Caracterización cinemática de espermatozoides de mamíferos silvestres criopreservados en el banco criogénico de la Universidad de Cuenca

Abstract

Sperm cryopreservation allows the genetic material of endangered wild species to be preserved and used in assisted reproductive techniques (ARTs). In this sense, this research characterized the kinematics of fresh and cryopreserved spermatozoa from white-tailed deer (Odocoileus virginianus), chorongo monkey (Lagothrix poeppigii), and Amazonian tapir (Tapirus terrestris) available in the cryogenic bank of the University of Cuenca. The frozen (n=12) and vitrified (n=4) samples of each species were thawed and heated, respectively, and assessed in the CASA system (SCA-Evolution® 2018). Furthermore, only post-thaw deer samples were selected by BoviPure® density gradient centrifugation. Deer spermatozoa were more cryo-resistant to the freezing process than the vitrification process, without decreasing (P>0.05) its total motility (MT) after thawing. After sperm selection, however, post-thaw velocities (curvilinear, average, and straight) increased significantly (P>0.05). Vitrification, on the contrary, provoked a reduction (P<0.05) of motilities (total and progressive) and velocities of both deer and monkey spermatozoa. Finally, only fresh asthenospermia samples (> 10% MT) of tapir were reported, since they did not meet the minimum cryopreservation conditions. In conclusion, this first report in Ecuador describes the kinematic characteristics of fresh and cryopreserved spermatozoa from white-tailed deer, chorongo monkeys, and Amazonian tapir. Freezing and vitrification can be used to cryopreserve sperm from these species for use in ARTs. Sperm selection can be a valuable tool to improve the kinematics of cryopreserved sperm.