Solving the Mysteries of Monotreme Chromosomes. The peculiar chromosomes of Australia's platypus and echidna have been debated for more than 30 years. Classical cytology cannot resolve the puzzling sex chromosome system, or to sort out the bizarre translocation chain (unique in vertebrates) and deduce how it segregates to make viable zyotes. I will microdissect individual chromosomes, and use DNA ?paints? from them (and gene probes isolated by them) to detect homologies between unpaired chromoso ....Solving the Mysteries of Monotreme Chromosomes. The peculiar chromosomes of Australia's platypus and echidna have been debated for more than 30 years. Classical cytology cannot resolve the puzzling sex chromosome system, or to sort out the bizarre translocation chain (unique in vertebrates) and deduce how it segregates to make viable zyotes. I will microdissect individual chromosomes, and use DNA ?paints? from them (and gene probes isolated by them) to detect homologies between unpaired chromosomes at mitosis, meiosis and in sperm. I will use immunohistochemistry to clarify chromosome pairing and recombination at meiosis. This will answer some important general questions about chromosome behaviour and sex chromosome evolution.
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Many Ys in monotremes: multiple sex chromosomes and sex determination in platypus and echidna. Platypus and Echidna are Australian icons, even featuring on our coins. Their unusual biology and ancient relationship to humans make them unique for understanding the mammalian genome, as demonstrated by our recent discovery of ten sex chromosomes in platypus that link mammal and bird sex. Still little is known about their genome, embryo development and how sex is determined. We will identify new gene ....Many Ys in monotremes: multiple sex chromosomes and sex determination in platypus and echidna. Platypus and Echidna are Australian icons, even featuring on our coins. Their unusual biology and ancient relationship to humans make them unique for understanding the mammalian genome, as demonstrated by our recent discovery of ten sex chromosomes in platypus that link mammal and bird sex. Still little is known about their genome, embryo development and how sex is determined. We will identify new genes on all ten sex chromosomes and investigate how they determine sex. The set up of an Australian Monotreme Resource Centre will be crucial for this research and attract worldwide high profile collaborations. We will answer important general questions in monotreme biology and contribute to our understanding of sexual abnormalities in humans.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
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0561030
Funder
Australian Research Council
Funding Amount
$441,100.00
Summary
Developmental Imaging Facility. This application seeks to establish a facility to undertake expression profiling in vertebrate tissues on a genomic scale and at the highest resolution. Undertaking large scale projects of this nature requires specialised robotics and dedicated infrastructure for microscopy and tissue preparation. This facility will be the first of its type in Australia will permit researchers to perform genomic scale in situ screens, many as part of large international initiative ....Developmental Imaging Facility. This application seeks to establish a facility to undertake expression profiling in vertebrate tissues on a genomic scale and at the highest resolution. Undertaking large scale projects of this nature requires specialised robotics and dedicated infrastructure for microscopy and tissue preparation. This facility will be the first of its type in Australia will permit researchers to perform genomic scale in situ screens, many as part of large international initiatives in developmental and cellular biology. This large-scale, high-resolution expression profiling infrastructure is required to maintain international competitiveness and will dramatically improve our gene discovery, functional assessment and understanding of vertebrate development.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
The role of the neuronal Hu proteins in the regulation of the BMP signalling pathway. We aim to understand the critical decision of a neural progenitor to commit to becoming a neuron. The BMP signalling pathway is central in this decision. Neural progenitors appear to become insensitive to BMP signals, and this lack of signalling leads to neuronal differentiation. We hypothesise that neuronal identity is regulated by an unusual genetic switch- the translational regulation by the neuronal Hu pr ....The role of the neuronal Hu proteins in the regulation of the BMP signalling pathway. We aim to understand the critical decision of a neural progenitor to commit to becoming a neuron. The BMP signalling pathway is central in this decision. Neural progenitors appear to become insensitive to BMP signals, and this lack of signalling leads to neuronal differentiation. We hypothesise that neuronal identity is regulated by an unusual genetic switch- the translational regulation by the neuronal Hu proteins of two proteins in the BMP pathway. Verification of a post-transcriptional regulatory mechanism for cell fate determination would be a major discovery, and may prompt investigation of how to harness the neuron-inducing function of the Hu proteins to address the therapeutic need for new neurons in neurologic diseases.Read moreRead less
Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0775503
Funder
Australian Research Council
Funding Amount
$255,000.00
Summary
Robotics for plant genomics: Increasing throughput in plant genetic analyses. Plant genomics has direct benefit to crop improvement, especially as focussed in the applicants' laboratories. Thus, the Australian agri-food sector will benefit substantially from the acceleration in plant functional genomics that will arise from the installation of the robotics equipment described in the current application, by both underpinning more applied research and also being used directly in crop improvement p ....Robotics for plant genomics: Increasing throughput in plant genetic analyses. Plant genomics has direct benefit to crop improvement, especially as focussed in the applicants' laboratories. Thus, the Australian agri-food sector will benefit substantially from the acceleration in plant functional genomics that will arise from the installation of the robotics equipment described in the current application, by both underpinning more applied research and also being used directly in crop improvement programs such as are based at the Waite Campus. The outputs will include crops with increased tolerance to biotic and abiotic stresses, a reduced dependence on chemical inputs such as fertilisers and improved food quality, with consequent benefits to the environment and human health and nutrition.Read moreRead less
Endosymbiotic DNA transfer. Interorganellar DNA movement is a major force in evolution. In higher organisms, the prokaryotic ancestors of mitochondria and chloroplasts donated many genes to the nucleus. Plants have unique potential in studies of the mechanisms that have driven genome evolution. We established experimentally that DNA moves from the chloroplast to the nucleus at high frequency and this provided us with a world lead in this scientifically new area. The relocated genes contribute to ....Endosymbiotic DNA transfer. Interorganellar DNA movement is a major force in evolution. In higher organisms, the prokaryotic ancestors of mitochondria and chloroplasts donated many genes to the nucleus. Plants have unique potential in studies of the mechanisms that have driven genome evolution. We established experimentally that DNA moves from the chloroplast to the nucleus at high frequency and this provided us with a world lead in this scientifically new area. The relocated genes contribute to the number and diversity of genes and gene function. Genetically manipulated (GM) crops use the chloroplast compartment to make high levels of protein, necessitating a full understanding of how transgenes behave within the cellular and the external environment.Read moreRead less