Infertile Female Mice Produce New Gametes
A female is born with all of the eggs she will have for the rest of her life. At least this has been the standing belief before recent experiments with female mice. A Chinese team of scientists, led by Kang Zou and Ji Wu of Shanghai Jiao Tong University, have found evidence that female mice can produce new eggs later in life.
Germ line-cells, present during embryo formation, are the cells responsible for the production of oocytes, unfertilized eggs. The researchers scanned mouse ovaries for a protein that is only present in germ line cells called vasa homolog. They then isolated vasa homolog producing cells (germ line cells) and tagged them with green fluorescent protein. These GFP cells were injected into the ovaries of mice whose own eggs had been killed. Matings between these mice resulted in offspring who were tagged with GFP. These results suggest that the injected germ-line cells successfully produced new eggs in receiving females.
An expert on reproduction at the University of Kansas Medical Center, David Albertini, says the results might be due to oocytes injected into the ovaries with the germ line proteins by mistake. However he admits the result was “a pretty exciting observation." Whether the results were accurate or not it cannot be outright stated that the result would stay true to humans due to obvious physiological differences. But the implications the results may have for human infertility are very promising.
-Jillian O'Keefe (Group C)
Germ line-cells, present during embryo formation, are the cells responsible for the production of oocytes, unfertilized eggs. The researchers scanned mouse ovaries for a protein that is only present in germ line cells called vasa homolog. They then isolated vasa homolog producing cells (germ line cells) and tagged them with green fluorescent protein. These GFP cells were injected into the ovaries of mice whose own eggs had been killed. Matings between these mice resulted in offspring who were tagged with GFP. These results suggest that the injected germ-line cells successfully produced new eggs in receiving females.
An expert on reproduction at the University of Kansas Medical Center, David Albertini, says the results might be due to oocytes injected into the ovaries with the germ line proteins by mistake. However he admits the result was “a pretty exciting observation." Whether the results were accurate or not it cannot be outright stated that the result would stay true to humans due to obvious physiological differences. But the implications the results may have for human infertility are very promising.
-Jillian O'Keefe (Group C)
Update:
No more research has been done yet (this was a very recent study). Obviously these results will lead to more experiments with mice and maybe eventually human test subjects. Also, there were no serious side effects that the mice experienced.
A swedish scientist, Dr. Frisen, recently studied the regenerative capabilities of heart muscle cells. Through carbon dating he was able to determine that heart muscle cells DO regenerate at a rate of less than 1 percent per year. Heart muscle tissue was thought to be like oocytes, you only have the cells you were born with. There are not enough oocytes in a persons body to provide a strong enough signal for carbon dating. But Dr. Frisen is hoping to find oocytes' birthday when his technique becomes more sensitive.
posted by PWH @ 6:49 PM
5 comments
5 Comments:
Interesting. It makes sense that if you inject mouse ovaries with the cells that produce the right chemicals for formation of oocytes, you will probably get oocytes. Sounds a little dubious though, given the observation that the resulting oocytes might actually have come about because they accidentally put oocytes in the ovaries.
[Nathan Beck, Group A]
After learning females are born with all of the eggs that she will ever have, it is hard to comprehend new eggs being produced. After this research, did the scientists ever challenge David Albertini's comments with extended research?
Shonneau Lippett
Jillian,
Very interesting blog! On a personal note: I disagree with the statement that the implications the results may have for human infertility are very promising. Considering the fact that we are dealing with a completely different species (mice), I believe that injecting germ-line cells in humans may lead to a considerable amount of harmful technicalities. Have researchers conducted further research into the side affects of this procedure?
Saad Choudhry
human infertility seems to be a big problem these days.. i wonder if it has to do with all the toxins in the air.. Has there been any research about humans being injected with these cells.. thats an avenue to explore.
Rachael Carlevale
This is some great news for future couples that cannot have children. It shows that in the distant future there may be a chance to have ovaries produce more eggs. How do you feel about the moral issues involved in the artificial initiation of egg production (if ever possible)?
-Calin Darabus
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