Permission To Create Chimeras, Not Hybrids, For Stem Cell Research

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Permission To Create Chimeras, Not Hybrids, For Stem Cell Research

http://www.medicalnewstoday.com/healthnews.php?newsid=56266

A chimera is an organism which has two or more genetically different

groups of cells that originate from different organisms. A hybrid is

a being made from the egg of one species and the sperm of another. A

mule is a hybrid of a donkey and a horse.

Scientists from Newcastle University, UK, and Kings College, London,

UK, want to get cows' eggs and place human nuclei inside them. They

say it is a route for creating stem cell lines. They say this

research would help us better understand and cure diseases. It could

eventually lead to the creation of organs for transplant. The

application has been submitted to the Human Fertilisation and

Embryology Authority (HFEA ) for a three-year licence.

This route would free scientists from using donated human eggs.

Chimeras of the same species can exist. However, the scientists seek

permission to create non-human oocytes. The stem cells they would

like to create would be 99.9% human and 0.1% animal. The animal's

egg would have no nucleus, but would contain minute quantities of

mitochondrial DNA. The animal's egg would mix with human nuclei, a

chimera oocyte would be formed and the stem cells harvested after a

few days. In other words, imagine using just the shell of, say, a

cows' eggs to hold the human nuclei.

(Oocytes = Eggs whose nuclei have been removed)

As it is impossible to carry out experiments on humans, this

procedure could be used for this, say the scientists.

Dr Minger, King's College London, said " What we are

proposing to do is not really create chimeras but rather use non-

human oocytes merely as a surrogate to generate human embryonic stem

cell lines from individuals with genetic forms of neurodegenerative

diseases. " Minger and team aim to use this technology to research

Alzheimer's and Parkinson's disease.

Dr Lyle Armstrong, University of Newscastle said " We are very

hopeful that the HFEA will grant us permission for this work, which

will help us to understand more about how cells behave after the

nuclear transfer process. We need this information to enable us to

take this area of stem cell research to the next stage. At the

moment we don't know if the nuclear transfer process works well

enough in humans to create useful embryonic stem cells. We need to

carry out many tests to establish this and, as animal eggs are

freely available, it makes sense to use these as a source of

material for our laboratory work.... Stem cell research promises

huge potential medical advantages and we believe we will be working

towards our ultimate goal of developing new patient therapies. "