The egg makes sure that sperm don't get too old

Mar 25, 2009

In contrast to women, men are fertile throughout life, but research at the Sahlgrenska Academy, University of Gothenburg, Sweden, has now shown that a fertilising sperm can get help from the egg to rejuvenate. The result is an important step towards future stem cell therapy.

The risk of in the foetus is highly correlated to the age of the mother, but is nearly independent of the age of the father. One possible explanation is that egg have a unique ability to reset the age of a sperm.

"We are the first to show that egg cells have the ability to rejuvenate other cells, and this is an important result for future stem cell research", says Associate Professor Tomas Simonsson, who leads the research group at the Sahlgrenska Academy that has made this discovery.

Each time a cell divides, the genetic material at the ends of the chromosomes becomes shorter. The ends of the chromosomes, known as "telomeres", are important for the of the cell and they act as a DNA clock that measures the age of the cell. The cell stops dividing and dies when the telomeres become too short.

The discovery that the egg cell can extend the telomeres of a fertilising is important in the development of . Stem cell therapy involves replacing the in unfertilised egg with a nucleus from a somatic cell that has come from a patient who needs a . As soon as the cell has divided a few times, it is possible to harvest stem cells that are then allowed to mature to the cell type that the recipient needs.

"The genetic stability of the transplanted cells has been a serious concern up until now, and it was feared that the lifetime of these cells would depend on the age of the cell nucleus that was transferred. Our results suggest that this is not the case", says Tomas Simonsson.

Stem cell therapy

Stem cell therapy is based on the transfer of cells to replace cells that have become diseased or died. Reprogrammed stem cells have so far only been used in animal experiments. Much research remains to be done, but it is considered to be only a question of time before stem cell therapy becomes a possible treatment for diseases such as Parkinson disease, diabetes type I, muscular dystrophy and hereditary immune deficiency.

Source: University of Gothenburg (news : web)

Explore further: New knowledge about host-virus coevolution unmasked from the genomic record

add to favorites email to friend print save as pdf

Related Stories

Scientists create new cloning method

Oct 04, 2006

U.S. scientists say they have achieved a one-step somatic cell nuclear transfer procedure using a differentiated cell as a nuclear donor.

Recommended for you

Devising a way to count proteins as they group

6 hours ago

A new study from Indiana University-Purdue University Indianapolis and University of California Berkeley researchers reports on an innovative theoretical methodology to solve "the counting problem," which is key to understanding ...

Mysteries of 'molecular machines' revealed

7 hours ago

"Inside each cell in our bodies and inside every bacterium and virus are tiny but complex protein molecules that synthesize chemicals, replicate genetic material, turn each other on and off, and transport ...

Bacteria are wishing you a Merry Xmas

13 hours ago

A bacterium has been used to wish people a Merry Xmas. Grown by Dr Munehiro Asally, an Assistant Professor at the University of Warwick, the letters used to spell MERRY XMAS are made of Bacillus subtilis, ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.