On-site Sperm Cryopreservation for Aquatic Repository Development and User Group Linkage

Abstract

Although on-site cryopreservation of aquatic species sperm in nitrogen-vapor shipping dewars has been used for more than 30 yr, many limitations remain. Due to the size of shipping dewars, most studies are small scale and can only produce tens of samples. The freezing temperatures that can be achieved are also affected by the size of the dewar and the number of samples being frozen due to the heat load. In addition, often due to timing or remote location these samples cannot be shipped, and if they are shipped, quality can be lost and the samples must be discarded. The goal of this thesis was to create a mobile aquatic cryopreservation laboratory that could operate at research and commercial-scale capacities and, could function under multiple scenarios in different on-site environments with a high level of quality control. There were three operational designs identified for the mobile laboratory: 1) self-contained work inside the unit using generator power; 2) work inside the unit using external facilities power; 3) using the equipment inside a host facility. Computer-aided design software was used to model a 3.8 m long trailer and various internal components to evaluate different configurations. From the final design, the layout inside the mobile laboratory was constructed and initially tested at the LSUAC Aquatic Germplasm and Genetic Resource Center. This demonstrated that the portable generator provided sufficient power for simultaneous use of all equipment. The capitol and variable costs were documented of construction and integration of the mobile laboratory into an existing cryopreservation facility at different levels of automation. This led to blueprints and layout information that can provide guidance for others to build their own units. Finally, the mobile laboratory was deployed into the field to cryopreserve sperm from Blue Catfish, Xiphophorus spp., and Red Snapper. This resulted in processing of 684 males and 6,838 French straw being produced. This work provides a general approach for high-throughput on-site cryopreservation of aquatic species for repository development and user group linkage. Germplasm repositories would allow the reconstitution of species or populations, and linking users could help remove standardization and quality control bottlenecks.