This thesis describes a comprehensive study of the cellular responses of a number of endangered marsupial species with a principal focus on the tammar wallaby (Macropus eugenii) as a model macropod species. The development of in vitro experimental assays for the assessment of immune responses in this model species are described, which provided a set of benchmarks for comparisons with other members of the Macropodidae and with eutherian mammals. Once this data was collected and protocols were established, the study was extended to include investigations of the immune responses in opportunistic samples obtained from the Rufous Hare-wallaby (Lagorchestes hirsutus), the Long-footed potoroo ( Potorous longipes) and the more common, but nonetheless still vulnerable, Long-nosed potoroo (Potorous tridactylus) with a view to investigating their apparent susceptibility to infection with intracellular pathogens, particularly mycobacterial species. The findings from the application of these assays suggest that the cellular immune responses of these species are relatively complex and involve a level of sophistication that rivals their eutherian counterparts. Specifically peripheral blood and tissue leukocytes were morphologically similar to those of other mammals, with the exception of tammar wallaby monocytes that appeared to contain few lysosomal granules, and the basophils of the Rufous Hare-wallaby that contained very large atypical granules. The overall findings of this study suggest that the immune systems of macropod species possess most of the sophistication associated with that of eutherian mammals. Whilst some differences were apparent in cells and their products in the test species, no single factor common to all macropods was identified as a cause for immune dysfunction. It appears likely that as yet undefined factors related to their confinement rather than an inherent defect in their immunocapacity is responsible for the apparent disease susceptibility of these animals. / Doctor of Philosophy (PhD)
| Identifer | oai:union.ndltd.org:ADTP/181754 |
| Date | January 2002 |
| Creators | Young, Lauren Jill, University of Western Sydney, College of Science, Technology and Environment, School of Science, Food and Horticulture |
| Source Sets | Australiasian Digital Theses Program |
| Language | English |
| Detected Language | English |
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