Male couples could one day conceive their own children using the genetic techniques applied to produce Dolly the cloned sheep, a UK scientist has claimed. The child would have two fathers but no genetic mother.
"It's theoretically possible, if they were able to control the implanting, to have a child that's born as a result of having two fathers," according to Dr Calum MacKellar, a lecturer in bioethics and biochemistry at Edinburgh University.
"I think it is realistic and I think we should think about it."
A surrogate mother would be needed to bring the child to full term, he said during an interview yesterday on BBC radio. However, a homosexual couple could use their own DNA to conceive the child.
Dolly was created using "nuclear replacement techniques", he said, and a similar approach could be used in this case.
A "male egg" would be created by removing the centre or nucleus from a donor egg and replacing this with the nucleus from a sperm cell.
The new egg would have male DNA and could then be fertilised in-vitro by another sperm before being implanted in the womb of a surrogate mother, according to Dr MacKellar, who runs a non-profit organisation called European Bioethical Research.
There were significant genetic obstacles currently preventing the idea becoming reality, he acknowledged.
The embryo of a mammal created using only male DNA would lack imprinted maternal genes which would allow it to develop normally, he said.
If this could be overcome, however, a male-only conception was theoretically possible.
The hurdles to such an event would be significant, according to Dr Dan Bradley of the Department of Genetics at Trinity College Dublin.
Quite aside from the enormous ethical issues raised, "I don't think that it would work," he said.
While the mother and father each contributed 23 chromosomes to conceive a child, these didn't come as equal shares, he said.
"The type of DNA is somewhat altered in each so they are not exactly equal."
Nature employed a technique called "genomic imprinting", a process whereby a gene's activity in the child varied depending on whether the gene was contributed by the father or by the mother. DNA from a male would be imprinted as male and a child conceived with male-only DNA would lack female imprinting.
"You need the complementarity of the two," Dr Bradley said.
Imprinting is a way of co-ordinating genetic activity, for example preventing duplicate genes from being switched on or both versions of a gene being switched off.
Some genetic disorders are caused when this process doesn't work well.
Scientists had already tried male-male conception using mice, Dr MacKellar said, but had not developed the work.
The British Parliament is about to vote on a Bill which would permit human cloning for therapeutic purposes. Male-only conception would be prevented under this legislation.
