The laboratory opossum, Monodelphis domestica, was developed as an animal model in the Department of Genetics at the Southwest Foundation for Biomedical Research. This animal model has become the most commonly used marsupial in biomedical research. The laboratory opossum is used in a broad range of research programs including projects focused on development, physiology and disease susceptibility. Over seventy-nine thousand animals have been produced by the Department of Genetics colony, and animals have been distributed to research programs and breeding colonies throughout the world. Over 400 scientific publications in the last two years have been based on research using the Monodelphis as an animal model.
The current colony consists of 1909 individuals with pedigrees that extend as far back as 39 generations. The 38 founders of the colony came from four different locations in Brazil and a single site in Boliva. Twenty-eight founders are represented in the existing gene pool.
For those unfamiliar with Monodelphis domestica as an animal model, the following publications provide a primer:
Husbandry: VandeBerg JL, Williams-Blangero S. Chapter 19: The Laboratory Opossum. In: The UFAW Handbook on the Care and Management of Laboratory and Other Research Animals, 8th edition. Series: The Universities Federation for Animal Welfare. R Hubrecht and J Kirkwood, eds. Blackwell Publishing, Ames, IA: pp. 246-261, 2010. [Web Book]
Spontaneous disease: Hubbard GB, Mahaney MC, Gleiser CL, Taylor DE, VandeBerg JL. Spontaneous pathology of the gray short-tailed opossum (Monodelphis domestica). Lab Anim Sci 47:19-26, 1997. [Article Abstract]
Monodelphis linkage map: Samollow PB, Gouin N, Miethke P, Mahaney SM, Kenney M, VandeBerg JL, Graves JA, Kammerer CM. A microsatellite-based, physically anchored linkage map for the gray, short-tailed opossum (Monodelphis domestica). Chromosome Res. 2007;15(3):269-81. [Article Abstract]
A complete bibliography of publications arising from the use of this animal model at SFBR may be found here.
Research Projects
Skin and Eye Cancers in Monodelphis
Scientists in the Department of Genetics developed the Monodelphis as a model for skin cancer research. The laboratory opossum is the only animal model that develops melanoma in response to UV exposure alone, just as humans do. Genetic research has demonstrated a substantial genetic component to UV-induced eye cancers in this animal model.
Genetic Influences on Cholesterol
SFBR scientists have shown the laboratory opossum to be a valuable model for dietary-induced hypercholesterolemia, a major contributor to heart disease. Their research has revealed that the primary determinant of resistance to this condition in Monodelphis is a single recessive gene. Further investigations are underway to identify the gene involved and and to determine how it functions.
Spinal Cord Injury Repair
Foundation scientists are investigating the unique capability of Monodelphis to repair severe spinal cord injuries during the first week of life. These investigators are seeking to identify the central nervous system genes that are critical to the capability for spinal cord repair which is found only in young animals. This exciting work may suggest new pathways to explore in the development of effective treatments for humans who suffer from the devastating effects of spinal cord injuries.
Genetics Research
It is anticipated that the laboratory opossum will continue to grow in importance for genetic research as a result of two recent advances. First, the Monodelphis was selected as the first marsupial species to be sequenced at the National Human Genome Research Institute. Second, SFBR, scientists developed a linkage map for Monodelphis which will facilitate future genome scans in this increasingly important model for biomedical research. Together, the Monodelphis genome sequence and gene map will provide powerful tools for future genetic studies in Monodelphis domestica.
