Variation And Inheritance Of Retrotransposon Epigenotype In The Mouse
Funder
National Health and Medical Research Council
Funding Amount
$355,500.00
Summary
It is often assumed that traits in humans and other mammals are a product primarily of information encoded in the sequence of DNA, with some contribution from the environment. However, there is clear evidence that traits may vary widely between individuals with precisely the same DNA, such as identical twins, even in circumstances where environmental differences are negligible. This variation can be produced by epigenetic factors chemical changes or protein binding to DNA that alter the way gene ....It is often assumed that traits in humans and other mammals are a product primarily of information encoded in the sequence of DNA, with some contribution from the environment. However, there is clear evidence that traits may vary widely between individuals with precisely the same DNA, such as identical twins, even in circumstances where environmental differences are negligible. This variation can be produced by epigenetic factors chemical changes or protein binding to DNA that alter the way genes are used. Epigenetic factors can be passed from one generation to the next like the DNA itself, and this can make it difficult to know if a trait is encoded in the DNA itself or is epigenetic. We have found that some epigenetic traits in mice are caused by retrotransposons, which are parasitic elements that reside in and among genes, and can reproduce themselves, but do not have any known function (nearly half the human genome is made up of retrotransposons). Retrotransposons are generally kept silent by epigenetic factors, but may sometimes become active; when they do they may disturb normal patterns of gene activity and cause changes in traits and even disease. Much variation in humans may thus be due to variation in the epigenetic state (epigenotype) of retrotransposons. We propose to investigate variation and inheritance of epigenotype in mice, focussing on retrotransposons. We will use simple methods to compare epigenotype of a number of retrotransposons in genetically identical mice, and we will ask if any differences we find are heritable. We will also investigate the resetting of epigenotype the point in development when epigenetic factors are cleared and reset. We suspect that this occurs in early development. These studies may reveal a system of variation and inheritance with rules completely different from those found by Mendel, which may have a pervasive influence on traits, including sporadic diseases in humans.Read moreRead less
A Genome Wide Association Study For Endometriosis Susceptibility Genes
Funder
National Health and Medical Research Council
Funding Amount
$946,750.00
Summary
Endometriosis is a common condition that affects up to 10% of women. Symptoms are severe pelvic pain, menstrual problems and infertility with major impacts on women's lives and relationships. Since 1996, 4,000 affected women plus their families have joined our genetic study. Our aim is to conduct a genome wide search to identify genes contributing to endometriosis. This knowledge will ultimately lead to better diagnosis and treatment for the millions of women who suffer the disease.
Many recent gene mapping efforts have focused on population based approaches instead of previously used family based approaches. One of the limiting factors with population based approaches is the cost of the technology - each participant must be evaluated (or genotyped) for hundreds of thousands of genetic markers. The cost can be reduced by using an approach which pools individuals together for genotyping, with statistical models used to deal with the problems that this creates.
Identification And Characterisation Of The Genes And Pathways In Susceptibility To Inflammatory Bowel Disease
Funder
National Health and Medical Research Council
Funding Amount
$575,581.00
Summary
One of the greatest challenges facing contemporary genetics is to understand the genetics of complex diseases such as inflammatory bowel disease, mutiple sclerosis and schizophrenia. This application seeks to unravel the complex interactions between susceptibility genes and environmental triggers that work together to produce the inflammatory bowel diseases (IBD). Current estimates of the prevalence and incidence suggests that there may be 30-40,000 Australians who suffer from these chronic debi ....One of the greatest challenges facing contemporary genetics is to understand the genetics of complex diseases such as inflammatory bowel disease, mutiple sclerosis and schizophrenia. This application seeks to unravel the complex interactions between susceptibility genes and environmental triggers that work together to produce the inflammatory bowel diseases (IBD). Current estimates of the prevalence and incidence suggests that there may be 30-40,000 Australians who suffer from these chronic debiltating set of diseases known separately as Crohn's disease and ulcerative colitis. One susceptibility gene for Crohn's disease has been recently been identified and the project outlined will extend our knowledge not only to the susceptibility genes themselves, but also to the genes that interact with them to produce the disease via a cascade of immune and inflammatory events. This work is part of a large international effort to identify all IBD susceptibility genes and builds on the resources of the Australian IBD Familiy Register- an Australia wide register of families in which multiple members are affected by CD or UC. A traditional gene mapping approach is used in concert with mutiple analyses of different gene expression profiles in disease versus normal bowel tissues as well as in cell lines from patients versus controls. Validation studies include identification of the particular tissues and cell types that are involved in the pathological immune response typical of IBD as well as characterisation of specific patient genotypes and- or phenotypes that may correlate with expression profiles. Results obtained will be used to identify genes underlying IBD susceptibility, the mutations that drive the disease and eventually therapeutic targets for modulation and treatment of disease.Read moreRead less
Fine Scale Mapping And Identification Of The IBD1 Gene On Chromsosome 16
Funder
National Health and Medical Research Council
Funding Amount
$483,849.00
Summary
One of the greatest challenges facing contemporary gastroenterology is to understand the causes of the inflammatory bowel diseases (IBD). Studies on the prevalence, incidence and cost of IBD indicate that these diseases have considerable impact in Australia. On average, patients lose more than 13 days from work each year, and in hospital, IBD in-patients accounted for 7% of total admissions and 10% of total bed days at an average cost of $2600 per admission. We estimate that there may be more th ....One of the greatest challenges facing contemporary gastroenterology is to understand the causes of the inflammatory bowel diseases (IBD). Studies on the prevalence, incidence and cost of IBD indicate that these diseases have considerable impact in Australia. On average, patients lose more than 13 days from work each year, and in hospital, IBD in-patients accounted for 7% of total admissions and 10% of total bed days at an average cost of $2600 per admission. We estimate that there may be more than 10,000 Australians who suffer from IBD. The existence of a genetic predisposition to IBD is now well established, and there is strong evidence that the disease is complex, resulting from the interaction of a number of different genes. To date, one genetic localisation on chromosome 16 has been established in several different populations, and we have confirmed the importance of this localisation in the Australian population. We will further refine the localisation by fine scale mapping in the pericentromeric region of chromosome 16 by identifying and studying the inheritance of novel markers in the region. We will then identify and characterise the gene itself using several complementary appoaches that rely on differences at the molecular level between disease and normal tissue. This work is part of the international effort to identify all IBD susceptibility genes. Once that is achieved, approaches to explaining the interactions between the genes, their protein products and environmental triggers can be determined. Only when the mechanisms of these interactions are understood will the expectation of rational therapies based on an understanding of disease aetiology be possible.Read moreRead less