In this grant we aim to study the moecular basis of cancer. The promoter regions of tumour suppressor genes are often modified in cancer by a chemical process called methylation. Methylation of DNA is associated with gene silencing. Therefore DNA methylation is commonly regarded as causing the silencing of genes in cancer. In this grant, we aim to determine if methylation is causal in triggering gene silencing in cancer, or if methylation is a consequence of gene silencing. This is a critical di ....In this grant we aim to study the moecular basis of cancer. The promoter regions of tumour suppressor genes are often modified in cancer by a chemical process called methylation. Methylation of DNA is associated with gene silencing. Therefore DNA methylation is commonly regarded as causing the silencing of genes in cancer. In this grant, we aim to determine if methylation is causal in triggering gene silencing in cancer, or if methylation is a consequence of gene silencing. This is a critical distinction in understanding the role of methylation in cancer development.Read moreRead less
ARC Centre for Kangaroo Genome. In this Australian-led Kangaroo Genome Project, we will map and characterize the tammar wallaby genome at the molecular level. Marsupial genomes are uniquely valuable because they provide comparisons that reveal new human genes, regulatory sequences and marsupial-specific genes. These will deliver new products and information useful for medicine, industry, agriculture and conservation. We will construct integrated genetic and physical maps of the genome, clone the ....ARC Centre for Kangaroo Genome. In this Australian-led Kangaroo Genome Project, we will map and characterize the tammar wallaby genome at the molecular level. Marsupial genomes are uniquely valuable because they provide comparisons that reveal new human genes, regulatory sequences and marsupial-specific genes. These will deliver new products and information useful for medicine, industry, agriculture and conservation. We will construct integrated genetic and physical maps of the genome, clone the whole genome as large inserts in BAC vectors, and build a "golden path" with minimal overlap. We will construct libraries of expressed genes from tammar tissues and array them for use in analysing gene expression.Read moreRead less
New models for the role of chromatin in controlling inducible gene expression. This proposal aims to test novel models of how packaging of DNA in the nucleus plays a fundamental role in gene expression. Understanding these concepts is important in the context of successful gene therapy where major hurdles need to be overcome. This work also has implications for somatic cell therapy since it is important to understand how genes are expressed in order to successfully reprogram cells. Both of these ....New models for the role of chromatin in controlling inducible gene expression. This proposal aims to test novel models of how packaging of DNA in the nucleus plays a fundamental role in gene expression. Understanding these concepts is important in the context of successful gene therapy where major hurdles need to be overcome. This work also has implications for somatic cell therapy since it is important to understand how genes are expressed in order to successfully reprogram cells. Both of these areas are important to the Biotechnology industry. Answering questions about higher order chromatin structure in gene transcription will provide cutting edge, innovative knowledge that will have international significance. Read moreRead less
Inherited disorders of the blood, such as sickle-cell anaemia and thalassaemia, result from mutations in the genes that produce haemoglobin. Current treatments can partially alleviate some of the debilitating symptoms of these diseases but these treatments have significant side effects, and despite the best efforts of clinicians, many patients succumb to their conditions at an early age. It has been observed that certain individuals exhibit a milder form of the disease, as a consequence of the r ....Inherited disorders of the blood, such as sickle-cell anaemia and thalassaemia, result from mutations in the genes that produce haemoglobin. Current treatments can partially alleviate some of the debilitating symptoms of these diseases but these treatments have significant side effects, and despite the best efforts of clinicians, many patients succumb to their conditions at an early age. It has been observed that certain individuals exhibit a milder form of the disease, as a consequence of the reactivation of their foetal haemoglobin genes, (a distinct set of genes that would have been active in utero but are normally silenced around the time of birth). It is widely accepted that if pharmaceutical means can be found for reactivating the foetal haemoglobin genes then many patients would benefit. The regulation of the foetal globin genes, like most human genes, is complicated and there are few obvious means of increasing their activity. Nevertheless, it is believed that by investigating the molecular mechanisms by which they are controlled it will be possible to devise therapeutic agents that mimic these mechanisms or to develop agents that prevent the shutdown of the foetal genes around birth. To this end we have been working on the molecules that regulate the activity of the haemoglobin genes. We have recently cloned a number of DNA-binding proteins, and their co-factors, that appear to be involved in silencing foetal globin gene expression. This grant proposal is concerned with learning how these new molecules operate to silence gene expression as a first step towards designing agents that will prevent the silencing.Read moreRead less
Epigenetic Inheritance Through Meiosis At The Agouti Locus In Mice
Funder
National Health and Medical Research Council
Funding Amount
$182,699.00
Summary
The manifestations of many genetic traits do not conform to the rules of Mendelian inheritance. In humans, some alleles give a completely predictable phenotype, while others display a wide range of phenotypes, described as differences in penetrance and expressivity. As the phenotype associated with a particular gene in humans may be modified by the genotype at unlinked modifying loci and by environmental factors, it is difficult to determine to what extent any single factor is responsible for va ....The manifestations of many genetic traits do not conform to the rules of Mendelian inheritance. In humans, some alleles give a completely predictable phenotype, while others display a wide range of phenotypes, described as differences in penetrance and expressivity. As the phenotype associated with a particular gene in humans may be modified by the genotype at unlinked modifying loci and by environmental factors, it is difficult to determine to what extent any single factor is responsible for variability. In mice, however, a number of examples of variable expressivity have been reported in conditions where genetic background and environment have been controlled. For example, the phenotypes of mice with mutations at the agouti locus can vary substantially between genotypically identical littermates. Epigenetic modifications such as DNA methylation are known to be involved. Furthermore, the phenotypes of the offspring are related to the phenotype of the mother and recent experiments carried out in our laboratory suggest that this is the result of inheritance of the epigenetic state of the allele through the female germline. This is the first report of epigenetic inheritance at an endogenous gene in mammals. The experiments described in this project should help to clarify the mechanisms involved in variable expressivity and epigenetic inheritance. Variable expressivity in combination with epigenetic inheritance may be viewed as an alternative method of inheritance of genetic traits which does not involve DNA mutation, but which can be carried from generation to generation in a semipermanent way. Understanding the mechanisms underlying these phenomena is a challenge for contemporary genetics.Read moreRead less
Epigenetic silencing in vertebrates: evolution and function from the bottom-up. The primary benefits are contribution to Australia's knowledge base and raising the profile of functional genomics in Australia, with the research priority of Frontier Technologies for Building and Transforming Australian Industries and priority goals in Breakthrough Science and Frontier Technologies. This project focuses on important biological questions surrounding gene regulation and sex chromosome evolution. Inte ....Epigenetic silencing in vertebrates: evolution and function from the bottom-up. The primary benefits are contribution to Australia's knowledge base and raising the profile of functional genomics in Australia, with the research priority of Frontier Technologies for Building and Transforming Australian Industries and priority goals in Breakthrough Science and Frontier Technologies. This project focuses on important biological questions surrounding gene regulation and sex chromosome evolution. International attention has already resulted in genome characterization of Australian icons (wallaby, Tasmanian devil and platypus), more research on these, and other Australian animals, will further highlight the importance of Australian fauna and impact positively on our scientific profile.Read moreRead less
Origin and evolution of genes on the human X chromosome. Two groups of functionally related genes are found on the human X chromosome in disproportionately high numbers. I will test whether an uneven distribution of genes is common in mammalian genomes, or whether the human X is special. I will test hypotheses of how the gene groups arose on the human X by comparing their location and expression patterns in other mammals, and other vertebrates. It will then be clear whether the ancestral autosom ....Origin and evolution of genes on the human X chromosome. Two groups of functionally related genes are found on the human X chromosome in disproportionately high numbers. I will test whether an uneven distribution of genes is common in mammalian genomes, or whether the human X is special. I will test hypotheses of how the gene groups arose on the human X by comparing their location and expression patterns in other mammals, and other vertebrates. It will then be clear whether the ancestral autosome was ?chosen?, whether it ?selfishly? accumulated these genes, or whether the function of genes changed in response to selective pressures.Read moreRead less
Small is beautiful: Did gene-rich regions of mammal chromosomes evolve from microchromosomes? Most birds and reptile genomes feature many tiny microchromosomes. These are not junk, as previously thought, but contain most of the genes. Mammals lack microchromosomes, but contain gene-rich regions with similar attributes. We suggest that microchromosomes originated by genome duplication, and evolved into the gene-rich regions of mammalian chromosomes. We will test this hypothesis by comparing seque ....Small is beautiful: Did gene-rich regions of mammal chromosomes evolve from microchromosomes? Most birds and reptile genomes feature many tiny microchromosomes. These are not junk, as previously thought, but contain most of the genes. Mammals lack microchromosomes, but contain gene-rich regions with similar attributes. We suggest that microchromosomes originated by genome duplication, and evolved into the gene-rich regions of mammalian chromosomes. We will test this hypothesis by comparing sequences and genes in microchromosomes of birds, reptiles and monotremes. This will clarify the origin and evolution of the ?microgenome?, establish its suitability as a model for vertebrate genome organisation, and demonstrate whether microchromosomes are the ancestors of the gene-rich regions of mammalian chromosomes.Read moreRead less