An advisory body to the Spanish Ministry of Health (MoH) is to investigate the part played by a Spanish scientist in experiments published in the May issue of the journal Human Reproduction. Carmen Mendoza, professor at the Department of Biochemistry and Molecular Biology of the University of Granada, is thought to have carried out research involving human oocyte nuclear transfer without permission, which is against Spanish law. The case highlights differences in the regulation of human fertility experimentation across Europe.

Immediately following publication of the article—which reports alternative methods for human oocyte nuclear transfer into enucleated oocyte cytoplasts, aimed at alleviating infertility due to deficient ooplasmic factors—the Commission on Assisted Reproduction (CNRA) announced that it had received no request from Mendoza to authorize the work and that it was opening an investigation into the issue. Javier Rey, the CNRA's general secretary, told Nature Medicine that although Spanish law allows research on gametes, it prohibits their use in creating pre-embryos (up to 14 days after fertilization). Ironically, as no attempts were made to fertilize the oocytes in the experiment, Mendoza's group could probably have obtained permission for the study if they had applied. They did not. “Mendoza has committed a grave law infringement and, accordingly, she or her department may be penalized,” he says.

Speaking to the Spanish media, Mendoza explained she had not requested authorization “because the human oocyte assays were not done in Spain but in Italy…so the CNRA had nothing to authorize.” She has demanded a public apology from the commission, saying, “If not, I'm prepared to sue.” She told Nature Medicine that the MoH has already opened proceedings against her, her department and the Faculty of Sciences of the University of Granada.

In the paper, the group writes that it made no attempt to test the fertilization ability and post-fertilization developmental potential of the reconstituted oocytes because the formation of human embryos for research purposes is banned by law in France and Spain, and is subject to strict regulation in Italy.

However, Mendoza says “that to take the research a step further” they have to search for places where laws are not prohibitive. The lead investigator of the group, Jan Tesarik, who is also Mendoza's husband, is now looking into the possibility of carrying out fertilization experiments of reconstituted oocytes in Brazil, because this country, he says, has no legal constraints on this type of research. Tesarik points out that he could also conduct these experiments in the UK.