Oocyte in Biological News

December 2008 highlights from Biology of Reproduction

... If follicles fail to form, the result is oocyte demise, yet oocytes are also essential for ... Several factors key to follicular formation and oocyte survival have been discovered recently, such as ... 2) is crucial for follicular development and oocyte survival. Although some primordial follicles ...

Rong Li Lab probes mechanism of asymmetry in meiotic cell division

... protein called formin-2. This protein allows the oocyte to retain the majority of the cytoplasm a ... defects are often related to problems during oocyte meiotic cell divisions," said Rong Li, Ph.D., ... in the chromosome movement will lead to failed oocyte maturation and infertility. These findings ...

Stowers Institute's Hawley Lab identifies factors responsible for restart of meiotic cycle

... egg, allowing for production of a mature oocyte ready for fertilization. The findings appear in ... by the Hawley Lab in this work. In the fruit fly, oocyte development is arrested for 3-4 days at exactly ... it raises the question of just how the sleeping oocyte is reawakened. The Hawley Lab addressed this ...

A unique arrangement for egg cell division

... of its progenitor cell, the oocyte. Unlike other cells in the body, an oocyte does not divide equally to produce two identical daughter cells. Instead, ... themselves to the chromosomes, separate them and pull one half out of the oocyte into a small polar body that is later discarded. Microtubule spindles are ...

Ovarian transplantation: New technique gives greatly improved results in this delicate operation

... St. Louis Infertility Centre, St. Louis, Missouri, USA, said that freezing tissue by the vitrification method, which avoids ice formation, meant that oocyte (egg) viability was almost identical with that seen in fresh oocytes. Dr. Silber and colleagues used standard viability testing with fluorescent ...

Who goes abroad for fertility treatment and why?

... already gathered by patient support groups and reported in the media. For example, Spain and the Czech Republic are popular destinations for oocyte donation; Swedes travel to Denmark for insemination, and French to Belgium. "It has also enabled us to have concrete proof of the large ...

ESHRE launches international study of polar body screening

... be completed within a time period that allows for fresh transfer, as well as to ensure the reliable identification of the chromosomal status of an oocyte in at least 90% of polar body biopsy attempts." The two centres chosen for the pilot study have considerable experience in the field of polar ...

Universitat Autonoma de Barcelona researchers first to clone mice in Spain

... seem to contribute to an increase in levels of gene expression, which would favour the reprogramming of the somatic cell nucleus transferred to the oocyte cytoplasm. Its use in nuclear transfer processes however is very recent. It was first used two years ago and research until now has focused on ...

Animal eggs not suitable substitutes to produce stem cells

... to become any type of somatic cell and used for cell or tissue repair or placement therapy. This extensive reprogramming requires that the oocyte turn on, or up-regulate a large number of genes in the donor nucleus. Although previous reports have documented the formation of cloned embryos ...

IVF does not increase risk of developmental disorders in children

... are stimulated with hormones to produce multiple oocytes (egg cells)) and 57 singletons born following IVF/ICSI in a modified natural cycle of oocyte production, where the one egg cell which develops naturally is utilised. In this latter method, the need for hormonal medication is much reduced, ...

New egg freezing technique offers hope to hundreds of women

... the various aspects of the problem of human oocyte cryopreservation. Using this method, we achieved ... survival rates for oocytes of 90-95%, making oocyte cryopreservation a real option for women. ... in egg freezing had grown. "Even although oocyte freezing is still considered experimental by the ...

FSU biologists uncover mechanisms that shape cells for better or worse

... activation in the cells surrounding the fruit fly oocyte acts to turn off a gene known as Dystroglycan, ... EGFR must shut down Dystroglycan in order for the oocyte to properly polarize," Poulton said. "We ... in the EGFR pathway of cells surrounding the oocyte led to abnormally high levels of Dystroglycan ...

Israeli scientists successfully transplant frozen-thawed ovaries in sheep

... adhesions and it was not possible to attempt oocyte collection, but two yielded one oocyte each and repeat aspiration four months later ... that the transplanted ovary contained small oocyte follicles, and although a little smaller than the ...

Scientists clone mice from adult skin stem cells

... Li took unfertilized mouse oocytes and replaced the nucleus of each oocyte with a nucleus from these adult skin stem cells. A main hurdle in ... cells and also with cumulus cells ?the cells that surround a developing oocyte and have traditionally been the preferred cell type for nuclear transfer. ...

SuperLigands - a database of ligand structures derived from the Protein Data Bank

... the patients' cells, Science authors reported. oocyte donors and patients who donated non-reproductive ... international oversight and ethical issues in oocyte donation, including the need to promote realistic ... paper resulted from nuclear transfer in which the oocyte and non-reproductive ("somatic") cell came from ...

Scientists generate patient-specific stem cells, Science study says

... the patients' cells, Science authors reported. oocyte donors and patients who donated non-reproductive ... international oversight and ethical issues in oocyte donation, including the need to promote realistic ... paper resulted from nuclear transfer in which the oocyte and non-reproductive ("somatic") cell came from ...

Heavy smoking cuts women's chance of pregnancy -- even with donated oocytes

... in non-heavy smokers (under 10 cigarettes a day) and 44 in heavy smokers (over 10 a day). None of the women's partners were smokers and none of the oocyte donors were heavy smokers. The two groups of recipients were comparable and the number of embryos transferred in each cycle (between one and three) ...

Component in soy products causes reproductive problems in laboratory mice

... are spread too thin and they can't get the support they need to become a mature functioning egg cell." "You need at least one good healthy single oocyte that is ovulated and fertilized by a sperm to get a healthy baby. Genistein seems to have a way of making this task very difficult," said Newbold. ...

Human Eggs Can Develop From Ovarian Surface Cells In Vitro

... genetic alterations, which are often associated with an advanced maternal age. In addition, a colonization of premenopausal ovaries with younger oocyte and granulosa stem cells may establish a new cohort of primary follicles. This may result in a 10- to 12-year delay of the onset of natural ....