Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Marsupials that model melanoma

SCIENTIFIC NAME Monodelphis domestica

TAXONOMY PHYLUM: Chordata CLASS: Mammalia ORDER: Didelphimorphia FAMILY: Didelphidae

Physical description

Credit: Kim Caesar/Nature Publishing Group

The gray short-tailed opossum (Monodelphis domestica) is a small marsupial native to South America. It inhabits forests, dry scrubland and agricultural environments in the eastern central part of the continent, south of the Amazon River. In the wild, individuals typically grow to 12–18 cm in length and weigh 80–100 g, but those kept in captivity may become much larger. As suggested by the common name, their tails are proportionately shorter than in some opossums, measuring about half the length of the body, and most of their fur is grayish brown.

Opossums have well-developed, curved claws and sharp teeth. They are omnivorous, hunting invertebrates, amphibians and reptiles as well as eating fruit and scavenging dead animals. A nocturnal species, opossums are most active during the first few hours after dusk. Opossums are typically solitary.


Opossums can breed throughout the year and produce as many as six litters, each consisting of 6–13 pups. The gestation period is about 14 days, and the pups are not fully developed when born, as with other marsupials. Unlike other marsupials, however, M. domestica females do not have pouches. Instead, the offspring, which are only about 1 cm in length and 0.1 g in weight, attach themselves directly to the female's teats for several weeks.

Research résumé

Several characteristics of the gray short-tailed opossum make it an amenable research model. It is small and docile; can be maintained and bred relatively easily in laboratory settings1,2; and produces large litters of neonates that are readily accessible, owing to the absence of a pouch in the female. M. domestica can be considered a 'prototype' species for basic research on marsupial biology, much the same as Mus musculus, the laboratory mouse, is a prototype for basic research on the biology of placental mammals3. In part because of this status, M. domestica was the first marsupial to have its genome sequenced4.

Because the neonatal immune system is not fully developed, as in other marsupials, M. domestica pups are useful models for transplantation studies and cancer research5,6. M. domestica is the only mammal, other than humans, that is susceptible to melanoma in response to ultraviolet radiation alone3.

M. domestica is also used as a model for diet-induced hypercholesterolemia and hyperlipidemia3,7. There is extensive variation in response to dietary fat and cholesterol among individual opossums, which seems to be largely attributable to a single gene7. Clarifying the role of this gene may lead to a better understanding of dietary lipoprotein physiology in humans. Furthermore, the opossum's omnivorous diet more closely resembles a typical human diet and may therefore make M. domestica a better model than conventional laboratory animals for research on physiological effects of dietary fat and cholesterol3.

Finally, newborn opossum pups have a unusual ability to recover from severe spinal cord injuries and have been used to study regeneration of the nervous system8,9.


  1. 1

    Allison, S.O., Criley, J.M., Kim, J.Y. & Goodly, L.J. Cage change intervals for opossums (Monodelphis domestica) in individually ventilated cages. J. Am. Assoc. Lab. Anim. Sci. 50, 647–652 (2011).

    CAS  PubMed  PubMed Central  Google Scholar 

  2. 2

    Rousmaniere, H. Husbandry of Monodelphis domestica in the study of mammalian embryogenesis. Lab Anim. (NY) 39, 219–226 (2010).

    Article  Google Scholar 

  3. 3

    VandeBerg, J.L. & Robinson, E.S. The laboratory opossum (Monodelphis domestica) in laboratory research. ILAR J. 38, 4–12 (1997).

    Article  Google Scholar 

  4. 4

    Mikkelsen, T.S. et al. Genome of the marsupial Monodelphis domestica reveals innovation in non-coding sequences. Nature 447, 167–177 (2007).

    CAS  Article  Google Scholar 

  5. 5

    Wang, Z., Hubbard, G.B., Pathak, S. & VandeBerg, J.L. In vivo opossum xenograft model for cancer research. Cancer Res. 63, 6121–6124 (2003).

    CAS  PubMed  Google Scholar 

  6. 6

    Wang, Z., Hubbard, G.B., Clubb, F.J. & VandeBerg, J.L. The laboratory opossum (Monodelphis domestica) as a natural mammalian model for human cancer research. Int. J. Clin. Exp. Pathol. 2, 286–299 (2009).

    CAS  Google Scholar 

  7. 7

    Kushwaha, R.S., VandeBerg, J.F. & VandeBerg, J.L. Effect of dietary cholesterol with or without saturated fat on plasma lipoprotein cholesterol levels in the laboratory opossum (Monodelphis domestica) model for diet-induced hyperlipidaemia. Br. J. Nutr. 92, 63–70 (2004).

    CAS  Article  Google Scholar 

  8. 8

    Wheaton, B.J., Noor, N.M., Dziegielewska, K.M., Whish, S. & Saunders, N.R. Arrested development of the dorsal column following neonatal spinal cord injury in the opossum, Monodelphis domestica. Cell Tissue Res. doi:10.1007/s00441-014-2067-6 (published online 9 December 2014).

  9. 9

    Saunders, N.R. et al. Age-dependent transcriptome and proteome following transection of neonatal spinal cord of Monodelphis domestica (South American grey short-tailed opossum). PLoS ONE 9, e99080 (2014).

    Article  Google Scholar 

Download references


Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Harrington, M. Marsupials that model melanoma. Lab Anim 44, 53 (2015).

Download citation


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing