Fw:Embyos without paternal chromosomes now possible

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Saturday, December 04, 2004 10:32 AM

Embyos without paternal chromosomes now possible

 

 

This is probably one of the final insults to God. N

 

http://www.rumormillnews.com/cgi-bin/forum.cgi?read=60567

 

ZAPPED HUMAN EGGS DIVIDE WITHOUT SPERM

 

Posted By: Seidr <Send E-Mail>

Friday, 3 December 2004, 4:58 a.m.

 

Journal reference: Reproduction (vol 128, p 697)

 

by Andy Coghlan

 

A trick that persuades human eggs to divide

as if they have been fertilised could provide

a source of embryonic stem cells that sidesteps

ethical objections to existing techniques.

 

It could also be deployed to improve

the success rate of IVF.

 

" Embryos " created by the procedure do not contain

any paternal chromosomes -

just two sets of chromosomes from the mother -

and so cannot develop into babies.

 

This should remove the ethical objections

that some people have to harvesting from

donated human embryos.

 

There are high hopes that stem cells,

which can develop into many different cell types,

could be used to treat a range of diseases.

 

The tricked eggs divide for four or five days

until they reach 50 to 100 cells -

the blastocyst stage.

 

These blastocysts should in theory yield stem cells,

but because they are parthenogenetic -

produced from the egg only -

they cannot be viewed as a potential human life,

says Karl Swann of the University of Wales College

of Medicine in Cardiff, UK.

 

" This could eliminate one of the main sources

of ethical controversy in this research, "

says Bob Lanza, head of research at the cloning company

Advanced Cell Technology in Worcester, Massachusetts.

 

But Josephine Quintavalle of

Comment on Reproductive Ethics,

a London-based pro-life lobby group

greeted the new procedure with caution.

 

" I'd be happier if it was beyond all

reasonable doubt that it could not

become a human life. "

She added that women must

not be exploited to provide eggs.

 

" Spark of life "

 

Swann's team tricked the eggs into dividing

by injecting phospholipase C-zeta (PLC-zeta),

an enzyme produced by sperm that

Swann discovered two years ago

with Cardiff colleague Tony Lai.

 

" It's the spark of life, " says Swann,

who has previously showed that the human version

of the protein can trigger mouse eggs to develop

into blastocysts.

" It tricks the egg into thinking it has been fertilised. "

 

Human eggs contain two sets of chromosomes,

one of which is normally jettisoned

within two hours of fertilisation.

 

Swann and his team used a standard

chemical treatment to prevent this,

so both sets in the parthenogenetic embryos

come from the mother.

The embryos appear to undergo the same changes

as naturally fertilised eggs,

producing waves of calcium ions across

the cell every 20 to 30 minutes.

 

MORE ARTICLE AT LINK:

 

 

http://www.newscientist.com/news/news.jsp?id=ns99996733