ARTs in action in nonhuman primates: Symposium summary - Advances and remaining issues

Several key issues in nonhuman primate ARTs were highlighted by this symposium, or arose during discussions. In addition, as requested by the organizers, I have included a few of my own thoughts for consideration. It was claimed that nonhuman primate ARTs "are ready for propagation of selected genotypes." Certainly, there have been large improvements in ART success rates, but implantation rates after embryo transfer are still only about 20%, which is the same as for human ART [5], so there is considerable room for increases in primate ART efficiency. • The production of identical twins in rhesus monkeys remains problematic. Success would provide a boost to biomedical research involving nonhuman primates. There needs to be continued extension of nonhuman primate ARTs into addressing human disease problems, not only human infertility. • We need continued development of technologies supporting these studies, i.e., ES cell derived cells and tissues, gene chips, etc. • I think it is very desirable to support cooperative training and collaborations among primate researchers, especially those not located at the National Primate Research Centers. Supplying materials for those investigators, e.g., cryopreserved IVP embryos, will increase the amount of research that can be conducted with nonhuman primates without large increases in cost, so it becomes more cost-effective. • I would encourage the provision of collaborative grants, using (e.g.) the Cooperative Agreement UO1 mechanism, to support and stimulate interactive ART research projects with nonhuman primates. This could be via a joint NCRR/NICHD/GMS program to share the cost and broaden the research scope. • There is a great need for increased emphasis on funding for nonhuman primate ARTs. Most of the available research funding during the past two decades has gone to support studies with mice, and although much basic information has been generated in this way, very little has been accomplished that can be directly helpful to human ART. • Meetings like this symposium are invaluable and cost-effective. They bring together researchers from different areas of nonhuman primate biology and encourage collaborations. It would be productive to hold such meetings regularly, with NIH support. • There are a number of important research needs that remain to be addressed, some of which were not directly addressed in the symposium, including: (i) Development of protocols for in vitro maturation (IVM) of primate oocytes; this would be useful for ARTs in monkeys and for humans, e.g., PCOS patients. This approach could also avoid excessive ovarian stimulation that may impact oocyte quality and can disturb the reproductive cycle. (ii) Identification of non-invasive markers for oocyte and embryo quality. (iii) Development of chemically defined embryo culture media, i.e., without serum or serum proteins, which would avoid the potential introduction of serum-derived pathogenic organisms. This could be critically important for culture of ES cells. (iv) Obtaining genetic and physiological data on in vivo produced embryos to establish a normal database for improving IVP embryo quality; because this is not, and will not be, available for humans, use of the nonhuman primate can provide critically important information. (v) Unless there is a sudden reduction in the AIDS research emphasis on rhesus macaques, which appears unlikely, we urgently need to establish other nonhuman primate models for ARTs. This should be a priority both for scientists involved in ARTs and for the NIH. Finally, I suggest that we need to make greater efforts to educate the general public as well as the federal government about the value of nonhuman primates as models for human disease. This could make our work more appreciated and encourage more support for this important research area. © 2004 Bavister; licensee BioMed. Central Ltd.