Summer Scholarship Projects for 2009-10

Research Projects in Comparative Functional Anatomy

1. Biomechanical analysis of marsupial spines

The functional demands on the axial skeleton are many and varied. It is an essential organ of both weight bearing and locomotion, and must provide maximal stability while maintaining crucial mobility, in addition to maintaining the integrity of neural structures.

In this study, you will investigate anatomical, biomechanical and comparative aspects of the axial musculoskeletal system in kangaroos in order to answer some of the following questions:

- How does the musculoskeletal anatomy of the spine of kangaroos reflect the varied demands of weight-bearing and locomotion? 
- Does spinal musculature among different species of kangaroos show patterns of modification that reflect ecological adaptation?
- What skeletal features might be useful in interpreting the ecological adaptation of fossil macropods?    

For more information contact:

Dr Natalie Warburton, Anatomy
Email: N.Warburton@murdoch.edu.au

2. Evolutionary anatomy of marsupials

The bandicoots are a poorly studied group of marsupials that have a number of unique morphological features of the musculoskeletal system. Together with the marsupial moles, they are the only marsupials to develop an ossified patella and they are also the only marsupials to lack a clavicle. The hand is modified for digging and the morphology of the foot skeleton shares convergent features with both kangaroos and ungulates. In this project you will describe and compare aspects of the musculoskeletal system of the local quenda (southern brown bandicoot).

For more information contact:

Dr Natalie Warburton, Anatomy
Email: N.Warburton@murdoch.edu.au

3. Evolutionary adaptations of African rodents

African mole rats (family Bathyergidae) superficially resemble other fossorial mammals, with a short, stocky body, short tail and limbs, and reduced eyes and ears. However, unlike other fossorial mammals which primarily utilise large, clawed hands for digging, mole-rats utilise large incisor teeth as their principle digging tool. The forelimbs are used to varying degrees and the hindlimbs are often used to remove excavated soil from the burrows. It is of interest, then, to compare the musculoskeletal adaptations of these burrowing rodents with other ‘moleform’ mammals. In this project you will describe and compare aspects of the appendicular musculoskeletal system of African mole rats, focusing on the hindlimb.

For more information contact:

Dr Natalie Warburton, Anatomy
Email: N.Warburton@murdoch.edu.au

4. Sniffing out a mate

Mole-rats are subterranean mammals endemic to Africa. They are extraordinary because some species are eusocial, where only one female and 1-3 males in a colony are reproductively active; the non-breeding remainder (which may number hundreds of individuals) provide assistance rearing young. The mechanisms that regulate reproductive activity are rapidly reversed when individuals disperse from their natal colony and meet a non-kin of the opposite sex. This exciting project promises fascinating insight into control of reproductive behaviour in what is arguably the most unique mammalian social organisation.

The structure and function of the mole rat vomeronasal organ is of interest because of its potential role to detect sex pheromones. In this project you will histologically examine and describe the morphology of the vomeronasal organ of adult non-breeding Damaraland mole-rats. This will provide important information for further comparative studies.

Relevant references

Molteno, A. J., Kalló, I., Bennett, N. C., King, J. A., and Coen, C. W. 2004. A neuroanatomical and neuroendocrinological study into the relation between social status and the GnRH system in cooperatively breeding female Damaraland mole-rats Cryptomys damarensis. Reproduction 127: 13-22.
Smith, T. D., Bhatnagar, K. P., Dennis, J. C., Morrison, E. E., and Park, T. J. 2007. Growth-deficient vomeronasal organs in the naked mole-rat (Heterocephalus glaber). Brain Research 1132: 78-83.
Xiao, J., Levitt, J. B., and Buffenstein, R. 2006. A stereotaxic atlas of the brain of the naked mole-rat (Heterocephalus glaber). Neuroscience 141: 1415-1435.

For more information contact:

Research Project in Feral Species Management

Spread of the Dieback causing Phytophthora cinnamomi by feral pigs

This project will investigate the role of feral pigs in the dissemination of the plant pathogen Phytophthora cinnamomi in the northern jarrah forest.  Feral pigs and P. cinnamomi are both recognised as key threatening processes to Australia’s biodiversity and conservation values.  Feral pigs are currently widespread throughout the northern jarrah forest and may potentially be spreading P. cinnamomi through the transport of infected soil due tot heir wallowing and rooting behaviour.  This project will investigate the presence of P. cinnamomi in soil samples collected from the hooves and bodies of feral pigs.  DNA extraction and PCR analysis will be used to identify the prevalence of P. cinnamomi in collected soil samples and the likelihood of spread by feral pigs.

For further information contact:

Research Project in Developmental Neurobiology

Anatomical correlates of synaptic properties in the developing visual cortex

Information flow through the cerebral cortex underlies many of the higher brain functions that define human experience – thought, reasoning, sensory perception, emotion. Understanding cortical function requires mapping detailed information about the electrical properties of specific synaptic connections onto the cortical ‘wiring diagram’ provided by anatomical studies.  This project involves using fluorescent and/or confocal microscopy to image and reconstruct fluorescently-labelled, synaptically connected nerve cells in slices of rat visual cortex (see image).  Anatomical properties of these neurons will be correlated with the electrical properties of their synaptic connections, which were measured during electrophysiological recordings conducted at the Laboratory of Molecular Biology (Cambridge, UK). Specific questions that could be addressed in this project include:

1. Does the morphology of synaptically connected neurons in visual cortex differ before and after postnatal eye opening?
2. Do the morphological properties of synaptically connected neurons differ between different regions of visual cortex?
3. Are specific morphological features of synaptically connected neurons correlated with the electrical properties of their synaptic connections?

For further information please contact:

Dr Sarah Etherington
Tel: 9360 6708
Email: s.etherington@murdoch.edu.au

Research Project on Assessment of SHBG in an IVF laboratory setting.

Sex Hormone Binding Globulin and estrogen levels in patients undergoing ART

Sex hormone binding globulin (SHBG) is a protein synthesised by the liver to which both estrogen and the androgens bind with different degrees of affinity. Estradiol increases the liver synthesis of SHBG and androgens decrease it thus generating a system known as the ‘Servo’  mechanism.  Increasing levels of estrogen thus enhance the synthesis of SHBG and cause increasing amounts of both estrogen and testosterone to be bound while testosterone decreases the amount of SHBG synthesised and thus decreases the amount of hormone bound to itself. As hormones that are bound to SHBG have no biological action, increasing amounts of estrogen inhibit their own action while testosterone enhances its own action.

In Reproductive Technology large amounts of estrogen are both given to the patient and are being generated by the patient herself. If the SHBG rises to very high levels, increasing amounts of estrogen may have less and less effect upon both the patient as well as her genital tract. This phenomenon may give us spurious results in relation to the levels of estrogen and their effects on the genital tract. A situation could arise where increasing doses of estrogen have less and less effect on the patient and thus we may see poor estrogenisation in the presence of very high levels of estradiol. Indeed, if the SHBG level rises greatly even very large doses of estrogen may even have no effect on the patient.

The object of this study is to examine the relationship between SHBG, estradiol and testosterone in a group of women undergoing various forms of reproductive technology. These hormones will be measured in a number of different patients as outlined below:

• 10 women undergoing IVF
• 10 women undergoing embryo transfer using hormone replacement therapy
• 5 women in early pregnancy i.e. the first trimester
• 5 women undergoing an assessment of their ovulatory cycle i.e normal women.
• 5 women taking the low dose oral contraceptive.

This project will give the student an opportunity to begin to understand reproductive technology, to use the auto-analyser and to learn about the endocrinology of ovulation and of early pregnancy. Each patient should generate at least 4 levels of each of these  hormones. I think that this will give us some interesting results and should give the students an interesting project to write up. If the results are as interesting as I hope they will be, it is possible that this study will even generate a small publication. However, prior to this study, I will need to pass this through our Institutional Ethics Committee at Curtin University. An early response to this proposal would therefore be appreciated.    

For further information please contact::

Dr Jim Cummins
Tel: 9360 2668
Email: j.cummins@murdoch.edu.au

Research Projects with the Molecular Epidemiology Group

1. Molecular Detection of Cryptosporidium in Fish

Water is increasingly recognised as an important vehicle for transmission of Cryptosporidium. The oocyst is environmentally stable and resistant to inactivation by chlorine at doses commonly used in drinking water treatment. Cryptosporidium can survive for long periods in both freshwater and saltwater and viable human-infectious oocysts have been recovered from several bivalve species. Little is known about the prevalence, geographical distribution of species of Cryptosporidium infecting fish and what the potential health implications are.

The objective of this study is to analyse fish from selected locations in order to determine (a) the prevalence of Cryptosporidium in these fish using microscopy and PCR and (b) to determine whether human-infectious genotypes of Cryptosporidium are found in fish using PCR and sequencing techniques. This study will therefore provide important information on not only the biology of Cryptosporidium infecting fish as well as the transmission dynamics of Cryptosporidium and will also identify if there are any public health implications.

2. Proteomics analysis of Cryptosporidium life cycle stages using Maldi Imaging

Cryptosporidium has a world-wide geographic distribution, can remain viable under cool, moist conditions for many months, and is resistant to conventional disinfectants used by the water industry to disinfect water, including chlorine. It has been responsible for numerous water-borne outbreaks of disease and represents the major public health concern of water utilities in developed nations.
Recent developments in in vitro cultivation have revealed that Cryptosporidium can complete its life cycle in media devoid of host cells, contradicting the current viewpoint that it can only grow on host cells. As the oocyst is believed to be the only stage in the life cycle capable of surviving in the environment, current detection methods for Cryptosporidium within the water industry and studies conducted to assess the survival of Cryptosporidium under environmental conditions have focused on the oocyst. Preliminary work in our laboratory demonstrated the presence of Cryptosporidium life cycle stages appearing in samples, which had been stored in water for long periods of time.  Nothing is known about what proteins are expressed in different life-cycle stages and which proteins could be used as biomarkers to identify, concentrate and analyse different life-cycle stages. The aim of this study is to apply Maldi-imaging mass spectrometry to identify and characterise proteins, which are expressed in life cycle stages.  The data generated from this project will be used to generate biomarkers for life-cycle stages.

3. Examination of the efficiency of Phylomer peptides and Chinese herbs in the control of human and animal infectious diseases.

Cryptosporidium is an enteric parasite, which has a global impact on the health, survival and economic development of >10 million people and animals worldwide, for which no effective chemotherapy is available. Clinical manifestations of cryptosporidiosis vary with age and immunological status. Immunocompetent individuals may have voluminous but self-limiting diarrhoea, however, in immunodeficient individuals; cryptosporidiosis can be associated with chronic, diarrhoea with a fatality rate as high a 60%.

We have identified a series of phylomers (naturally constrained peptide subdomains) in collaboration with a Perth-based biotechnology company called Phylogica), which inhibit the growth of Cryptosporidium by targeting purine salvage enzymes in the parasite. It has been shown that Phylomers can be successfully delivered across the cell membrane using protein transduction domains. Preliminary evidence suggests that phylomers have broad-spectrum anti-microbial activity.

This project is a collaboration with Professor Songhua Hu at Zhejiang University in China. Professor Songhua Hu has successfully used Chinese herbs in treating animal diseases such as bovine mastitis. The study will involve testing Chinese herbs and Phylomers on Cryptosporidium and a range of other pathogens. Techniques learned will include cell culture, drug testing, qPCR and spectrophotometry.

4. Biological Characterisation of a new species of Cryptosporidium in pigs

Ever want to be involved in the naming of a new species? A new species of Cryptosporidium has recently been detected in pigs, which is genetically very distinct.  In order for this species to be formally described in the literature, more information on its biological characteristics is required. This project aims to characterise both the biological characteristics of this species and to further characterise its molecular characteristics. It is anticipated that the results of this project will contribute greatly to our understanding of cryptosporidiosis in pigs and will also result of the formal naming of this species in the scientific literature.

5. Can Australian marsupials transmit Giardia to humans?

Giardia is a protozoan parasite and one of the most common causes of diarrhoea in humans and animals. In Australia, marsupials are one of the dominant mammalian groups within watersheds. It is therefore important to investigate the occurrence of Giardia in marsupials to determine whether infections pose a potential threat to public health, so that appropriate catchment management strategies may be implemented. Little is known of the prevalence and genotypes of Giardia infecting marsupials, although preliminary research suggests that they can be infected with human-infectious species. The objective of this study is to screen marsupial fecal samples using molecular tools from areas of high and low human interaction in order to determine (a) the prevalence of Giardia in marsupials by PCR and (b) to determine whether human-infectious genotypes of Giardia are found in marsupials using PCR and sequencing techniques. This study will therefore provide important information on not only the biology of Giardia infecting marsupials as well as the transmission dynamics of Giardia and will also identify if there are any public health implications.

For more information on the above projects contact:

A/Prof. Una Ryan                                             
Vet Biology Room 3.55
Tel: 9360 2482                                                     
Email: Una.Ryan@Murdoch.edu.au

Research Projects in Small Animal Clinical Immunology

1. Measurement of faecal cytokines in healthy dogs.

Cytokines are mediators that are often produced in inflammatory conditions that occur in the gut, and have both pro and anti-inflammatory characteristics. Work is beginning to be done in investigating the production of cytokines by the gut during disease such as inflammatory bowel disease. Quantification of gut cytokines has in the past relied measurement on intestinal biopsies. A methodology has been described in people to measure these cytokines in faeces, and using them as a marker for clinical response. It is planned to collect faeces from up to ten (10) healthy dogs. The faeces will be screened for faecal pathogens and then processed them with anti-protease preparations before measurement using enzyme immunoassay of selected cytokines (Interleukins -6, -8, -10 and TNF-α). This will form the basis for further evaluation in diseased dogs. The student will learn laboratory based skills and methodology for measurement of cytokines as well as diagnostic laboratory skills for faecal analysis.

2. Further investigation of cytokine mediators in eosinophilic disease.

A study into increased tendency for eosinophilic-related diseases in dogs has identified a potential difference in production of 2 particular cytokines in Rottweilers with eosinophilic disease compared to those without. Stored serum samples have been collected from a variety of dogs, and need to be processed and measurement of these cytokines performed. The student will learn laboratory based skills and then apply then to statistical analysis to determine any significant difference between disease groups of animals.

For more information on these projects contact:

Research Project in Neuroscience

Characterising Pain and Inflammatory Markers in Rheumatoid Arthritis

The sensation of pain is a basic and vital mechanism for the protection of an organism from further harm, leading to avoidance of painful and damaging stimuli, and the protection of injured tissue until recovery occurs and pain ceases. However, the nervous system can become sensitized, leading to non-painful stimuli producing pain. When this occurs, as in arthritis, pain is no longer protective and can be disabling.
Rheumatoid arthritis (RA) is a chronic autoimmune disease characterised by inflammation and destruction of the synovial joints. RA affects around 1% of the population, and around 90% of RA sufferers will become clinically disabled within 20 years of diagnosis. Patients present with pain (predominantly use-related), stiffness, mechanical joint failure, and reduced joint function. Despite progress in disease modifying treatment, most notably by blocking TNF, pain control in RA is still a major challenge.

In order to develop better analgesics, it is vital to understand the mechanisms of sensitization and the development of pain. This has historically been studied using animal models of acute inflammation, but little has been investigated in chronic models of autoimmune diseases which better reflect RA. We have used a chronic animal model, collagen induced arthritis (CIA) in the mouse to study pain behaviours. This project will investigate the changes in pain markers and cell-types in the nervous tissue of mice with CIA by immunohistochemistry. This will help to increase our understanding of sensitization of the nervous system during rheumatoid arthritis, and also may point to potential targets for analgesic development.

For more information on this project contact: