Meiotic recombination in Neurospora crassa: a model for the process in humans and other multicellular eukaryotes. Genes are shuffled by recombination during meiosis in the sexual cycle of higher organisms. This is best understood in yeast. Our findings show Neurospora recombination differs from yeast recombination. It is more tolerant of sequence mismatch, differs in the relative frequencies of gene conversion and crossing over, has frequently interrupted conversion tracts and has transacting ge ....Meiotic recombination in Neurospora crassa: a model for the process in humans and other multicellular eukaryotes. Genes are shuffled by recombination during meiosis in the sexual cycle of higher organisms. This is best understood in yeast. Our findings show Neurospora recombination differs from yeast recombination. It is more tolerant of sequence mismatch, differs in the relative frequencies of gene conversion and crossing over, has frequently interrupted conversion tracts and has transacting genes controlling recombination hotspot activity. We propose to genetically dissect Neurospora recombination which appears to be a closer model for recombination in humans and other higher eukaryotes, where understanding recombination can assist control of genetic disease, efficient breeding in agriculture and our understanding of evolution.Read moreRead less
Developmental regulation of plant mitochondrial genome structure and copy number. Recombination is a major driving force behind mitochondrial DNA evolution and is responsible for the occurrence of cytoplasmic male sterile plants that are used by plant breeders to obtain high yield hybrids. A better understanding of the mechanisms that underlie mitochondrial and chloroplast genome maintenance and segregation will be a major fundamental scientific advance that will permit an integrated picture of ....Developmental regulation of plant mitochondrial genome structure and copy number. Recombination is a major driving force behind mitochondrial DNA evolution and is responsible for the occurrence of cytoplasmic male sterile plants that are used by plant breeders to obtain high yield hybrids. A better understanding of the mechanisms that underlie mitochondrial and chloroplast genome maintenance and segregation will be a major fundamental scientific advance that will permit an integrated picture of the interactions between the three plant genomes (nuclear, mitochondrial and chloroplastic). It is also a pre-requisite for the future manipulation of the cytoplasmic genomes leading to new ways to develop varieties with modified cytoplasms.Read moreRead less
Integration of Cellular Gene Regulation Processes. This research program aims to identify specific transcriptional regulatory networks in yeast, to determine how some of these networks interact with each other and within these networks to identify the roles of genes whose functions are currently unknown. It will identify systems regulating genes concerned with one-carbon metabolism, cellular responses to oxidative stress and developmental changes associated with meiosis. It will provide a fra ....Integration of Cellular Gene Regulation Processes. This research program aims to identify specific transcriptional regulatory networks in yeast, to determine how some of these networks interact with each other and within these networks to identify the roles of genes whose functions are currently unknown. It will identify systems regulating genes concerned with one-carbon metabolism, cellular responses to oxidative stress and developmental changes associated with meiosis. It will provide a framework to test regulatory network models and to analyse the molecular basis of interactions between control systems. This research will eventually provide the ability to predict how cells respond to drugs and other environmental stimuli.Read moreRead less
A genomic approach to the mechanism of meiotic recombination in Neurospora. Recombination shuffles DNA sequences between homologous chromosomes during the reduction division in the life cycle of higher organisms. Along with mutation, it is a key process in evolution. Understanding of the molecular processes involved in recombination is largely based on yeast, which is intolerant of significant levels of sequence mismatch, limiting the resolution of analyses of normal recombination events. We hav ....A genomic approach to the mechanism of meiotic recombination in Neurospora. Recombination shuffles DNA sequences between homologous chromosomes during the reduction division in the life cycle of higher organisms. Along with mutation, it is a key process in evolution. Understanding of the molecular processes involved in recombination is largely based on yeast, which is intolerant of significant levels of sequence mismatch, limiting the resolution of analyses of normal recombination events. We have shown that Neurospora, like other less tractable multicellular eukaryotes, is tolerant of sequence mismatch, allowing high resolution analysis of individual recombination events. This project will build on fundamental advances we have already made in understanding how recombination occurs.Read moreRead less
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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How sexually antagonistic genes and sexual selection influence the evolution of the Y chromosome. Sexually antagonistic genes are beneficial to members of one sex, but costly to the other. They are of significance both to the coevolution between the sexes and the evolution of the sex chromosomes. We will measure the sexually antagonistic effects of genes that make male guppies sexually attractive. We will then study how these genes, and the process of sexual selection that favours them influence ....How sexually antagonistic genes and sexual selection influence the evolution of the Y chromosome. Sexually antagonistic genes are beneficial to members of one sex, but costly to the other. They are of significance both to the coevolution between the sexes and the evolution of the sex chromosomes. We will measure the sexually antagonistic effects of genes that make male guppies sexually attractive. We will then study how these genes, and the process of sexual selection that favours them influence the process of recombination between the X and Y chromosomes.Read moreRead less
Evolutionary genetics of bovid genomes over 60,000 years. This project will provide data critical for understanding the genetic background of modern cattle and bison, and how humans have shaped factors such as milk yield, growth rates and muscle mass. It will also reveal genes and genomic regions that were favoured in the domestication process, including those potentially linked to genes of commercial interest for future research. This pioneering ancient DNA approach will also be applicable to a ....Evolutionary genetics of bovid genomes over 60,000 years. This project will provide data critical for understanding the genetic background of modern cattle and bison, and how humans have shaped factors such as milk yield, growth rates and muscle mass. It will also reveal genes and genomic regions that were favoured in the domestication process, including those potentially linked to genes of commercial interest for future research. This pioneering ancient DNA approach will also be applicable to a variety of other domestic crops and animals. The unique temporal analysis of microevolution will provide crucial data for genetic research, and groundproof our attempts to analyse the timing and nature of human evolutionary history, major domestication events and inform conservation management.Read moreRead less
The Cytochrome P450 Gene Super-family in Drosophila melanogaster; Gene Function and Insecticide Resistance. The cytochrome P450 (Cyp) gene super-family is represented by over 90 sequences in the genome of the vinegar fly, Drosophila melanogaster. To date, four Cyp genes are found to be involved in insecticide resistance. The function of the majority of Cyp genes is unknown. This project will investigate the function and regulation of D. melanogaster Cyp genes, linking the fly's genotype to its ....The Cytochrome P450 Gene Super-family in Drosophila melanogaster; Gene Function and Insecticide Resistance. The cytochrome P450 (Cyp) gene super-family is represented by over 90 sequences in the genome of the vinegar fly, Drosophila melanogaster. To date, four Cyp genes are found to be involved in insecticide resistance. The function of the majority of Cyp genes is unknown. This project will investigate the function and regulation of D. melanogaster Cyp genes, linking the fly's genotype to its phenotype. By studying the effects of Cyp genes on fly survival, Cyp gene expression and regulation, and expressing selected Cyp genes in a yeast expression system, we will enhance our understanding of Cyp gene function and evolution.Read moreRead less
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
Choosing when to be sexual: clonal and sexual reproduction in a population of honey bees. Sex is costly. There is the cost of finding a mate and the genome of offspring must be shared with the mating partner. Despite these costs, sex is common in animals, so the benefits of sex must be substantial. Benefits may include the prevention of inbreeding and generating variable offspring. Exploring the trade off between sex and cloning requires a model system where individuals can choose to reproduce ....Choosing when to be sexual: clonal and sexual reproduction in a population of honey bees. Sex is costly. There is the cost of finding a mate and the genome of offspring must be shared with the mating partner. Despite these costs, sex is common in animals, so the benefits of sex must be substantial. Benefits may include the prevention of inbreeding and generating variable offspring. Exploring the trade off between sex and cloning requires a model system where individuals can choose to reproduce sexually or asexually. This project will explore a population of honey bees where a genetic mutation allows queens to clone themselves or reproduce sexually. We will reveal the unusual genetic mechanisms behind this ability and show how they are used by queens and workers to increase their reproductive success.Read moreRead less