Dad's sperm delivers more than DNA

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http://www.cbc.ca/stories/2004/05/12/sci-tech/sperm040512

 

C B C . C A N e w s - F u l l S t o r y :

 

Dad's sperm delivers more than DNA

Last Updated Wed, 12 May 2004 20:35:54

LONDON - Human sperm deliver more than male chromosomes to an egg, a new study

suggests.

Scientists had thought sperm deliver DNA only, with the fertilized egg steering

development from there.

 

Sperm deliver RNA that may help embryo development

Now researchers in the U.S. and Britain have shown sperm also deliver messenger

RNA, which may carry codes that help the embryo grow and develop.

" Men have a greater role in early development than we previously thought, " said

Stephen Krawetz, head of the team at Wayne State University in Detroit.

Krawetz and his colleagues identified six messenger RNAs in human sperm and

fertilized eggs that are not present in unfertilized eggs. The difference

implies sperm deliver the molecules to the egg at fertilization.

Two of the RNA molecules carrying instructions for the proteins protamine-2 and

clusterin made it into the egg. Clusterin is thought to enhance fertility and

embryonic development.

If the role of the molecules in confirmed, it may explain why cloning techniques

that transfer DNA only have such a low success rate. The findings could also

help infertility researchers.

In April, researchers in Japan and South Korea reported the birth of a mouse

with all-female DNA.

" In contrast, we show that men are not obsolete, " Krawetz said in release.

The study appears in Thursday's issue of the journal Nature.

 

 

Written by CBC News Online staff

 

 

2004 Canadian Broadcasting Corporation -

 

 

 

 

 

 

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