Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


‘Genetic biopsy’ of human eggs might help pick the best for IVF

Researchers at Brown University and Women & Infants Hospital of Rhode Island have developed a way to extract information about gene expression from fertile human egg cells without hurting them. Expendable ‘polar bodies’ in the cells reflect much the same information as the eggs themselves, researchers have determined.

Given the stakes of in vitro fertilization, prospective parents and their doctors need the best information they can get about the eggs they will extract, attempt to fertilize, and implant. New research at Brown University and Women & Infants Hospital of Rhode Island has found a way to see which genes each egg cell is expressing without harming it.

As researchers learn more about how those genes affect embryo development, the new technique could ultimately give parents and doctors a preview of which eggs are likely to make the most viable embryos.

In the research, now in press in the Journal of Biological Chemistry, the team of physicians and biologists was able to sequence the transcribed genetic material, or mRNA, in egg cells and, in a scientific first, in smaller structures pinched off from them called “polar bodies.” By comparing the gene expression sequences in polar bodies and their host eggs, the researchers were able to determine that the polar bodies offer a faithful reflection of the eggs’ genetic activity.

Polar bodies allow “a natural cytoplasmic biopsy,” providing genetic information without hurting the egg cell.“We can now consider the polar body a natural cytoplasmic biopsy,” said study co-author Sandra Carson, professor obstetrics and gynecology at the Warren Alpert Medical School of Brown University and director of the Center for Reproduction and Infertility at Women & Infants Hospital.

Polar bodies are where egg cells dispense with the second copies of chromosomes that, as sex cells, they don’t need. But the polar bodies also capture a microcosm of the egg’s mRNA, the genetic material produced when genes have been transcribed and a cell is set to make proteins based on those genetic instructions.

Pairs of genes

Last year the team became the first to find mRNA in human polar bodies. Now they have transcribed it in 22 pairs of human eggs and their polar bodies, and confirmed that what is in the polar bodies is a good proxy for what is in the eggs.

Given how little mRNA is present in polar bodies, the task was not easy, said Gary Wessel, professor of biology, but through a combination of clever amplification and analysis techniques by lead author and graduate student Adrian Reich and second author Peter Klatsky, the team got it done.

“There’s no reason this should have worked, just because there was so little material,” Wessel said. “Single-cell sequencing is very challenging.”

To hedge their bets the team analyzed most of the samples in two pools of 10 cells each, for instance comparing the mRNA in 10 eggs with the mRNA in the 10 related polar bodies. But to their pleasant surprise, they were also able to sequence two individual eggs and their polar bodies directly.

What they found is that more than 14,000 genes can be expressed in the eggs. Of those, more than 90 percent of the genes detected in the polar bodies were also detected in the eggs and of the 700 most abundant genes found in the polar bodies, 460 were also among the most abundant in the eggs.

The team devised a way to get maximum information from a small amount of genetic material. “There’s no reason this should have worked.”Toward clinical use

“It seems that the polar body does reflect what is in the egg,” Carson said. “Because the egg is the major driver of the first three days of human embryo development, what we find in the polar body may give us a clue into what is happening during that time.”

But Carson and Wessel acknowledged that more research will be required to create a clinically useful tool.

Finding which genes affect embryo viability is the next major step. With the new knowledge and techniques developed in their study, the researchers said, scientists could analyze the mRNA from polar bodies of eggs that are fertilized and track the progress of the resulting embryos. Once the key genes are known, they could create fast assays to look for those genes in polar bodies so that clinicians and patients could pick the best eggs. A sufficiently developed technology could also be used for choosing which eggs to bank for later use.

“We don’t quite have the answer of what those messages are doing exactly or necessarily the purpose of them in the cell function, but that’s to come,” Carson said. “Now we have the words, but not the sentences.”

The research was funded by seed grants from the Brown University Office of the Provost, the Center of Excellence in Women’s Health of Women & Infants Hospital, and Sigma-Aldrich, a research reagent supplier.

Editors: Brown University has a fiber link television studio available for domestic and international live and taped interviews, and maintains an ISDN line for radio interviews. For more information, call (401) 863-2476.

David Orenstein | EurekAlert!
Further information:

More articles from Life Sciences:

nachricht Make way for the mini flying machines
21.03.2018 | American Chemical Society

nachricht New 4-D printer could reshape the world we live in
21.03.2018 | American Chemical Society

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

In just a few weeks from now, the Chinese space station Tiangong-1 will re-enter the Earth's atmosphere where it will to a large extent burn up. It is possible that some debris will reach the Earth's surface. Tiangong-1 is orbiting the Earth uncontrolled at a speed of approx. 29,000 km/h.Currently the prognosis relating to the time of impact currently lies within a window of several days. The scientists at Fraunhofer FHR have already been monitoring Tiangong-1 for a number of weeks with their TIRA system, one of the most powerful space observation radars in the world, with a view to supporting the German Space Situational Awareness Center and the ESA with their re-entry forecasts.

Following the loss of radio contact with Tiangong-1 in 2016 and due to the low orbital height, it is now inevitable that the Chinese space station will...

Im Focus: Alliance „OLED Licht Forum“ – Key partner for OLED lighting solutions

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, provider of research and development services for OLED lighting solutions, announces the founding of the “OLED Licht Forum” and presents latest OLED design and lighting solutions during light+building, from March 18th – 23rd, 2018 in Frankfurt a.M./Germany, at booth no. F91 in Hall 4.0.

They are united in their passion for OLED (organic light emitting diodes) lighting with all of its unique facets and application possibilities. Thus experts in...

Im Focus: Mars' oceans formed early, possibly aided by massive volcanic eruptions

Oceans formed before Tharsis and evolved together, shaping climate history of Mars

A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...

Im Focus: Tiny implants for cells are functional in vivo

For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.

In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Virtual reality conference comes to Reutlingen

19.03.2018 | Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

Latest News

Taming chaos: Calculating probability in complex systems

21.03.2018 | Physics and Astronomy

Researchers at Fraunhofer monitor re-entry of Chinese space station Tiangong-1

21.03.2018 | Physics and Astronomy

New 4-D printer could reshape the world we live in

21.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>