by Dr. Susan Daniel
Currently there are two methods that can be used to determine whether or not an egg contains the correct number of chromosomes. A small part of the egg called the polar body can be removed and tested or the egg can be fertilized and a cell from the resultant embryo can be taken out and checked. Both procedures are invasive and can result in damage to the egg or embryo.
Scientists at the University of Oxford reasoned that chromosomal abnormalities in eggs might cause changes in the cumulus cells that surround and communicate with them. They studied the activity of genes in cumulus cells from chromosomally normal and abnormal eggs. They found that 729 genes were expressed differently in cumulus cells that had surrounded eggs with abnormal numbers of chromosomes. Dr. Elpida Fragouli, a scientist at the University of Oxford and director of cytogenetics at Reprogenetics, UK explained that they are working to determine whether these genes might be used to develop a non-invasive test for chromosome abnormalities in oocytes.
“New, non-invasive test for chromosome abnormalities may also shed light on genetic origins of faulty eggs”. 6 July 2011. http://www.ivf.net/ivf/new-non-invasive-test-for-chromosome-abnormalities-may-also-shed-light-on-genetic-origins-of-faulty-eggs-o6055.html