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Eggs 'tricked' into becoming embryos

2 December 2004
By BioNews
Appeared in BioNews 287

A method for persuading human eggs to start dividing as though they have been fertilised could provide a less controversial source of embryonic stem cell (ES cells), say UK researchers. The scientists, based at the University of Wales in Cardiff, also say that the technique might help improve the success rate for couples undergoing ICSI (intracytoplasmic sperm injection) treatment.

The researchers, who published their findings in the journal Reproduction, have discovered that human eggs injected with a substance called phospholipase C-zeta (PLC-zeta) will start dividing. PLC-zeta is a protein produced by sperm, discovered by the Cardiff team two years ago, New Scientist magazine reports. The injected eggs will grow for about 4-5 days, until they reach the 50-100 cell blastocyst stage of development. Because they only contain genes from the mother, such 'parthenogenetic embryos' could never develop further, but they could still be used as a potential source of ES cells.

Many scientists believe that ES cells hold great promise in the treatment of a wide range of diseases, since they can grow into any type of body tissue. However, human ES cell research is controversial, since it involves the destruction of embryos. Several groups are trying to find ways of growing ES cells without using embryos, either by creating parthenogenetic 'embryos', or using other approaches.

Last week, US scientist William Hurlbut, who opposes embryo research, said it should be possible to create cloned human embryos that are incapable of growing a placenta. Since 'embryos' created using this 'altered nuclear transfer' technique would not be able to develop into a fetus, Hurlbut believes it could provide a way for American scientists to create new human ES cells with government funding. The use of federal funds for stem cell research involving the destruction of embryos has been prohibited by Bush since 9 August 2001.

The leader of the latest study, Karl Swann, hopes that his team will be the first to obtain ES cells from human parthenogenetic blastocysts. However, some pro-life groups might still object to this research. 'I'd be happier if it was beyond all reasonable doubt that it could not become a human life', said Josephine Quintavalle of Comment on Reproductive Ethics (Core). She added that women must not be exploited to provide eggs for this purpose.

PLC-zeta could also help couples undergoing ICSI, a fertility treatment in which a single sperm is injected into an egg in the laboratory. Embryos produced in this way do not always start dividing and growing, possibly because the sperm has defective PLC-zeta. Adding some of this substance could overcome this problem, say the scientists.

Eggs 'fertilised' without sperm
BBC News Online |  2 December 2004
Spark of life creates 'ethical embryos'
The Scotsman |  2 December 2004
Zapped human eggs divide without sperm
New Scientist |  1 December 2004
16 May 2005 - by BioNews 
The US President's Council on Bioethics has published a report on alternatives to human embryonic stem (ES) cells, which do not involve the destruction of embryos. The document, entitled 'Alternative sources of pluripotent stem cells', looks at ways of extending the number of cell-lines available to federally funded stem cell...
6 December 2004 - by Dr Kirsty Horsey 
Recent news reports have highlighted the fact that scientists are searching for a way to create human embryonic stem (ES) cells without destroying human embryos. Normally, the derivation of ES cells requires that the embryo they came from be destroyed in the process. Many people have no ethical problem with...
24 November 2004 - by BioNews 
An American bioethicist has claimed that it is possible to create cells equivalent to embryonic stem (ES) cells without creating an embryo. Dr William Hurlbut, from Stanford University, says that it is possible to using somatic cell cloning technology to create something that could never become an embryo, therefore avoiding...
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