Histone H3.3 Dynamics At The Telomere In Pluripotent Embryonic Stem Cells
Funder
National Health and Medical Research Council
Funding Amount
$571,977.00
Summary
The telomere is required for the protection of the chromosome ends. Telomere loses its repeat during each cell division, so telomere shorthening is one of the mechanisms underlying organismal aging as critically short telomeres induce chromosome instability and cell death. Defective telomeres can also result in genetic diseases and development of cancers. Here, we propose to study the mechanism that operates to ensure continual telomere renewal without senescence in embryonic stem cells.
Regulation And Role Of Transcription At The Centromere.
Funder
National Health and Medical Research Council
Funding Amount
$737,801.00
Summary
Every human cell has 46 chromosomes. Chromosomes are structures that carry genes in all our cells. The centromere is an essential component of a chromosome. It controls the process of cell division, and it ensures the equal division of the duplicated chromosomes. Defects in centromere function can result in various genetic diseases and development of cancers. The structure of the centromere is unique and its properties are determined by an array of proteins and other as yet unknown factors that ....Every human cell has 46 chromosomes. Chromosomes are structures that carry genes in all our cells. The centromere is an essential component of a chromosome. It controls the process of cell division, and it ensures the equal division of the duplicated chromosomes. Defects in centromere function can result in various genetic diseases and development of cancers. The structure of the centromere is unique and its properties are determined by an array of proteins and other as yet unknown factors that bind to it. In our preliminary work, we have demonstrated that a novel non-protein component in the form of RNA (which are expressed products of genes) is essential for the binding of key proteins to the centromere. The presence and importance of such an RNA component has not been previously suspected and represents an exciting new mechanism that help to determine the functional and structural integrity of the centromere. In this project, we propose to study the details of this RNA and to define how this RNA-related mechanism operates to ensure the proper assembly and function of the centromere during cell division.Read moreRead less
The Role Of Centromere Proteins In Centromere Assembly, Chromosome Instability, And Cancer
Funder
National Health and Medical Research Council
Funding Amount
$687,750.00
Summary
Our genetic information are organised into compact structures known as chromosomes in our cells. Each human cell has 46 chromosomes. Excess or insufficient copies of these chromosomes will cause genetic imbalance that often results in serious clinical problems such as Down syndrome, cancer, embryonic death, and a host of other syndromes. The study of the process of how the exact number of chromosomes is distributed amongst daughter cells when cells divide is therefore an important area of resear ....Our genetic information are organised into compact structures known as chromosomes in our cells. Each human cell has 46 chromosomes. Excess or insufficient copies of these chromosomes will cause genetic imbalance that often results in serious clinical problems such as Down syndrome, cancer, embryonic death, and a host of other syndromes. The study of the process of how the exact number of chromosomes is distributed amongst daughter cells when cells divide is therefore an important area of research. Our laboratory has focused research on a key structure of the chromosome known as the centromere that determines how this process is controlled. The present project aims to study the properties of the centromere in detail using the technique of targeted gene mutation in mice. In these mice, the functions of individual genes that make specific centromere proteins are destroyed or modified through a precisely controlled mutation process. The effects such mutations have on the development of the animals and on chromosome division can then be analysed in great detail. The outcome will be a significant increase in our understanding of the functions of the different centromere proteins, an understanding that is key to the further advancement of our knowledge on the aetiology of some of the most frequently seen disease conditions in humans, including cancer.Read moreRead less
Spatial Arrangement And Three-dimensional Structure Of Human Centromeres
Funder
National Health and Medical Research Council
Funding Amount
$283,000.00
Summary
Centromeres occur at the main constriction of chromosomes. They allow duplicated chromosomes to divide, control cell division and are involved in the control of gene expression. Faulty centromeres are found in many types of cancer and in other genetic diseases. They are also implicated in extra-chromosome disorders such as Down syndrome. Centromeres have a different structure to the rest of the chromosome and it is this structure we wish to study. We want to see how centromere DNA folds up tight ....Centromeres occur at the main constriction of chromosomes. They allow duplicated chromosomes to divide, control cell division and are involved in the control of gene expression. Faulty centromeres are found in many types of cancer and in other genetic diseases. They are also implicated in extra-chromosome disorders such as Down syndrome. Centromeres have a different structure to the rest of the chromosome and it is this structure we wish to study. We want to see how centromere DNA folds up tightly at the centromere. We also want to find out why centromeres locate in certain regions of the nucleus, because this may influence how the centromere works and how they regulate genes. Human centromeres come in many sizes and forms; by looking at a wide range of human centromeres, common structural and spatial properties will emerge. We have discovered very small centromeres - neocentromeres - which are much easier to study than other centromeres. We have used these centromeres to construct human minichromosomes, which we believe represent the main, all-human way forward to treat people with gene therapy. One way to help us achieve our aims is to stretch out centromeres in a controlled way to make it easier to visualise their structure. Our tools will be antibodies, fluorescently-labelled proteins and high resolution microscopes. These include an electron microscope, and microscopes that can produce optical sections and in turn a 3D image. One of these is the confocal laser scanning microscope; the other involves removal of out-of-focus light from images using deconvolution software to achieve the same goal. We will detect different centromere proteins with different fluorochromes for fluorescence microscopes and different sizes of gold particles for the electron microscope. Using these microscopes we have already been able to find out where one of our neocentromeres is located within the nucleus. We have also started to look at centromeres with the electron microscope.Read moreRead less
Transcription At The Centromere: Roles In Formation, Maintenance And Function
Funder
National Health and Medical Research Council
Funding Amount
$549,092.00
Summary
Every human has 46 chromosomes. Chromosomes are structures that carry genes in all our cells. The centromere is an essential component of a chromosome which governs the process of cell division and separation of replicated chromosomes. Defects in centromere function cause abnormalities in cell division that in turn cause a variety of genetic diseases including cancer. We propose to investigate the role that transcription at the centromere plays in determining correct centromere function.
The Role Of Centromere Defects In Cancer Formation And Progression
Funder
National Health and Medical Research Council
Funding Amount
$601,386.00
Summary
When cells divide, their DNA must be copied and distributed faultlessly into the new cells. Defects in the factors that control this process will result in serious health problems including cancer. The objective of this project is to identify what these factors are and study how they contribute to cancer. Results gained from this project are expected to significantly increase our understanding of how cancer cells control the replication of their DNA and therefore their own fate.
Mechanisms By Which Chromatin Modulates Gene Expression.
Funder
National Health and Medical Research Council
Funding Amount
$267,750.00
Summary
Gene expression in a cell occurs in the nucleus where genes are stored. In the nucleus, DNA is not in a free form but is covered with an equivalent weight of protein to form a structure known as chromatin. Chromatin is a periodic structure made up of repeating, regularly spaced subunits, the subunit being the nucleosome. A nucleosome consists of a group of proteins (histones) wrapped around with DNA. A nucleosome is both capable of blocking and activating gene expression. Therefore one important ....Gene expression in a cell occurs in the nucleus where genes are stored. In the nucleus, DNA is not in a free form but is covered with an equivalent weight of protein to form a structure known as chromatin. Chromatin is a periodic structure made up of repeating, regularly spaced subunits, the subunit being the nucleosome. A nucleosome consists of a group of proteins (histones) wrapped around with DNA. A nucleosome is both capable of blocking and activating gene expression. Therefore one important function of chromatin is to tightly regulate gene expression which is essential to allow an organism to develop properly. When gene expression is not accurately controlled by chromatin developmental defects or cancer can result from the production of incorrect proteins. To control correct gene expression, highly specific mechanisms must operate in the cell to remove, or modify, nucleosomes at certain genes at a precise time during development. One mechanism that we believe to be important is changing the make-up of a nucleosome. This can be achieved in the cell by the replacement of histones with different specialized forms of these histones (variants). We believe that these histone variants can specifically generate chromosomal domains which could in some cases expose or in other cases hide certain genes and thereby turn them on or off. Employing a new approach, we will study one of these histone variants to discover the role it plays in determining the type of chromosomal domain made and the role of this domain has in turning genes on or off at precise times in early development during the formation of different specialized cell types. This new information may define targets for the prevention of incorrect gene expression during cancer progression or abnormal development.Read moreRead less
A Universal Clinical Test For Gene Fusions In Blood Cancer
Funder
National Health and Medical Research Council
Funding Amount
$628,001.00
Summary
Mis-repair of broken chromosomes results in gene fusion and is a common feature of blood cancers. Current tests are only capable of detecting well-known gene fusions and are incapable of identifying new fusion events or fusion variations. We have developed a scientific technique, termed CaptureSeq, that can address these issues. We propose to use this technique as the foundation for a single clinical test for blood cancers, capable of detecting all possible fusion variations – known and unknown.
Genomic Signposts, High-resolution Sequencing And Novel Genes In Eye Disease
Funder
National Health and Medical Research Council
Funding Amount
$333,694.00
Summary
Blindness is a very distressing sensory loss. Hereditary eye disorders account for the vision impairment in at least one-third of people who are registered as blind. These disorders cause blindness from a young age and work productivity is significantly impaired. This project will identify novel genetic factors in blinding eye disorders. Identifying these genetic factors will lead to better early detection methods for people and improved treatments to prevent the blindness.