Newswire) – Is your biological clock about to run out? While women have always thought they are born with all of the eggs they need, new research says, that’s not true! A compelling new genetic study tracing the origins of immature egg cells, or 'oocytes', from the embryonic period throughout adulthood adds new information to a growing controversy. The notion of a "biological clock" in women arises from the fact that oocytes progressively decline in number as females get...

A compelling new genetic study tracing the origins of immature egg cells, or 'oocytes', from the embryonic period throughout adulthood adds new information to a growing controversy A compelling new genetic study tracing the origins of immature egg cells, or 'oocytes', from the embryonic period throughout adulthood adds new information to a growing controversy. The notion of a "biological clock" in women arises from the fact that oocytes progressively decline in number as females get older,...

Gene Is Involved in Fanconi Anemia – Thale Cress as Model Organism Scientists of KIT and the University of Birmingham have identified relevant new functions of a gene that plays a crucial role in Fanconi anemia, a life-threatening disease. The FANCM gene is known to be important for the stability of the genome. Now, the researchers found that FANCM also plays a key role in the recombination of genetic information during inheritance. For their studies, the scientists used thale cress as a...

Researchers at the University of California, Davis have discovered a key tool that helps sperm and eggs develop exactly 23 chromosomes each. The work, which could lead to insights into fertility, spontaneous miscarriages, cancer and developmental disorders, is published April 13 in the journal Cell. Healthy humans have 46 chromosomes, 23 from the sperm and 23 from the egg. An embryo with the wrong number of chromosomes is usually miscarried, or develops disorders such as Down's syndrome,...

[ Watch the Video ] After more than a century of study, mysteries still remain about the process of meiosis—a special type of cell division that helps insure genetic diversity in sexually-reproducing organisms. Now, researchers at Stowers Institute for Medical Research shed light on an early and critical step in meiosis. The research, to be published in the Nov. 8, 2011 issue of Current Biology, clarifies the role of key chromosomal regions called centromeres in the formation of a...

In children with genomic disorders, often a gamete – egg or sperm – has gone disastrously awry with either a duplication or deletion of genetic material that results in physical and neurological problems for the subsequent child. Previous studies have identified a procedure called nonallelic homologous recombination, which occurs during meiosis or sexual cell division, as the event that most commonly occurs and results in this mistake in DNA. Researchers from Baylor College of...

Most cells rely on structural tethers to position chromosomes in preparation for cell division. Not so oocytes. Instead, a powerful intracellular stream pushes chromosomes far-off the center in preparation for the highly asymmetric cell division that completes oocyte maturation upon fertilization of the egg, report researchers at the Stowers Institute for Medical Research. Their findings illustrate how oocytes repurposed a dynamic cellular mechanism capable of generating considerable...

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...

The human genome is peppered with repeated DNA elements that can vary from a few to thousands of consecutive copies of the same sequence. During meiosis"”the cell division that produces sperm and eggs"”repetitive elements place the genome at risk for dangerous rearrangements from genome reshuffling. This recombination typically does not occur in repetitive DNA, in part because much of it is assembled into specialized heterochromatin. Other mechanisms that restrain recombination in...

Ovarian 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 specialized 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 children with conditions such as Down's syndrome,...