Trehalose, Glycerol and Dimethyl Sulfoxide Supplementation for Cryopreservation Media of Honey Bee Drone Semen

Abstract

The cryogenic storage of honey bee drone (Apis mellifera) semen is a rapidly developing practice, driven by the need to preserve bee colonies and the decline in gamete quality following cryopreservation. Advances in cryobiology, coupled with procedural refinements and the development of new methods for cryopreservation of male gametes at different temperatures, provide promising results for improving drone semen preservation. Innovative strategies involve the incorporation of additives within preservation media to enhance important spermatozoa parameters. Our study aimed to assess the effectiveness of cryoprotectants (CPAs), namely trehalose, glycerol, and dimethyl sulfoxide (DMSO), on the motion characteristics of honey bee drone sperm cells during cryopreservation and subsequent thawing. Using Sperm Class Analyzer (SCA) and Computer-Assisted Sperm Analysis (CASA), we evaluated the impact of these supplements on sperm motility and kinetic parameters. Our findings indicated significant differences in sperm motility (non-progressiveness and progressiveness) and kinetics (curvilinear velocity and linearity) across treatments with trehalose, DMSO, and glycerol. Trehalose supplementation retained significantly higher percentages of sperm motility and kinetic parameters post-cryopreservation compared to DMSO and glycerol. Nevertheless, despite the utilization of new protocols, media, and supplementation, the results obtained are often unsatisfactory. The research provides valuable information for enhancing the efficacy of cryopreservation media to optimize the successful outcome of honey bee drone spermatozoa storage.