The male germ unit of Rhododendron : quantitative cytology, three-dimensional reconstruction, isolation and detection using fluorescent probes

The sperm cells of Rhododendron laetum and R. macgregoriae differentiate within the pollen tube about 24 h after germination in vitro. Threedimensional reconstruction shows that the sperm cells are paired together, and both have extensions that link with the tube nucleus, forming a male germ unit. Quantitative analysis shows that the sperm cells in each pair differ significantly in surface area, but not in cell volume nor in numbers of mitochondria or plastids. When isolated from pollen tubes by osmotic shock, the sperm cells became ellipsoidal and surrounded by their own plasma membrane, while a proportion remained in pairs linked by the inner tube plasma membrane. Both generative and sperm cells are visualized in pollen tube preparations by immunofluorescence with anti-tubulin and anti-actin monoclonal antibodies (MAbs) combined with H33258 fluorescence of the nuclei. Video-image processing shows the presence of an axial microtubule cage in the generative cells, and some microtubules are present in the cytoplasmic extensions that clasp the tube nucleus. Following sperm cell division, the extensive phragmoplast between the sperm nuclei is partitioned by the plasma membranes.

Characterisation and application of a bovine U6 promoter for expression of short hairpin RNAs

Background
The use of small interfering RNA (siRNA) molecules in animals to achieve double-stranded RNA-mediated interference (RNAi) has recently emerged as a powerful method of sequence-specific gene knockdown. As DNA-based expression of short hairpin RNA (shRNA) for RNAi may offer some advantages over chemical and in vitro synthesised siRNA, a number of vectors for expression of shRNA have been developed. These often feature polymerase III (pol. III) promoters of either mouse or human origin.
Results
To develop a shRNA expression vector specifically for bovine RNAi applications, we identified and characterised a novel bovine U6 small nuclear RNA (snRNA) promoter from bovine sequence data. This promoter is the putative bovine homologue of the human U6-8 snRNA promoter, and features a number of functional sequence elements that are characteristic of these types of pol. III promoters. A PCR based cloning strategy was used to incorporate this promoter sequence into plasmid vectors along with shRNA sequences for RNAi. The promoter was then used to express shRNAs, which resulted in the efficient knockdown of an exogenous reporter gene and an endogenous bovine gene.
Conclusion
We have mined data from the bovine genome sequencing project to identify a functional bovine U6 promoter and used the promoter sequence to construct a shRNA expression vector. The use of this native bovine promoter in shRNA expression is an important component of our future development of RNAi therapeutic and transgenic applications in bovine species.

In vitro spheroids and metastatic epithelial ovarian cancer

This thesis investigated the role of cellular aggregation in the spread of epithelial ovarian cancer. Cell aggregation was studied in vitro in order to identify markers of disease progression and cell-cell adhesion. Proteomics was then used to identify additional proteins associated with cell aggregation and survival.

Evaluation of novel dairy fatty acids in inflammatory muscle-wasting conditions

This work examined the effects of a novel dairy fatty acid conjugated linoleic acid (CLA) and its effects on muscle wasting in advanced cancer. Results showed a positive anti-inflammatory role of CLA on the supression of tumour growth and established a model for studying the action of CLA in human muscle-wasting conditions.

Interactions of Plasmodiophora brassicae with Arabidopsis thaliana

The host-pathogen interaction study between Arabidopsis thaliana and Plasmodiophora brassicae was conducted at cellular and molecular level for a better understanding of the pathogen. Gene expression studies conducted therin at the early time points during the infection process of P. brassicae discovered new information on the components of compatibility.

Haematology of cultured Murray cod

Murray cod are Australia's largest freshwater fish: endangered in the wild, but supporting a boutique industry. This project studied the blood cells of Murray cod and those affected by the disfiguring chronic erosive dermatopathy. This has provided insight into the factors affecting Murray cod health.