Understanding the evolution of the alternation of generations in the land plant life cycle. This project will investigate the genetic basis and evolution of the land plant life cycle, in which both haploid and diploid phases consist of complex multicellular bodies. The project's findings, which will be made using two model laboratory plants, will be applicable to all plants and will help understand important processes such as pollen and seed production.
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
Gene-environment interactions in reptile sex determination. Sex in many reptiles-crocodiles, marine and freshwater turtles, lizards, tuatara-depends on temperature in the nest. This project will examine poorly understood interactions between genes and temperature in determining sex expanding knowledge of how reptiles with temperature dependent sex determination can evolve to accommodate environmental change.
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
Discovering sex determining genes in a reptile with genetic and environmental sex determination. Reptile sex determination is particularly fascinating because it is triggered either by genes on sex chromosomes or by the nest temperature. This project will identify and characterise candidate sex determining genes in a model reptile to understand how genes control sexual differentiation and how they interact with temperature.
Was an ancient bird-like sex chromosome system ancestral to reptiles and mammals? Recent discoveries reveal amazing similarity in the sex chromosomes of distantly related animals. This project will use advanced DNA technology to explore diverse sex chromosomes in reptiles to discover whether this signifies ancient and unsuspected common ancestry, or the convergent redeployment of genes and chromosomes predisposed to determine sex.
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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