Reproductive biotechnologies for endangered mammalian species

Abstract

-Assisted reproductive techniques (gamete cryopreservation, artificial insemination, embryo transfer, and in vitro fertilization) allow to propagate small fragmented populations of wild endangered species or domestic breeds. There are the best way for producing several offspring from selected genitors in order to avoid inbreeding depression. However, few mammalian species have been well studied for their reproductive biology whereas huge differences have been observed between these species. Furthermore, materials, methods and experimental designs have to be adapted for each case and each limiting factor (wildness, poor quantity of biological material, disparate locations). Genome resource banking is currently arising and the most applied reproductive biotechnology remains artificial insemination. Assisted reproductive techniques currently developed in domestic species (intracytoplasmic sperm injection, nuclear transfer) may offer new opportunities for the propagation of endangered species. endangered species / artificial insemination / cryopreservation / in vitro fertilization / embryo Résumé -Biotechnologies de la reproduction appliquées aux mammifères en voie de disparition. Les techniques de reproduction assistée (cryoconservation des gamètes, insémination artificielle, transfert embryonnaire, fécondation in vitro) permettent d'accroître des populations, parfois dispersées géographiquement, d'espèces sauvages ou domestiques en voie de disparition. Ces méthodes sont le meilleur moyen pour produire plusieurs descendants à partir de géniteurs sélectionnés de façon à éviter la consanguinité. La biologie de la reproduction est connue pour peu d'espèces de mammifères alors que de grandes différences ont pourtant été mises en évidence entre ces espèces. En outre, les matériels, les méthodes, ainsi que les schémas expérimentaux doivent être adaptés à chaque cas et pour chaque facteur limitant (animaux sauvages, peu de matériel biologique, populations dispersées). Des banques génétiques sont actuellement en voie de constitution mais la technique la plus utilisée reste l'insémination artificielle. Cependant, des biotechnologies de la reproduction en cours de mise au point chez les animaux domestiques (injection intra-cytoplasmique de spermatozoïde, transfert nucléaire) pourraient offrir de nouvelles possibilités pour l'accroissement de populations menacées. espèces menacées / insémination artificielle / congélation / fécondation in vitro / embryon Reprod. Nutr. Dev. 40 (2000)

Estrus cycle monitoring of captive collared peccaries (Pecari tajacu) in semiarid conditions

“…By this moment, the use of transrectal ultrasonography in collared peccaries was not reported, maybe due to the limitations related to the size of the individuals, and due to the need of repetitive anesthesia for sequential examinations. The main limitations of repeatable ultrasound examinations in non-domestic animals are the poor availability of biological material (Comizolli et al 2000) and the risk of physical or chemical restraint . In the present research, we had to use a reduced number of animals due to ethical recommendations, since that the procedure of repetitive restraint is very stressful and sometimes harmful for the individuals.…”

Fertility Cryopreservation

“…Semen banks are currently more developed for rare domestic breeds (cattle, sheep, goats and pigs) than for non-domestic species, but the concept of using them to facilitate the management and conservation of endangered species is being promoted extensively (Roth et al, 1997). In order to maximize genetic diversity, a rare animal from the family bovidae could be saved with 1000 sperm doses collected from 25 different males (Comizzoli et al, 2000).…”

Abandoned Mines Used as Roosts for Reproduction by Townsend’s Big-Eared Bats (Corynorhinus townsendii) in a Protected Area in the Central Highlands of Mexico

“…Shelter and food are considered two limiting factors in the biology of bat populations [3], so any place that provides these two key elements may well be (Corynorhinus townsendii) in a Protected Area in the Central Highlands of Mexico adequate for reproduction, since sufficient food is available to ensure the energy supplies necessary to carry out basic reproductive processes. For these reasons, such sites must be considered as of high priority for the conservation of this group of mammals [4][5][6].…”