In parthenogenesis, an unfertilised egg keeps two sets of chromosomes and begins developing as if it had been fertilised. Some insects and reptiles can reproduce this way but even though an electric or chemical stimulus can induce parthenogenesis in mammals, the resulting embryos die after a few days.

And that, according to its proponents, is the beauty of the technique as far as stem cells are concerned: it produces embryos that could never become human beings. So destroying these embryos to obtain stem cells would avoid the ethical concerns that have led to restrictions or bans on embryonic stem cell research in many countries.

[...] A team led by fertility specialist David Wininger at biotech firm Stemron of Maryland has grown parthenogenetic human embryos to the blastocyst stage, at which stem cells can be obtained. Cells taken from one of the embryos survived for a few days.

[...] Since eggs are needed to make parthenogenetic stem cells, one potential problem is that the technique could not be used to make matching stem cells for men or for women after menopause. Therapeutic cloning, by contrast, could provide matching stem cells for any individual.

However, because cells made by parthenogenesis have two identical sets of chromosomes, rather than one set each from the father and the mother, they have less variation in the surface proteins on cells that can trigger immune reactions. Wininger thinks it will possible to establish a bank of parthenogenetic stem cells that could provide cells to suit most individuals. And such banks would be much cheaper than creating stem cells from scratch for each individual.

Man, the scifi satire just writes itself these days, doesn't it? Thanks to the Religious Right, we end up with effective biological immortality for young women only, with the ageing Falwells going to back-alley baby-in-the-woodchipper Y-chromosome organ farms.