BERLIN—Mice carrying human genes are ethically acceptable, but German scientists who want to make transgenic monkeys with human genes should get permission from a national ethics panel, according to recommendations issued today by the German Ethics Council. The report , which addresses the ethics of human-animal mixtures, recommends that certain practices be forbidden: introducing animal material into the human germline, experiments that would lead to the development of human sperm or eggs in an animal, and implanting an animal embryo into a human.
Putting human brain cells into animals should receive special attention from the ethics panel that approves animal experiments, the report says. And scientists should look for better ways to measure the effects of such cells on the recipients' behavior.
German Basic Law, which functions as the country's constitution, states that "human dignity is inviolable," and the report delves deeply into the philosophical issues that arise when experiments mix animal and human cells or genes: How to define what is human, what counts as "animal," and whether mixing the two violates the dignity of either one. The report's philosophical slant—it cites Aristotle, Kant, Hans Jonas, and others—gives it a slightly different flavor from one issued by the British Academy of Medical Sciences  in July. That report came to similar conclusions, but based its recommendations on what the panel thought the British public would find objectionable. "They take a much more pragmatic approach," says geneticist and ethics council member Jens Reich.
The council failed to reach consensus on the creation of so-called cybrids, in which the nucleus of a human cell is inserted into an animal oocyte. Some researchers have tried to create early embryos using this technique, with the goal of making embryonic stem cell lines. Although Germany has laws forbidding both human cloning and research that harms human embryos, neither one covers work with cybrids, the panel concluded. Thirteen members of the council said the technique should be allowed. Eleven recommended that it be banned.
The report comes as Germany is revamping its animal research regulations in accordance with new rules the European Union issued  last year. Those rules require countries to establish a national ethics board to oversee animal research, and the council recommends that the board include experts qualified to evaluate the ethics of human-animal mixtures. It also recommends that the government's annual report on animal research include a detailed account of projects involving human-animal mixtures.
The council hopes the report will also help prompt public discussion of the topic. Council member Jochen Taupitz, a bioethicist at the University of Mannheim, says he hopes it will help dispel some common misperceptions about human-animal mixtures. "We want to make it clear that not everything is as troubling or ethically problematic as it might seem at first glance," he told a press conference today.
The report strikes a fair balance between public accountability and burdening scientists with too many bureaucratic hurdles, says council member Stefanie Dimmeler, who studies cardiovascular regeneration at the University of Frankfurt. "I believe we found a good compromise."