A study published this morning by Robert Lanza's team at Advanced Cell Technology suggests that cybrids--a controversial attempt to create a cloned human/nonhuman embryo--may not even work.
What is a cybrid? The word is short for "cytoplasmic hybrid embryo." The idea is to use nuclear transfer or cloning to create a cloned embryo as a resource for stem cell research. But in the case of a cybrid, the human nucleus is transferred, not to an enucleated human egg, but to an egg from a cow or a rabbit.
Last year, the government of the United Kingdom, following a particularly nasty debate, passed legislation allowing researchers to create cybrids. No sooner had the legislation passed, however, that "induced pluripotency" became widely accepted as a technically easier way to achieve many of the goals that motivated scientists to want to create cybrids. Not just technically easier, of course, but morally easier, because induced pluripotency creates pluripotent stem cells without embryos--cybrid, cloned, or IVF.
Now comes the Lanza study, suggesting that the interplay between the human and nonhuman genes prevents the cybrid from developing at all, not even to the point of being useful for deriving pluripotent stem cells.
The whole cybrid question is intriguing theologically. Are they human, these strange entities that have human nuclear DNA but the mitochondrial DNA of a cow or a rabbit? For more on the religious and ethical questions, let me refer you to a statement that I helped to co-author, available through the International Society for Science and Religion. Sadly, the cybrid controversy marked a new low-point in the UK on the religion-science front, with the moral concerns of religious people often misconstrued as being anti-science. On the brighter side, the question of the cybrid challenges theology and ethics to engage research as it develops while asking the perennial questions, such as what does it mean to be human.