Effects Of Leptin On Follicle Growth And Ovulation
Funder
National Health and Medical Research Council
Funding Amount
$196,470.00
Summary
Leptin is a recently discovered hormone which is very important in controlling body weight. Extremely obese, or extremely underweight women, find it difficult to become pregnant, and leptin is probably the connection between weight and fertility. This may be a particularly important factor in polycystic ovary syndrome (PCOS), a distressing condition which affects 5% of women and causes both obesity and infertility. Exciting new research suggests that leptin also affects the immune system, and pr ....Leptin is a recently discovered hormone which is very important in controlling body weight. Extremely obese, or extremely underweight women, find it difficult to become pregnant, and leptin is probably the connection between weight and fertility. This may be a particularly important factor in polycystic ovary syndrome (PCOS), a distressing condition which affects 5% of women and causes both obesity and infertility. Exciting new research suggests that leptin also affects the immune system, and previous NH and MRC funding has enabled us to demonstrate that the immune system plays a crucial role in maintaining normal ovarian function. The nutritional status of the body, the immune system and the reproductive system all interact, and leptin appears to be the connecting link between these three major systems. We propose that leptin plays a major role in the ovary, and wish to determine how leptin mediates the effects of bodyweight and the immune system on ovarian function. Laboratory rats will be treated with leptin, their food intake and weight recorded, and a few weeks later the rats will have their ovaries removed. We will find out whether ovaries respond to leptin, or whether the ovarian response changes according to the menstrual cycle: perhaps leptin is very important just before ovulation, but it does not affect menstruation? Do any ovarian cells make leptin? Will leptin stimulate ovaries to produce more oestrogen or progesterone, or ovulate more eggs? We will also identify immune system cells in the ovary, and note whether leptin affects them. We will be able to relate all this data to weight and diet. Increased understanding of leptins' effect on the ovary has the potential to lead to new, improved treatments for PCOS or for unexplained cases of infertility. It is also possible that in the future a weight-loss regime might be developed which takes a womans monthly cycle into account, therefore making weight-loss more efficient and attainable.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
Objectives: 1. Learn techniques of spawning induction. Raise scallops under lab conditions with emphasis on growth & survival under different temperature & feeding regimes. 2. Provide details for identification of the series of planktonic larval stages for future larval field ecological studies
SCRC: Tackling Microbial Related Issues In Cultured Shellfish Via Integrated Molecular And Water Chemistry Approaches
Funder
Fisheries Research and Development Corporation
Summary
Over the last few years, the shellfish industry has experienced an increase in unpredictable hatchery and settlement rates of abalone and oyster larvae – batches crash for no apparent reason despite successful spawning and fertilisation. Additionally, farms experience unexplained stock losses during grow-out periods in both land and sea based culture facilities. Recently, the Australian abalone aquaculture industry ranked the ‘investigation into the causes of summer mortality and development of ....Over the last few years, the shellfish industry has experienced an increase in unpredictable hatchery and settlement rates of abalone and oyster larvae – batches crash for no apparent reason despite successful spawning and fertilisation. Additionally, farms experience unexplained stock losses during grow-out periods in both land and sea based culture facilities. Recently, the Australian abalone aquaculture industry ranked the ‘investigation into the causes of summer mortality and development of management protocols to minimize or prevent losses’ as one of the top three priorities for the industry (J. Fromm, pers.comm.). In oysters, farmers are looking for indicators of potential culture problems (i.e. hatchery failures) (M. Bermudes, pers.comm.).
Our ability to manage such events would be strengthened if we could determine and subsequently monitor the causative agent. There is evidence from the international literature to suggest that the cause of these events may be microbial in nature and, anecdotally, farmers believe the mortality of shellfish experienced across seasons may be a product of hydrochemistry interactions with bacteria.
Recently, CSIRO developed and adapted a suite of new cost-effective molecular tools that enable complex microbial communities in water, sediment or soil samples to be rapidly described without the need for physical culturing of the microorganisms. The identification of both commensal and harmful microorganisms which are responsive to changes in abiotic environmental parameters, as well as low abundant microbes that represent a reservoir for infection, can now be undertaken using highly sensitive and high throughput genomics techniques. Furthermore, we have developed multivariate statistical approaches capable of describing links between microbial community profiles and causative factors. We are confident that this burgeoning area of research, metagenomics, will have direct uptake and application in a wide range of aquaculture industries (including food protection and human health aspects) particularly given the increasingly cost-effectiveness of next generation sequencing.Read moreRead less
An Investigation Of Factors Which Structure Recruitment To The West Coast Prawn Fishery And Development Strategies For Stock Rehabilitation And Enhancement
Funder
Fisheries Research and Development Corporation
Summary
Objectives: 1. An investigation of factors which structure recruitment to the West Coast prawn fishery and development strategies for stock rehabilitation and enhancement TRUST ACCOUNT
Genetic (microsatellite) Determination Of Stock Structure Of The Blue Swimmer Crab In Australia
Funder
Fisheries Research and Development Corporation
Funding Amount
$75,015.00
Summary
Apart from the work by Bryars & Adams (1997) on three assemblages of Potunus pelagicus in South Australia, there have been no studies aimed at determining the extent to which blue swimmer crabs are represented by different stocks in spatially-isolated habitats within a given geographical region in Australia. Furthermore, the studies in South Australia were carried out using allozymic analyses, which typically do not have the same ability to discriminate precisely between the boundaries of stock ....Apart from the work by Bryars & Adams (1997) on three assemblages of Potunus pelagicus in South Australia, there have been no studies aimed at determining the extent to which blue swimmer crabs are represented by different stocks in spatially-isolated habitats within a given geographical region in Australia. Furthermore, the studies in South Australia were carried out using allozymic analyses, which typically do not have the same ability to discriminate precisely between the boundaries of stocks, as can be achieved with the microsatellite techniques we intend to use in our proposed study (see Wright & Bentzen, 1995; OConnell & Wright, 1997). As with all fisheries, a basic prerequisite for managing the fishery for blue swimmer crab is the identification of production units or stocks of a species since inadequate knowledge of stock structure may lead to over- or under-exploitation (Smith et al., 1997). For the following specific reasons, information as to whether there are one or more stocks of swimmer crabs, ie. genetically discrete assemblages, in a given region is crucial for managing the fishery for this portunid. 1. The ability of managers to respond appropriately to any marked decline in the abundance of blue swimmer crabs within part of the range of this species will depend on knowledge of whether or not the crabs in that region constitute a single stock or are part of a larger and more widely-distributed stock. In this context, it is highly relevant that the work of Bryars & Adams (1997) showed that, in spite of the high vagility of blue swimmer crabs, the assemblages of this species in relatively nearby localities can be genetically different and thus constitute different stocks. It should also be recognised that, as the fishery for blue swimmer crabs increases, the mortality produced by repeated captures and releases of undersized crabs could place pressure on those stocks that are being heavily fished. 2. There is a need to identify the different stocks of blue swimmer crabs that exist within a region in order to facilitate adaptive management (and opportunities for research) of separate populations that are exposed to (or experience) different levels of fishing mortality. 3. Any modelling of the blue swimmer crab fishery in a region is dependent on knowing whether the assemblages in that region constitute one or more stocks. 4. Fisheries managers need to know the extent to which the biological characteristics such as growth rates and fecundity, vary amongst stocks. This can be explored in Western Australia because biological data are continuing to be accumulated for different assemblages of blue swimmer crabs in this state under the auspices of past and current FRDC grants (FRDC Project Nos 95/042 and 97/137). As well as responding to the immediate need for stock identification of blue swimmer crabs, the proposed project will generate detailed information on the population genetic structure of Portunus pelagicus over virtually its entire range in Australia. The resultant information will help to identify the importance of various factors, such as climate, current flow and physical isolation, in determining the stock structure of this species. In turn, this information will be useful should genetic management of this species become a priority, e.g. for conserving genetic diversity within stocks and for identifying stocks possessing desired performance traits.
Literature Cited
Bryars, S. & Adams, M. (1997) Population structure of the blue swimmer crab, Portunus pelagicus, in South Australia. In: Kumar, M. S. (ed.) Proceedings of the First National Workshop on Blue Swimmer Crab Portunus pelagicus. SARDI Reseach Report, Series Number 16, SA. OConnell, M. & Wright, J. M. (1997) Microsatellite DNA in fishes. Reviews in Fish Biology and Fisheries, 7, 331 - 363. Smith, P. J., Benson, P. G. & McVeagh, S. M. (1997) A comparison of three genetic methods used for stock discrimination of orange roughy, Hoplostethus atlanticus - allozymes, mitocondrial DNA, and random amplified polymorphic DNA. Fishery Bulletin, 95, 800-811. Wright, J. M. & Bentzen, P. (1995) Microsatellites: genetic markers for the future. In: Carvhalo, G. C. & Pitcher, T. J. (eds.) Molecular Genetics in Fisheries. Chapman & Hall, London. Objectives: 1. The objective of the present study is to determine whether selected assemblages of blue swimmer crabs in nearby and more distant regions in states throughout Australia are genetically different and thus constitute different stocks. The study will focus on determining the extent of any such differences and provide managers with an interpretation of the biological implications of those differences. Read moreRead less
Tactical Research Fund: Limiting Impacts Of The Spread Of Urchins By Rebuilding Abalone Populations
Funder
Fisheries Research and Development Corporation
Funding Amount
$42,000.00
Summary
The impact of urchins (i.e. Centrostephanus) on reef habitats in south-east Australia has been increasing for over a decade, and may be related to climate change (FRDC 2009/070). Urchins can clear and maintain areas of reef free from macro-algae, and reduce the productivity of abalone populations and other reef species. Extensive research projects to monitor urchin populations and reduce their impacts have been completed or are under-way in NSW, Victoria and Tasmania. There is an urgent need ....The impact of urchins (i.e. Centrostephanus) on reef habitats in south-east Australia has been increasing for over a decade, and may be related to climate change (FRDC 2009/070). Urchins can clear and maintain areas of reef free from macro-algae, and reduce the productivity of abalone populations and other reef species. Extensive research projects to monitor urchin populations and reduce their impacts have been completed or are under-way in NSW, Victoria and Tasmania. There is an urgent need to consolidate the findings of these research projects, and to quickly plan and coordinate the on-going development of responses to the spread of urchins.
There is evidence that production from commercial fisheries in NSW, Vic and Tas has been reduced by the spread of urchins. Small-scale clearance of urchins, and the translocation of abalone, has demonstrated the ability to recover abalone populations impacted by urchins, but consequent return of production has not yet been demonstrated in any fishery. In eastern Victoria, a joint project between Industry and Government has recently seen commercial-scale removal of urchins from previously-productive abalone reef, and the consequent recovery of appropriate habitat for abalone over a large-scale. There is now a tactical opportunity and strong need to take advantage of these removals before urchins re-invade, to demonstrate that past research can be scaled up to larger areas of reef and recovery of larger abalone populations, with the intent to maintain them over long-periods to demonstrate outcomes of sustained productivity.
Recent observations indicate urchins have also spread to western Victoria, where abalone are still recovering from Abalone Viral Ganglioneuritis. There is also an urgent need to both develop a survey to estimate the extent of Centrostephanus in western Victoria, and to investigate the potential of translocating abalone at a large-scale to re-establish populations in depleted areas, before urchins spread further.
Objectives: 1. Facilitate a workshop to coordinate existing research findings among jurisdictions, and plan further development and extension. 2. Implement the short-term outcomes of the workshop, particularly related to development of a survey to monitor spread of Centrostephanus. Read moreRead less