Embryogenesis in conservation biology — Or, how to make an endangered species embryo

Abstract

Abstract Embryo technologies have not as yet contributed to practical conservation of rare wildlife species. Production of young following artificial insemination (AI), embryo transfer (ET) or in vitro fertilization (IVF) has been sporadic, and it is now clear that biological differences among species limit our abilities to adapt these techniques easily to rare species. Nonetheless, there is encouraging progress at two levels. First, there is more acceptance that rare wildlife species safely tolerate the manipulations necessary to collect basic reproductive information or to test artificial breeding. This has increased access to rare animal populations and helped develop organized captive breeding programs, many of which emphasize the need for more research. Secondly, a gradually developing database about how these species reproduce is driving more systematic experimentation and artificial breeding attempts. Studies in our laboratory focus on producing embryos in vivo or in vitro. When essential information is available on fundamental reproductive processes, and, especially when comparative data are available from a domesticated animal model, then AI techniques are adapted to the endangered species. When few data are available, then studies emphasize using IVF (often in combination with in vitro oocyte maturation) to examine the factors regulating embryo formation and viability. These strategies are illustrated by recent progress involving (i) AI of select species of cervids, felids and mustelids, (ii) oocyte maturation in felids and (iii) IVF and ET in felids. Offspring have been produced, but perhaps more important are the answers to fundamental and mechanistic questions about why some wildlife species thrive and others do not. If reality-based conservation is defined as a continual data-gathering process that assimilates any and all information ultimately useful for preserving species, then embryo technologies are making considerable contributions to conservation biology.