The US Conference of Catholic Bishops have said that proposals by the National Institutes of Health (NIH) to authorise federally funded research on part-human, part-animal embryos are "grossly unethical."
The bishops made ethical and legal arguments in opposing the plan in a submission to the institute this week, saying that such research would result in "beings who do not fully belong to either the human race or the host animal species."
Current NIH guidelines for human stem cell research specifically prohibit introducing human pluripotent cells - those capable of giving rise to several different cell types - into nonhuman primate blastocysts, which are cells at an early stage of development.
