WHAT sort of person would you get if you crossed the genes of Marilyn Monroe with those of, say, Madonna? Till now such a hypothetical question would rightly have been greeted as a little crazy. But the age-old certainty that two females cannot sexually reproduce has been demolished (see 鈥淒awn of a new kind of parenthood鈥�).
Crossing two female mice to produce a daughter with two mums and no dad is one of those rare scientific firsts that are genuinely unexpected and amazing. Until now dogma has held that the union of egg with egg will never bear fruit. But tweak just a couple of genes in one of the eggs, we now learn, and the union works. What is achieved is a sort of masculinising sex change for the egg.
Could it work in humans? Some researchers will dismiss such a suggestion as mischievous hype. The methods used to create this mouse, they will point out, were inefficient, involved many failed pregnancies, and relied on genetic engineering that is taboo in humans. Moreover, while Kaguya looks to be in fine fettle, there is no proof she is completely normal.
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All of which is true. But that is no reason to dodge questions about the relevance to people. When Dolly the sheep hit the headlines in 1997, it was right to ask what it meant for humans and whether new laws were needed to regulate research. This time the questions are even more compelling.
When Dolly was born, scientists at least knew what to call the technique: cloning. By contrast, the ability to create offspring, sexually, from two mammalian eggs is so lacking in precedent that science does not even have a word for it. Some classify it as parthenogenesis 鈥� the name traditionally reserved for the development of a single egg into an embryo unaided by sperm. But this fails to capture the sexual dimension. A new word is required 鈥� 鈥渉omoparentism鈥� perhaps.
Such a term would emphasise the crucial difference between Kaguya and Dolly. The primary objection to cloning humans is that present techniques are too inefficient and potentially hazardous to the health of any offspring. The same would certainly be true of trying the Kaguya technique on people.
Yet many of the secondary objections people have to cloning would not apply. The offspring of two women would be genetically distinct, not the copy of an older person. Sexual recombination, and with it individuality, would still be part of the recipe. So there is a case for seeing Kaguya as a more natural creation than Dolly.
Our expertise may never advance to the point where human Kaguyas can or should be born. But we cannot ignore the possibility that it might. The leader of the Japanese team says it is senseless to ask whether his breakthrough could apply to humans. With respect, Professor Kono, it would be senseless not to ask.