Epigenetic and biomarker approaches to improving dairy cow fertility. The dairy industry will not deliver sustainable higher productivity unless the reproductive performance of dairy cows is significantly improved. This expected outcome will be achieved via the identification of epigenetic and protein biomarkers of improved fertility that will be used to develop superior breeding stock. Caruncular and intercaruncular tissues and blood have been obtained from both fertile (New Zealand Holstein-Fr ....Epigenetic and biomarker approaches to improving dairy cow fertility. The dairy industry will not deliver sustainable higher productivity unless the reproductive performance of dairy cows is significantly improved. This expected outcome will be achieved via the identification of epigenetic and protein biomarkers of improved fertility that will be used to develop superior breeding stock. Caruncular and intercaruncular tissues and blood have been obtained from both fertile (New Zealand Holstein-Friesian) and sub-fertile (North American Holstein-Friesian) cows within pasture-based dairying systems that include seasonal calving and subclinical uterine inflammation (associated with poor reproductive performance). Determinations will be conducted using deep parallel (next generation) sequencing and mass spectrometry.Read moreRead less
Interactions between cells and extracellular matrix in the epithelial-mesenchymal transition of the ovarian follicular stratified epithelium. The lining of many mammalian organs and cavities contain cells that can transform into different cells to bring about organ development or repair but if it goes horribly wrong the cells become metastatic cancers. This project examines the key features of this process especially the roles of matrix that develops around the cells in this process.
Subcellular co-localisation of interacting proteins that control maturation in mammalian eggs. The final maturation of mammalian eggs (oocytes) before fertilisation involves a cascade of interactions between protein kinases and phosphatases, the shuttling of these proteins between cytoplasm and nucleus, and microtubule assembly and disassembly. In this project we have proposed that interacting proteins involved in oocyte maturation are co-localised at subcellular sites in oocytes, in a strict t ....Subcellular co-localisation of interacting proteins that control maturation in mammalian eggs. The final maturation of mammalian eggs (oocytes) before fertilisation involves a cascade of interactions between protein kinases and phosphatases, the shuttling of these proteins between cytoplasm and nucleus, and microtubule assembly and disassembly. In this project we have proposed that interacting proteins involved in oocyte maturation are co-localised at subcellular sites in oocytes, in a strict temporal and spatial manner. The co-localisation of proteins in oocytes is considered a fundamental mechanism that ensures coordination of time-bound cellular events and proper preparation of oocytes for fertilisation and early embryo development. There are important implications for IVF and cloning by nuclear transfer.Read moreRead less
Stimulation of the mammalian reproductive system by olfactory pathways. This project answers fundamental questions about mammalian reproductive biology but, because we work with the sheep model, our findings can be applied to two of Australia's biggest export industries, wool and sheepmeat. Understanding the reproductive responses of our production animals to exteroceptive factors such as socio-sexual signals, photoperiod and nutrition is an important first step towards refining the management ....Stimulation of the mammalian reproductive system by olfactory pathways. This project answers fundamental questions about mammalian reproductive biology but, because we work with the sheep model, our findings can be applied to two of Australia's biggest export industries, wool and sheepmeat. Understanding the reproductive responses of our production animals to exteroceptive factors such as socio-sexual signals, photoperiod and nutrition is an important first step towards refining the management of breeding programs. It has been argued that this approach will also minimise, and perhaps even remove the need for, exogenous hormones and drugs for controlling the reproductive process.Read moreRead less
Male to female sperm signalling – a new role for sperm in reproduction? Male seminal fluid is commonly thought simply to provide sperm for conception. This project aims to investigate a lesser known action of sperm: modifying the female immune response to increase the chances of reproductive success. The project aims to define the molecular pathway through which sperm interact with female cells, particularly how B-defensins on sperm bind to Toll-like receptors to stimulate female immune toleranc ....Male to female sperm signalling – a new role for sperm in reproduction? Male seminal fluid is commonly thought simply to provide sperm for conception. This project aims to investigate a lesser known action of sperm: modifying the female immune response to increase the chances of reproductive success. The project aims to define the molecular pathway through which sperm interact with female cells, particularly how B-defensins on sperm bind to Toll-like receptors to stimulate female immune tolerance. The project plans to use embryo transfer and genetic mouse models to determine the physiological benefit of sperm signalling. Evidence that seminal fluid signalling operates in mammals to ensure optimal female reproductive investment would advance knowledge of the male contribution to the reproductive process.Read moreRead less
Mechanisms of manchette function. This project aims to define the function of the manchette, a poorly understood microtubule-based structure present in haploid male germ cells. This project aims to define key mechanisms underpinning manchette development and movement, and to generate a detailed picture of the dynamics of germ cell development using imaging technologies and unique animal models. Such knowledge should improve the understanding of how male fertility is achieved, the origin of infer ....Mechanisms of manchette function. This project aims to define the function of the manchette, a poorly understood microtubule-based structure present in haploid male germ cells. This project aims to define key mechanisms underpinning manchette development and movement, and to generate a detailed picture of the dynamics of germ cell development using imaging technologies and unique animal models. Such knowledge should improve the understanding of how male fertility is achieved, the origin of infertility and how species-specific differences in sperm form are achieved. Such insights may ultimately lead to improved agricultural efficiencies and job creation.Read moreRead less
The molecular basis of sperm competition. This project aims to unravel the molecular basis of reproductive conflicts. Males compete for paternity and this continues after mating if females copulate and receive semen from multiple males. In ants and bees, molecules in males’ ejaculates recognise and kill rival males’ sperm. Reproductive proteins in leaf cutter ants’ seminal fluid may be the molecular agents of sperm competition. This project will investigate reproductive proteins and their functi ....The molecular basis of sperm competition. This project aims to unravel the molecular basis of reproductive conflicts. Males compete for paternity and this continues after mating if females copulate and receive semen from multiple males. In ants and bees, molecules in males’ ejaculates recognise and kill rival males’ sperm. Reproductive proteins in leaf cutter ants’ seminal fluid may be the molecular agents of sperm competition. This project will investigate reproductive proteins and their functioning and effects on reproductive success. This project will show how reproductive conflicts over paternity operate on the protein level and may lead to novel avenues for future pest control.Read moreRead less
Use of quinone adducted peptides in the regulation of fertility. This project describes a novel strategy for the non-surgical induction of sterility in male and female mammals with applications in the fields of biotechnology, veterinary medicine and the humane control of pest animal species. The approach is dependent upon the known sensitivity of the germ line to oxidative stress. The strategy rests upon the demonstration that quinone-adducted peptides will selectively bind to non-renewable cel ....Use of quinone adducted peptides in the regulation of fertility. This project describes a novel strategy for the non-surgical induction of sterility in male and female mammals with applications in the fields of biotechnology, veterinary medicine and the humane control of pest animal species. The approach is dependent upon the known sensitivity of the germ line to oxidative stress. The strategy rests upon the demonstration that quinone-adducted peptides will selectively bind to non-renewable cell types in the ovary and testis and redox cycle at the cell surface generating a highly localised state of oxidative stress. This stress will then recapitulate the impact of radiation on reproductive tissues by selectively compromising the viability of the germ line, inducing a state of sterility.Read moreRead less
Brain Regulation of Reproduction: Challenging the ‘KNDy’ Hypothesis. The brain switches reproduction on and off by changing the frequency of pulses of gonadotrophin releasing hormone. The processes that produce the pulses have been a puzzle for decades but, recently, brain cells that produce three peptides (kisspeptin, neurokinin B, dynorphin), known as ‘KNDy cells’, have been heralded as the ‘missing link’, or even the ‘pulse generator’. Using sheep, this project will challenge the KNDy hypothe ....Brain Regulation of Reproduction: Challenging the ‘KNDy’ Hypothesis. The brain switches reproduction on and off by changing the frequency of pulses of gonadotrophin releasing hormone. The processes that produce the pulses have been a puzzle for decades but, recently, brain cells that produce three peptides (kisspeptin, neurokinin B, dynorphin), known as ‘KNDy cells’, have been heralded as the ‘missing link’, or even the ‘pulse generator’. Using sheep, this project will challenge the KNDy hypothesis with pheromones and with acute increases in nutrition, two factors that rapidly increase the frequency of gonadotrophin releasing hormone pulses. The outcomes of this research are directly relevant to the optimisation of reproductive management in farm animals, wildlife and humans.Read moreRead less
Evolutionary proteomics of social insects. This project aims to understand the molecular mechanisms that affect fertility in honeybees and leaf-cutting ants by identifying the function of proteins in male and female secretions related to insemination and sperm storage. The understanding of these general principles will have important applications for honeybee breeding.