Trafficking of DNA between chloroplast and nucleus in higher plants. Reliably high levels of diverse proteins can be produced in plant chloroplasts. Environmental risks are considered low for chloroplast genes because they are not transmitted by pollen. However, we recently discovered that DNA escapes from the tobacco chloroplast to the nucleus with unexpectedly high frequency. The associated environmental risks require immediate investigation. This project will determine the fate of chloroplast ....Trafficking of DNA between chloroplast and nucleus in higher plants. Reliably high levels of diverse proteins can be produced in plant chloroplasts. Environmental risks are considered low for chloroplast genes because they are not transmitted by pollen. However, we recently discovered that DNA escapes from the tobacco chloroplast to the nucleus with unexpectedly high frequency. The associated environmental risks require immediate investigation. This project will determine the fate of chloroplast DNA that has moved to the nuclear genome and gain insight into the evolutionary and environmental consequences of chloroplast DNA escape. The ubiquity of DNA escape also will be studied in an edible crop with a small genome, tomato.Read moreRead less
Analysis of interorganellar transposition of DNA. The movement of DNA between organelles is a major driving force in the eukaryotic evolution. In yeast about 75% of all nuclear genes may derive from protomitochondria. Though DNA transfer per se continues in all higher cells, including mammals, in most species the functional transfer of genes has stopped. It continues at a high rate in plants, giving them unique potential in evolutionary studies of the genome. We established experimentally that D ....Analysis of interorganellar transposition of DNA. The movement of DNA between organelles is a major driving force in the eukaryotic evolution. In yeast about 75% of all nuclear genes may derive from protomitochondria. Though DNA transfer per se continues in all higher cells, including mammals, in most species the functional transfer of genes has stopped. It continues at a high rate in plants, giving them unique potential in evolutionary studies of the genome. We established experimentally that DNA moves frequently from the plastid (chloroplast) to the nucleus. We now aim to measure the frequency of DNA transposition from the plastid to the mitochondrion. If transposition is sufficiently frequent, the approach can be used to transformation the mitochondrial genome.Read moreRead less
The molecular basis of endosymbiotic evolution. First: Timmis has a 20 year, pioneering reputation in this research area which has recently emerged as a major focus in evolutionary genetics, genomics and GM crop technology. Four years of recent ARC funding has enabled us to remain internationally competitive and significant papers and collaborative reviews in high-impact journals have resulted, to the benefit of Australia's reputation in biolological science. Second: our recent results have caus ....The molecular basis of endosymbiotic evolution. First: Timmis has a 20 year, pioneering reputation in this research area which has recently emerged as a major focus in evolutionary genetics, genomics and GM crop technology. Four years of recent ARC funding has enabled us to remain internationally competitive and significant papers and collaborative reviews in high-impact journals have resulted, to the benefit of Australia's reputation in biolological science. Second: our recent results have caused major debate about containment of GM crops. The knowledge gained from this research will provide essential information to ensure against environmental and human problems associated with transgene escape from GM crops into wild species.Read moreRead less
Monotreme immune system provides insights into their evolutionary relationships. Genes of immunological importance will be cloned and characterised from the short-beaked echidna with the purpose of investigating the immune system in monotremes, gaining insights into the timing and order of evolutionary separation of the three extant mammalian groups:- the Prototherians (monotremes), the Metatherians (marsupials) and Eutherians (placentals), increasing understanding of the evolution of the verteb ....Monotreme immune system provides insights into their evolutionary relationships. Genes of immunological importance will be cloned and characterised from the short-beaked echidna with the purpose of investigating the immune system in monotremes, gaining insights into the timing and order of evolutionary separation of the three extant mammalian groups:- the Prototherians (monotremes), the Metatherians (marsupials) and Eutherians (placentals), increasing understanding of the evolution of the vertebrate immune system and providing the basis for making immunological reagents which are necessary for studying monotreme diseases (as a precautionary conservation strategy).Read moreRead less
Enhanced biocatalysis in organic solvents for pharmaceutical biotransformation. Enzymes such as hydrolases play an important role in biotechnology because of their extreme versatility with respect to substrate specificity and stereoselectivity. The use of lipases as catalysts for optical isomer-specific organic reactions is often limited by unacceptably low enantioselectivities. We will investigate recombinant enzymes cloned from thermophilic lipolytic bacteria for synthetic reactions in orga ....Enhanced biocatalysis in organic solvents for pharmaceutical biotransformation. Enzymes such as hydrolases play an important role in biotechnology because of their extreme versatility with respect to substrate specificity and stereoselectivity. The use of lipases as catalysts for optical isomer-specific organic reactions is often limited by unacceptably low enantioselectivities. We will investigate recombinant enzymes cloned from thermophilic lipolytic bacteria for synthetic reactions in organic solvents, especially chiral resolution of mixtures in the production of pharmaceutical intermediates. Genetic improvement of lipase enantiospecificity and regioselectivity will be achieved using in vitro evolution by recombination and screening. The outcome will be cost-effective production superior biocatalysts with specifically enhanced regiospecific, enantioselective and hydrolytic characteristics.
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Evolution in microsatellite DNA: testing models of mutation in an Australian marsupial. We aim to compare mutational events between microsatellite loci that vary in their exposure to recombination. We are able to do this because of a remarkable finding that Australian brushtail possums have multiple occurrences of a single microsatellite repeat element within the Y-chromosome and among autosomal loci. We will compare variation between the Y-linked and non Y-linked loci within and among individu ....Evolution in microsatellite DNA: testing models of mutation in an Australian marsupial. We aim to compare mutational events between microsatellite loci that vary in their exposure to recombination. We are able to do this because of a remarkable finding that Australian brushtail possums have multiple occurrences of a single microsatellite repeat element within the Y-chromosome and among autosomal loci. We will compare variation between the Y-linked and non Y-linked loci within and among individual possums and use those comparisons to distinguish between recombinant and non- recombinant mutational mechanisms. These data will provide new insights into the mutational mechanisms that drive variation in these most important molecular markers.Read moreRead less
Sex in Dragons: Evolution of sex determination in reptiles. Australia is a leader in sex determination research with major advances in our understanding attributable to Australian researchers and laboratories. This project will contribute to our prestige as a nation capable of contributing cutting edge research directions and stimulating ideas in human sex determination. Moreover, many reptiles have temperature-dependent sex determination, and so would appear appallingly vulnerable to climate ch ....Sex in Dragons: Evolution of sex determination in reptiles. Australia is a leader in sex determination research with major advances in our understanding attributable to Australian researchers and laboratories. This project will contribute to our prestige as a nation capable of contributing cutting edge research directions and stimulating ideas in human sex determination. Moreover, many reptiles have temperature-dependent sex determination, and so would appear appallingly vulnerable to climate change. Our project, will bring improved understanding of sex determination in reptiles, identify evolutionary responses of reptiles to climate change, and assist by informing society on how we might manage this issue into the future conservation of these unique Australian reptiles. Read moreRead less
Sex in Dragons: The molecular basis of genetic and environmental sex determination. How animals determine sex has been debated over decades. Particularly mysterious is that sex is determined by genes in some animals, and by temperature in others. We will study closely related dragon lizards which determine sex via genes (GSD) or temperature (TSD). We will use novel genetic, molecular and cytological aproaches to discover genes and chromosomes that control sex determination in the GSD species, an ....Sex in Dragons: The molecular basis of genetic and environmental sex determination. How animals determine sex has been debated over decades. Particularly mysterious is that sex is determined by genes in some animals, and by temperature in others. We will study closely related dragon lizards which determine sex via genes (GSD) or temperature (TSD). We will use novel genetic, molecular and cytological aproaches to discover genes and chromosomes that control sex determination in the GSD species, and explore their homologues in the TSD species. We expect this study will provide new insights to mechanisms of sex determination in all vertebrates, and demonstrate how genes and the environment interact to control the process.Read moreRead less
Organization, function and evolution of marsupial Y chromosomes. The Y chromosome of humans and other mammals contains only a few genes, most specialized for male sex and reproduction. How the Y chromosome evolved to be so peculiar has been debated for 90 years. It began as an ordinary chromosome, but has degraded until there is almost nothing left, and it is likely to disappear in about 13 million years. Molecular characterization of the Y chromosomes of distantly related mammals could serve to ....Organization, function and evolution of marsupial Y chromosomes. The Y chromosome of humans and other mammals contains only a few genes, most specialized for male sex and reproduction. How the Y chromosome evolved to be so peculiar has been debated for 90 years. It began as an ordinary chromosome, but has degraded until there is almost nothing left, and it is likely to disappear in about 13 million years. Molecular characterization of the Y chromosomes of distantly related mammals could serve to 're-run the evolutionary tape', but the Y chromosome has been left out of whole genome sequencing because it is hard to do efficiently. We developed a novel technique to isolate DNA sequences and genes on the Y chromosome in three species of marsupials, which are especially valuable because they are so different from human and mouse.Read moreRead less
Sex in Dragons: Probing the genotype-phenotype interaction in sex determination. Reptiles have two modes of sex determination: genetic (GSD) and temperature dependent (TSD). We will determine if there is an underlying mechanism of sex determination common to TSD and GSD reptiles by comparing the genomes of two sister species of dragon lizard that differ in their mode of sex determination. This study will provide new insights to the mechanism of sex determination in vertebrates and will test the ....Sex in Dragons: Probing the genotype-phenotype interaction in sex determination. Reptiles have two modes of sex determination: genetic (GSD) and temperature dependent (TSD). We will determine if there is an underlying mechanism of sex determination common to TSD and GSD reptiles by comparing the genomes of two sister species of dragon lizard that differ in their mode of sex determination. This study will provide new insights to the mechanism of sex determination in vertebrates and will test the proposition that sex determination results from the interaction between environmental influences and an underlying genetic component.Read moreRead less