Genetic analysis of two distinct reproductive strategies in sexual and thelytokous field populations of an endoparastic wasp. Asexual (thelytokous) females of an insect parasitoid, Venturia canescens, which develop inside another insect, exhibit evolutionarily stable mixtures of life-history strategies, allowing two genetically distinct wasp lines to coexist sympatrically on the same host resources. The two thelytokous lines differ in a virus-like particle protein-coding gene (VLP1), which raise ....Genetic analysis of two distinct reproductive strategies in sexual and thelytokous field populations of an endoparastic wasp. Asexual (thelytokous) females of an insect parasitoid, Venturia canescens, which develop inside another insect, exhibit evolutionarily stable mixtures of life-history strategies, allowing two genetically distinct wasp lines to coexist sympatrically on the same host resources. The two thelytokous lines differ in a virus-like particle protein-coding gene (VLP1), which raises the question whether the VLP1 gene locus is genetically associated with the phenotype. We will investigate the genetic basis for the observed phenotypic differences, by comparing the two thelytokous lines with the corresponding homozygous VLP1-genotypes in sexual strains. The outcome will provide a molecular and genetic framework to test parthenogenetic reproduction strategies in some insect species.Read moreRead less
Genetic dissection of a regulatory deubiquitlyation network. The potential impact of this work is widespread, because although it is known that ubiquitlyation has regulatory consequences in multicellular eukaryotes, individual networks have not been completely described in higher eukaryotes. Knowledge gained about fundamental processes in the A. nidulans model system is directly applicable to fungi used in biotechnology in the food, beverage, enzyme and pharmaceutical production industries, and ....Genetic dissection of a regulatory deubiquitlyation network. The potential impact of this work is widespread, because although it is known that ubiquitlyation has regulatory consequences in multicellular eukaryotes, individual networks have not been completely described in higher eukaryotes. Knowledge gained about fundamental processes in the A. nidulans model system is directly applicable to fungi used in biotechnology in the food, beverage, enzyme and pharmaceutical production industries, and to fungal pathogens. Since the fungal genes that form the basis of this project are conserved in higher eukaryotes including humans, the knowledge will be transferable to these systems. A further benefit that cannot be overstated is the research education and training opportunities provided.
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Is regressive evolution associated with loss of gene function in subterranean animals? This project aims to investigate a fundamental biological process: the evolutionary basis for how non-functional characters, such as eyes in subterranean animals, are lost. It will use a unique model system based on eyeless water beetles, and utilise novel new genomic tools to test whether loss of characters results from gene inactivation.
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
Why do only some exotics become invasive? Combining ecological and genomic approaches to address alternative hypotheses in a recent Australian weed. This project will specifically test alternative hypotheses about how weeds become invasive. As invasive weeds affect both agricultural and native ecosystems equally, research on understanding the mechanisms of weed invasion is critical. Outcomes will benefit Australia by allowing better prioritisation of management against exotic plants already i ....Why do only some exotics become invasive? Combining ecological and genomic approaches to address alternative hypotheses in a recent Australian weed. This project will specifically test alternative hypotheses about how weeds become invasive. As invasive weeds affect both agricultural and native ecosystems equally, research on understanding the mechanisms of weed invasion is critical. Outcomes will benefit Australia by allowing better prioritisation of management against exotic plants already in the country by providing predictive tools to estimate likelihood of spread. For formal Pest Risk Analysis by regulators (eg Biosecurity Australia), our project will provide genomic tools by which the potential weediness of a regulated plant can be assessed through genetic screening, and forms part of an international effort to identify 'weedy genes'. Read moreRead less
Discovery Early Career Researcher Award - Grant ID: DE150100091
Funder
Australian Research Council
Funding Amount
$341,000.00
Summary
Traffic on DNA: interplay between RNA polymerases and DNA-bound proteins. The DNA inside the cell is not just a repository of information, but is an active player in how that information is used. Proteins bind to defined locations on the DNA to control which genes are active, and genes are expressed by RNA polymerases that track along the DNA. Collisions between RNA polymerases and DNA-bound proteins can remove the proteins or block the polymerase. How can these essential processes safely coexis ....Traffic on DNA: interplay between RNA polymerases and DNA-bound proteins. The DNA inside the cell is not just a repository of information, but is an active player in how that information is used. Proteins bind to defined locations on the DNA to control which genes are active, and genes are expressed by RNA polymerases that track along the DNA. Collisions between RNA polymerases and DNA-bound proteins can remove the proteins or block the polymerase. How can these essential processes safely coexist on the DNA? The project aims to integrate systematic experiments using well-defined genetic components and mathematical modelling to understand the 'design' features of DNA and proteins that minimise these traffic problems. A better understanding could inform new strategies for manipulation of gene expression.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
A study of the nongenomic action of Vitamin D: proposed role of the nuclear VDR and downstream signalling molecules. Vitamin D (1,25D) activates genes in the nucleus through the vitamin D receptor (VDR). 1,25D can also elicit rapid responses at the plasma membrane. This action is critical to the activation of nuclear genes. We hypothesise that a proportion of the nuclear VDR is located at the plasma membrane where it stimulates downstream signalling molecules eg Ras, ERK1/2 and ERK5. We plan to ....A study of the nongenomic action of Vitamin D: proposed role of the nuclear VDR and downstream signalling molecules. Vitamin D (1,25D) activates genes in the nucleus through the vitamin D receptor (VDR). 1,25D can also elicit rapid responses at the plasma membrane. This action is critical to the activation of nuclear genes. We hypothesise that a proportion of the nuclear VDR is located at the plasma membrane where it stimulates downstream signalling molecules eg Ras, ERK1/2 and ERK5. We plan to explore this hypothesis and to identify the signalling molecules. We will also investigate our novel finding that a specific Ras isoform is involved in ERK5 activation. The work will provide new information on signalling pathways.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
Road rules for traffic on DNA - gene regulation by encounters between transcribing RNA polymerases and DNA-bound proteins. This project addresses a widespread but poorly understood phenomenon in gene regulation. The work will support Australian industries by supplying new tools for manipulation of gene expression for industrial and medical applications and will provide unique opportunities for Australian students in this emerging field.