Mechanism of higher-order chromatin formation and its role in controlling gene expression. The organization of genomic DNA into chromatin has solved one of the most difficult engineering problems required for the development of a multicellular organism; the compaction of over two meters DNA into a cell almost one millionth this size. Importantly, this compaction of the genome into chromatin has also been exploited by the cell to regulate the expression of genes. The aim of this investigation is ....Mechanism of higher-order chromatin formation and its role in controlling gene expression. The organization of genomic DNA into chromatin has solved one of the most difficult engineering problems required for the development of a multicellular organism; the compaction of over two meters DNA into a cell almost one millionth this size. Importantly, this compaction of the genome into chromatin has also been exploited by the cell to regulate the expression of genes. The aim of this investigation is to elucidate how genes are assembled into complex active or inactive chromatin structures by employing a novel in vitro system. This information will have important implications for gene therapy strategies.
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The Dynamic Control of Chromatin Structure. A human chromosome is a highly heterogeneous global structure because along its axis, it folds to different extents to form either highly compacted domains that repress the expression of genes or less condensed regions that enable genes to be turned on. Changes to the structure or stability of chromosomes, and the corresponding alterations to gene expression, have been linked to many diseases states like defects in human development and cancer. This s ....The Dynamic Control of Chromatin Structure. A human chromosome is a highly heterogeneous global structure because along its axis, it folds to different extents to form either highly compacted domains that repress the expression of genes or less condensed regions that enable genes to be turned on. Changes to the structure or stability of chromosomes, and the corresponding alterations to gene expression, have been linked to many diseases states like defects in human development and cancer. This study will uncover the underpinning mechanism of how our chromosomes are organised into distinct functional domains, which may offer the potential to develop new strategies to correct chromosomal abnormalities.
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Discovery of novel microRNA biogenesis and functional components. Discovery of novel microRNA components will provide new strategies for confronting a diverse array of challenges Australia faces, such as the increasing rates of certain cancers in our population, to stresses on our crop plants faced with environmental changes. The biological mechanisms underlying these disparate problems are unified by microRNA involvement in many instances. By finding microRNA controlling factors common to all h ....Discovery of novel microRNA biogenesis and functional components. Discovery of novel microRNA components will provide new strategies for confronting a diverse array of challenges Australia faces, such as the increasing rates of certain cancers in our population, to stresses on our crop plants faced with environmental changes. The biological mechanisms underlying these disparate problems are unified by microRNA involvement in many instances. By finding microRNA controlling factors common to all higher organisms, we expect our community will benefit from the increased knowledge base that will help our researchers adopt new strategies in fighting diseases and improving our agricultural industry.Read moreRead less
Controlling the rate of transcription and translation of Rubisco transgenes effectively in higher-plant plastids. Genetic transformation of the circular genome of the plastids provides a containable means for modifying plant growth by manipulating photosynthesis. Although the transformation mechanism is precise, predicting the level of foreign gene expression is difficult because the amounts of messenger RNA and protein produced by foreign genes in plastids varies widely, even when the protein a ....Controlling the rate of transcription and translation of Rubisco transgenes effectively in higher-plant plastids. Genetic transformation of the circular genome of the plastids provides a containable means for modifying plant growth by manipulating photosynthesis. Although the transformation mechanism is precise, predicting the level of foreign gene expression is difficult because the amounts of messenger RNA and protein produced by foreign genes in plastids varies widely, even when the protein assembles without difficulty. This project will devise strategies for controlling this variability that will facilitate attempts to exploit plastid transformation for transplanting better versions of the photosynthetic CO2-fixing enzyme, Rubisco, into plants to improve their growth efficiency in terms of water, fertiliser and light use.Read moreRead less
Practical strategies for engineering the CO2-fixing enzyme, Rubisco, whose subunits are encoded in different subcellular compartments. My recent replacement of the plant CO2-fixing enzyme, Rubisco, with a less efficient bacterial version, with a single type of subunit encoded by a single gene, demonstrated the feasibility of replacing Rubisco. This encourages ongoing attempts to replace plant Rubisco with more efficient versions that would allow the plants to grow with less water, fertiliser or ....Practical strategies for engineering the CO2-fixing enzyme, Rubisco, whose subunits are encoded in different subcellular compartments. My recent replacement of the plant CO2-fixing enzyme, Rubisco, with a less efficient bacterial version, with a single type of subunit encoded by a single gene, demonstrated the feasibility of replacing Rubisco. This encourages ongoing attempts to replace plant Rubisco with more efficient versions that would allow the plants to grow with less water, fertiliser or light. The most efficient Rubiscos are more complex, with two different types of subunits which, in plants, are encoded in different subcellular compartments (nucleus and plastid). This proposal addresses the challenges associated with complementary engineering both genomes to substitute foreign Rubiscos into higher-plant chloroplasts.Read moreRead less
Genetic control of floral architecture. Different flowers have different designs, and so the design must ultimately be controlled by genes. We have identified a gene that keeps sepals separate, and promotes the initiation of petals. We think it does this by a novel growth suppression mechanism, and will now deduce its molecular and cellular basis. This will help maintain Australia's strength in fundamental plant biology. Also, by understanding how sepals and petals arise in a model laboratory sp ....Genetic control of floral architecture. Different flowers have different designs, and so the design must ultimately be controlled by genes. We have identified a gene that keeps sepals separate, and promotes the initiation of petals. We think it does this by a novel growth suppression mechanism, and will now deduce its molecular and cellular basis. This will help maintain Australia's strength in fundamental plant biology. Also, by understanding how sepals and petals arise in a model laboratory species, we can generalise for many species, including economic plants. Thus it may be possible to make designer crops through targeted genetic changes to their floral structure.Read moreRead less
Control of plant organ development by the PETAL LOSS gene of Arabidopsis. We have discovered a new gene in the model laboratory plant Arabidopsis thaliana that is involved in sepal and petal development. It encodes a transcription factor that apparently acts by repressing growth in the inter-sepal zone of flowers where petals arise. We now aim to determine how this growth suppression occurs, and whether it extends to leaves where the gene is also expressed. Control of the initiation and sculptur ....Control of plant organ development by the PETAL LOSS gene of Arabidopsis. We have discovered a new gene in the model laboratory plant Arabidopsis thaliana that is involved in sepal and petal development. It encodes a transcription factor that apparently acts by repressing growth in the inter-sepal zone of flowers where petals arise. We now aim to determine how this growth suppression occurs, and whether it extends to leaves where the gene is also expressed. Control of the initiation and sculpturing of plant organs by site-specific inhibition of growth is a newly discovered mechanism that may be useful in manipulating plant architecture.Read moreRead less
Understanding how auxin and dorsoventral patterning are coordinated in plants. This study will help reveal for the first time how the outgrowth of leaves, flowers and floral organs is coordinated by tissue patterning genes and the plant growth hormone auxin. All plants grow in this way, and our findings, made using a model laboratory plant, will be applicable to crop species as well. Thus we will both expand our core knowledge of how multicellular organisms are constructed, and also generate pos ....Understanding how auxin and dorsoventral patterning are coordinated in plants. This study will help reveal for the first time how the outgrowth of leaves, flowers and floral organs is coordinated by tissue patterning genes and the plant growth hormone auxin. All plants grow in this way, and our findings, made using a model laboratory plant, will be applicable to crop species as well. Thus we will both expand our core knowledge of how multicellular organisms are constructed, and also generate possibilities for modifying the patterns of leaf and flower development in agricultural and horticultural species. Crops with larger leaves, or flowers of different structure, may result.Read moreRead less
Adaptive Evolution of BRCA1 in Ancestral Mammals. This project investigates adaptive evolution of BRCA1 in the early radiation of mammals. We will test the hypothesis that the evolution of mammary glands and X chromosome inactivation has resulted in modification of the BRCA1 protein sequence as it aquired new roles in these processes. We will also investigate the importance of these changes inducing compensatory changes in other parts of the protein.
Molecular and genetic analysis of epigenetic components in a model plant. Australia is a major exporter of agricultural food crops thus producers must maintain their competitive advantage in order to compete on the world stage. Food crops unfortunately have large, complex genomes that are not sequenced and a generation time of months that makes research outcomes slow to achieve. This project proposes to utilise a model plant that has a small completely sequenced genome and a short generation tim ....Molecular and genetic analysis of epigenetic components in a model plant. Australia is a major exporter of agricultural food crops thus producers must maintain their competitive advantage in order to compete on the world stage. Food crops unfortunately have large, complex genomes that are not sequenced and a generation time of months that makes research outcomes slow to achieve. This project proposes to utilise a model plant that has a small completely sequenced genome and a short generation time making it ideal to study the fundamental biological process of RNA silencing. Discoveries and outcomes from this project may have the potential to benefit Australian crops, ecosystems and human health.Read moreRead less