A MHC class I gene in the Australian brushtail possum (Trichosurus vulpecula)

The Australian native brushtail possum (Trichosurus vulpecula) is a major agricultural and environmental pest in New Zealand. Brushtail possums were first introduced to New Zealand in the 1800s to establish a fur trade (Clout and Ericksen 2000). Due to a lack of predators and an excellent ability to adapt to a variety of habitats, their numbers have increased to approximately 70 million resulting in extensive environmental and economic damage to New Zealand (Montague 2000). Brushtail possums are also a maintenance host of bovine tuberculosis (Tb). Due to their close proximity to farmed cattle and deer, possums spread Tb to these animals that are of great economic importance (Coleman and Caley 2000). Various methods are being developed to control numbers, one of which is immunocontraceptive vaccines (Cowan 2000). The underlying concept of immunocontraception is to use virus or bacteria to deliver recombinant antigens, which elicit immune responses against aspects of fertilization and/or fetal development.