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Posted on 09/06/2006 10:20:53 AM PDT by PatrickHenry
The human egg’s ability to transform into a new life, or into new cells that may someday save lives, is well documented. The mystery lies in the mechanics – in how a single cell can transform so nimbly.
Scientists at Michigan State University report this week in the Proceedings of the National Academy of Sciences that they have identified genes unique to the human egg. The identification opens the way to understanding these genes’ functions, which may lead to solving problems from infertility to degenerative diseases.
“What’s in the egg to have that power?” asked Jose Cibelli, MSU professor of physiology and animal science. “Some of those genes are responsible for the magic trick that the egg has. This paper takes a peek at what genes are in the egg waiting to make these changes.”
Combined with sperm, the egg divides and organizes cells to ultimately create a human being.
Combined with technology, the unfertilized egg might be coaxed to produce other specific cells, including stem cells, which can be directed to grow into new tissue. This potential could be used to combat diseases.
Cibelli said his team’s mission is to grow stem cells without using fertilized embryos, which can be controversial. This work used only unfertilized human eggs that were obtained from women seeking fertility treatment at a clinic in Santiago, Chile. Women at the clinic must be reproductively healthy, no older than 35, and the cause of infertility must lie within the man. This presented the availability of exceptionally healthy eggs, Cibelli said. All the donors granted informed consent for their surplus eggs to be used for this research.
Cibelli worked with researchers in Chile to extract the RNA from the unfertilized eggs soon after they were harvested. That material, a treasure of genetic information, was frozen and shipped to MSU.
Cibelli’s team, Arif Murat Kocabas, Pablo Ross, Zeki Beyhan and Robert Halgren, started analyzing the thousands of genes represented in the human egg to identify those which are unique to the egg. They teamed with Beth Israel Deaconess Medical Center at Harvard Medical School in Boston to work with sophisticated bioinformatics software.
To make a comparison that would show which genes were uniquely active in the human egg, they used RNA of all parts of the human body – except that of the ovaries, where eggs are produced.
Then the computer analysis began. In a highly sophisticated game of match, every gene in the egg that was found in other tissues was eliminated, so that only unique genes remained.
Cibelli said that the team identified 5,331 human genes that are overexpressed in the egg. Of those, 1,430 are mysteries – their function unknown.
The group also compared the human egg genes with those of a mouse as well as human and mouse embryonic stem cells. On the final intersection, 66 genes were found to be common between the four sets of data.
“There are thousands of genes that are redundant. We found about one in a thousand genes that are unique to the eggs – and some of them, they don’t have a known function yet,” Cibelli said. “Now we can clone these genes and put them into cells and see if they may have a role in the creation of stem cells – without fertilization or destruction of human embryos.”
Cibelli believes some of those genes know the big secrets – such as when a cell should slow down and later become a cell that can grow into any cell of the human body. The computer work of this preliminary search will give way to further experiments.
This research was funded by the MSU Office of the Vice President for Research and Graduate Studies, and supported by the Michigan Agricultural Experiment Station.
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Michigan State University has been advancing knowledge and transforming lives through innovative teaching, research and outreach for 150 years. MSU is known internationally as a major public university with global reach and extraordinary impact. Its 14 degree-granting colleges attract scholars worldwide who are interested in combining education with practical problem solving.
Human cells do not have a cell wall. Do you mean the cell membrane?
If you wish. The outer lining of the cell. Membrane, whatever. Also the outer linings of the cell-like things inside the cell.
Oh, you bwute! You bwute! Imagine my little fists pummeling your smarmy, wude chest.
Moo U propaganda placemarker. I love it :-)
And once again, we prove your point (lucky your hat covers it). [Geez, am I funny or what?]
Why do the tentative words bother you? That's how science works.
Hypotheses are developed. They use words like "may" and "might."
Seriously, do you have a problem with science?
I have a problem with people, whether politicians, salesmen, or scientists, making exaggerated claims and predictions simply because they sound good.
Some scientist have made and are making unrealistic preditions about the speed with which therapies will be produced. Here is an article from last year, "Medical Value of Stem Cells 'Over-Hyped'", in which Robert Wilson, a professor of fertility studes at Imperial Colleg London, cautions "I think it is unlikely that embryonic stem cells are likely to be useful in health care for a long time."
In another article on the same subject, "Stem Cell Hopes Distorted by 'Arrogance and Spin'", it says that scientists are being over-optimistic and providing a "case study in scientific arrogance and the danger of 'spining' a good story."
Hypotheses in science are never proven. What a scientist can do is collect experimental data that supports the hypotheses. Einsteins theory of relativity has never been proven and can't be. Inductive reasoning from experimental is not a proof. All any one can say is that the data supports the hypothesis. Someone may come up with a better hypothesis later on. Indeed, Einstein spent the last 35 years of his life trying to find a unified field theory that would reconcile his theory with quantum mechanics. He failed.
But a predition of the speed with which therapies will be found is not a hypothesis. It is only a prediction, and not a very good one when it is done simply to get research money. What I am asking for is to cut the hype and be more realistic about what may be possible.
Their are huge obstacle to overcome. Scientists do not know the mechanisms to direct embryonic stem cells to specific types of cells. There is also some evidence to suggest that such adult cells could spontaneously revert back to stem cells, or start growing in distorted and unpredictable ways like a cancer.
And what about proper peer review? A Korean scientist faked cloning experiments and lots of people simply accepted the findings because they wanted them to be true. That is not good science by any stretch of the imagination.
Let's all just cool the hype.
Ah! Life!
...and since the egg is the woman's contribution -- it shows how early the woman is able to multitask. :-)
Cheers!
“There are thousands of genes that are redundant. We found about one in a thousand genes that are unique to the eggs – and some of them, they don’t have a known function yet,” Cibelli said. “Now we can clone these genes and put them into cells and see if they may have a role in the creation of stem cells – without fertilization or destruction of human embryos.”
All very intriguing, and promising line of inquiry -- hope it proves frutiful!
Placemarker
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