Abstract

Reproduction is a unique physiological event in that it often involves the interaction of social, environmental as well as biological factors.⁷ Reproduction is also the essence of species survival. Comprehensive studies of reproduction and formulating detailed databases are therefore fundamental to conserving species, populations and, indirectly, the vitality of entire ecosystems. As a result, there has been an increasing wellspring of interest in developing a wider, more integrated approach towards understanding, monitoring, enhancing, or controlling reproduction.^2,4,6 The term “reproductive sciences” has evolved to advocate integrative research and cooperative, multidisciplinary studies that can more efficiently address wildlife management problems and promote more effective reproduction.⁸

Historically, there has been a problem with the general perception of reproductive biology—the discipline is poorly understood by colleagues in the wildlife and academic communities in species other than domestic livestock, laboratory animals and humans. One reason is that reproductive scientists working with wildlife species are often perceived as routinely prescribing “high-tech” assisted reproductive technologies (artificial insemination, in vitro fertilization, embryo transfer and even cloning) to “breed endangered species.”^1,5 However, for most species there is a lack of a fundamental knowledge base of the basic reproductive processes and factors (e.g., environmental, behavioral, nutritional) that impact on effective reproduction. Therefore, at its first working meeting, the AZA’s Reproductive Sciences Advisory Group (Repro SAG) identified the need to:

1.  Develop mechanisms to communicate and educate people regarding the importance of integrating appropriate disciplines and technologies in the reproductive sciences;

2.  Develop a collaborative network of people who are interested in supporting studies of reproductive sciences for wildlife species; and

3.  Liaise with AZA Taxon Advisory Groups (TAGs) and Species Survival Plans (SSPs) to identify and prioritize research needs and provide advice on appropriate technology availability and utilization.

The mission statement of the AZA Reproductive Sciences Advisory Group is “to provide technical advice as a clearinghouse of information in the reproductive sciences for AZA and network members; develop cooperative relationships with a network of scientific societies and expert collaborators relating to reproductive sciences in a diverse array of species; and coordinate, facilitate and monitor cooperative studies of the of AZA’s conservation and science programs in reproductive sciences.”

Among the goals that the Repro SAG plans to achieve in a 3-yr action plan is the development of a network referral service consisting of members with expertise in a variety of scientific disciplines and a diverse array of taxa. This would provide an informed and complete counsel that can be effective for advising the SSPs and TAGs on methods for correcting or treating non-reproductive animals, as well as for enhancing their reproductive performances. Effort will be made to identify specific TAG and SSP needs and priorities, translate results from relevant scientific research and communicate this information to the appropriate TAG and SSP representatives. An additional goal will be the enhancement of international communication and collaborations, which includes establishing a database on reproductive parameters and strategies in free-ranging animals and determining how this information can be effectively applied to captive populations. An important and timely function of the Repro SAG will be to provide AZA members and related organizations guidance from a panel of scientific experts that can advise and provide informed position statements on the validity, feasibility, and applicability of some of the more basic, e.g., artificial insemination (AI) or embryo transfer (ET), to more advanced reproductive technologies (e.g., sex-selection or cloning) to conservation programs for rare or endangered species. Finally, members of the Repro SAG will liaise with the newly formed AZA Biomaterials Banking Advisory Group (BBAG) chaired by Cathi Lehn (Wildlife Conservation Society, Bronx Zoo) to participate in discussions regarding the development of protocols and policies as they relate to the collection, storage, information processing (databasing), ownership and distribution of gametes, embryos, and tissues used in breeding programs, also known as genome resource banks.³

Although the general consensus of the Repro SAG is to shift the focus of their efforts and research to more of a practical and basic nature to genuinely assist TAG and SSP breeding programs, it is nevertheless clear that there is a growing need for the development of efficient and reliable techniques for assisting reproduction. This is especially true for those species (e.g., ruminants and swine) where governmental regulatory agencies are restricting the international transport of animals due to the unavailability of quarantine stations as well as the potential for disease transmission to livestock or indigenous wildlife. For this reason, the International Embryo Transfer Society (IETS) recently formed a new Parent Committee on Companion Animals, Non-Domestic and Endangered Species (CANDES). The goals of the IETS CANDES Parent Committee, whose membership is more international in scope and focused on the development of assisted reproductive technology (ART) in these species, are complementary to those of the AZA Repro SAG. Whereas the AZA Repro SAG will concentrate their efforts on defining the reproductive patterns and strategies of novel species and understanding how various factors (e.g., environment, genetics, nutrition, health, and behavior) contribute to the effective management of natural reproduction in captive populations, the IETS CANDES Parent Committee will use that groundwork to develop more efficient reproductive technologies (Figure 1). This will be accomplished either by modifying existing techniques developed for use in livestock, laboratory animals and humans, or by the design of completely unique methodologies. The IETS CANDES Parent Committee is organized as four subcommittees:

1.  Regulatory Subcommittee: Besides the health and safety concerns when transporting animal tissues, those who work with rare and endangered species have additional restrictions by federal (e.g., United States Fish and Wildlife Department) and international (e.g., CITES, Convention on International Trade of Endangered Species) agencies which are often ill-defined and inconsistent between countries. An important objective of this subcommittee is to assist in clearly defining conditions and requirements to facilitate and expedite the safe and legal transport of biological materials, while at the same time holding high standards to minimize the potential of inadvertent disease transmission, without unduly restricting technological advances in research and conservation programs.

2.  Research Subcommittee. The initial objective of this committee will be to compile information on existing protocols proven to be effective for applying assisted reproductive techniques for a diverse array of taxa with updates and new additions included on a regular basis. A future objective of this subcommittee will be to identify and prioritize critical areas in need of research to develop protocols for embryo transfer and related technologies in companion animals, non-domestic and endangered species.

3.  Technology Subcommittee. The goal of this subcommittee is to identify and prioritize important areas that need technological development to broaden the application of embryo transfer and related technologies in companion animals, non-domestic and endangered species.

4.  Health and Safety Subcommittee. This subcommittee will serve several important purposes including: 1) review literature on embryo or sperm and pathogen interactions in companion animals, non-domestic and endangered species (which is quite limited at present); and 2) identify studies on specific pathogen interactions with gametes or embryos that are in dire need of research and report these to the CANDES Research Subcommittee.

Figure 1

Schematic diagram illustrating the complementary goals and functions of the AZA Reproductive Sciences Advisory Group and the IETS CANDES Parent Committee and the ultimate benefit to population management

Owing to the potential benefit for both groups, the annual working meetings of the AZA Repro SAG and the IETS CANDES Parent Committee will be held jointly and in association with the International Symposia on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife. The 2nd symposium was held on 28–29 September 2002; free electronic copies of the proceedings (abstracts and lists of selected references) and information on future programs can be requested at: ARTSymposia@omahazoo.com. There will also be two special journal issues that will publish selected presentations from the more recent symposium: Zoo Biology (Karen Goodrowe, Guest Editor) and Theriogenology (Rebecca Krisher, Guest Editor). The programs for these symposia are designed by members of the AZA Repro SAG and the IETS CANDES Parent Committee to specifically meet the informational needs and reflect the interests of both groups.

In summary, the complementary goals of the AZA Reproductive Sciences Advisory Group and the IETS CANDES Parent Committee are certain to prove to be an important and valuable resource for zoo and wildlife veterinarians, managers and keepers to manage the reproductive performances of a diverse array of taxa. Natural reproduction can be enhanced by understanding species-specific factors that can influence fertility and either providing conditions that reflect those that are naturally found or attempting to mimic them artificially. Assisting reproduction should be perceived in its broadest sense, and that would be any initiative taken or stimulus introduced that can enhance reproductive function (e.g., changing light cycles or other environmental manipulations; providing nutritional supplements that can overcome deficiencies, such as those often encountered with pregnancies in aged ruminants; or removing social stressors by either separating territorial rivals or uniting colony members). At the same time, assisted reproductive technology should also be viewed as a supplemental strategy that will inevitably become (based on the growing problems with governmental regulatory restrictions to control infectious disease outbreaks), one of the most important tools available for maintaining genetic diversity for populations ex situ as well as in situ.

Acknowledgments

The authors would like to express their appreciation to the members of the AZA Reproductive Sciences Advisory Group and the IETS CANDES Parent Committee for their participation and valuable contributions to these important programs. The authors would also like to express their appreciation to the International Embryo Transfer Society, XY Inc. (Fort Collins, CO, USA) and Omaha’s Henry Doorly Zoo for sponsoring the joint working group meetings and the International Symposia on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife that provides a unique forum for discussions on reproductive sciences in a diverse array of taxa.

Literature Cited

1.  Critser JK, LK Riley, RS Prather. 2002. Application of nuclear transfer technology to wildlife species. Symposium on Reproduction and Integrated Conservation Science. Zoological Society of London, UK.

2.  Goodrowe K, ed. 2002. Zoo Biology special issue. Proceedings of the 2nd International Symposium on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife. In preparation.

3.  Holt WV, T Abaigar, PF Watson, DE Wildt. 2002. Genetic resource banks for species conservation. Symposium on Reproduction and Integrated Conservation Science. Zoological Society of London, UK.

4.  Krisher R, ed. 2002. Zoo biology special issue. Proceedings of the 2nd International Symposium on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife. In preparation.

5.  Loskutoff NM. 2002. Role of embryo technologies in genetic management and conservation of wildlife. Symposium on Reproduction and Integrated Conservation Science. Zoological Society of London, UK.

6.  Loskutoff NM, C Asa, J Brown, M Patton, W Swanson, B Pukazhenthi, O Byers, R Krisher, K Goodrowe, A Pickard, eds. 2002. Proceedings of the 2nd International Symposium on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife. Sponsored by the Henry Doorly Zoo and XY Inc. (Fort Collins, CO). In preparation.

7.  Loskutoff NM, ed. 2001. Proceedings of the 1st International Symposium on Assisted Reproductive Technology for the Conservation and Genetic Management of Wildlife. Sponsored by the Henry Doorly Zoo and XY Inc. (Fort Collins, CO). 234 pages.

8.  Wildt DE, S Ellis, D Janssen, J Buff. 2002. Toward more effective reproductive science for conservation. Symposium on Reproduction and Integrated Conservation Science. Zoological Society of London, UK.