Laboratory opossums (Monodelphis domestica) are marsupials that are native to South America. Unlike North American opossums, which are the size of a full-grown cat, they’re only about six inches long. But for such a small size, they’ve made quite an impact in the field of biomedical research.
They are excellent research models for a variety of reasons. Mini opossums are the only mammal (besides humans) to develop malignant melanoma after UV radiation. Because of this trait, researchers can test new treatments for melanoma and research prevention strategies. And amazingly, these animals also have the ability to heal after severe spinal cord injuries sustained during the first week of life. Adults are unable to do this, so researchers are working to identify the genes that switch this capability on and off.
They give birth to extremely underdeveloped young (gestation is only 14-15 days!), which cling to the mother and remain attached to her for a few more weeks until they are fully developed. This unique trait makes them an excellent model for research on early development, as well as transplant and cancer research. The laboratory opossum is also the first marsupial to have its genome sequenced, and in addition to the applications above, it’s also important in heart disease research, HIV research, and comparative genetics. They’re pretty important animals- read more about them here!