Individually ventilated cage system for laboratory opossum vivarium

PROJECT SUMMARY/ABSTRACT The goal is to establish a state-of-the-art vivarium, which will be dedicated exclusively to the UTRGV Laboratory Opossum (Monodelphis domestica) Research Resource, and which will provide expanded opportunities for biomedical research with this unique laboratory animal to investigators and students at UTRGV and other

institutions. This resource is the only large research colony of any marsupial species, and it contains the only genetic stocks and inbred strains that have been developed for any marsupial species. The resource is widely shared with investigators from other institutions, and it serves as the only readily accessible source of research

animals, breeding nuclei, and biological materials from this species, and of opportunities for investigators from other institutions to conduct hands-on (or remote) research with this species without establishing their own colonies. State funds were secured for construction of the building that will contain the new vivarium, and the

building will be ready for occupancy early in 2024. Use of the funds was restricted to the building and fixed equipment; the funds could not be used for caging. To fill the gap in funding, the single specific aim of this proposal is to purchase and install ten racks of a state-of-the-art IVC system. Sixteen racks currently in

use are available to be moved to the new vivarium. The complete caging system will include 13 Optimice racks (1,300 cages) for individually housed opossums and 13 Optirat racks (546 cages) for mated pairs, mothers with litters, and groups of littermates. Six racks of each type will be installed in each of two breeding/holding rooms;

and one rack of each type will be installed in a smaller room for research with infectious agents or for quarantine purposes. The breeding/holding rooms will house the 20 genetic stocks and inbred strains that comprise the breeding colony, as well as animals used in research that does not involve infectious agents. The current

opossum resource has a steady state of 1,200 animals, which are housed in an overcrowded vivarium with many deficiencies. The new vivarium and caging system will enable the steady state of the colony to increase to 1,726 animals, which will be maintained under optimal conditions for animal welfare and for financial and operational

efficiency. That number of animals will be sufficient in the intermediate-term future for maintaining the 20 breeding groups and providing sufficient animals and research capacity to meet the national need. The IVCs will provide maximal protection from the transmission of infectious diseases, high air quality for the animals, and

minimal exposure of staff to allergens that emanate from the animals. Moreover, the selected caging system is the ultimate in green technology design; it depends on filtered room exhaust air being pulled through the cages and out of the building by the HVAC system, rather than on motors and blowers. The overarching outcome

will be to establish an efficient, high-quality, high-capacity laboratory opossum research resource that is capable of meeting current demand for laboratory opossums for biomedical research, and of fulfilling the increasing institutional and national need for this species well into the future.