The Embryological And Molecular Basis Of Zic2 Involvement In Holoprosencephaly
Funder
National Health and Medical Research Council
Funding Amount
$624,145.00
Summary
The brain is the most complex organ in the human body and diseases or disorders of the brain can become evident at any stage of life. Generally such problems have profound consequnces for the affected individuals and their families. One of the most common problems of brain development that is evident either at birth or within the first years of life is called holoprosencephaly (HPE). This condition affects the midline of the brain and the face and can lead to delay in mental, motor and language ....The brain is the most complex organ in the human body and diseases or disorders of the brain can become evident at any stage of life. Generally such problems have profound consequnces for the affected individuals and their families. One of the most common problems of brain development that is evident either at birth or within the first years of life is called holoprosencephaly (HPE). This condition affects the midline of the brain and the face and can lead to delay in mental, motor and language development, seizures, and obvious facial abnormalities. In its most severe form only one eye develops in the middle of the face, a condition known as cyclopia and a large majority of the severely affected children will die late in gestation or at birth. This condition can be inherited, but because the genetic lesions that cause this problem affect different people differently, people can carry the causative genetic change(s) without knowing it. We need to identify and study the genetic lesions that contribute to this condition in order to begin to understand how we can stop these mutations affecting the developing foetus. Because it is difficult to study embryonic development in humans we have generated a mouse model of this condition. In the mouse model just one gene (called Zic2) is altered and embryos that have two copies of this alteration develop the most severe form of cyclopia and die in the second half of gestation. This means that the normal role of this gene is to stop us developing HPE. We will use this mouse model to see just when and how the Zic2 gene prevents HPE. In addition, we will look to see what other genes Zic2 interacts with by breeding mice that carry the mutation in Zic2 with mice that carry a mutation in a second gene that can also cause HPE. These experiments are very important because if we understand how Zic2 and other genes protect us from HPE we can begin to design strategies to decrease the risk of a child developing this condition.Read moreRead less
The Role Of The Mammalian Grainyhead-like Gene Family In Neural Tube Closure
Funder
National Health and Medical Research Council
Funding Amount
$569,541.00
Summary
Failure of the skin to close over the brain and spinal cord during human development results in the devastating congenital birth defects anencephaly and spina bifida, known collectively as the neural tube defects. These are the second most common congenital birth defects affecting 1:1000 pregnancies. Anencephaly is not compatible with life and affected babies die at birth. In contrast children with spina bifida survive, but suffer from limb paralysis, bowel and bladder dysfunction, learning diff ....Failure of the skin to close over the brain and spinal cord during human development results in the devastating congenital birth defects anencephaly and spina bifida, known collectively as the neural tube defects. These are the second most common congenital birth defects affecting 1:1000 pregnancies. Anencephaly is not compatible with life and affected babies die at birth. In contrast children with spina bifida survive, but suffer from limb paralysis, bowel and bladder dysfunction, learning difficulties and psycho-social disturbances. Our laboratories have identified a family of genes essential for the colsure of the neural tube in mammals. The aim of this proposal is to understand the mechanisms of action with a view to developing new therapeutics that mey be used preventatively in these conditions. We also hope that these studies may facilitate the development of a genetic test to screen couples at risk.Read moreRead less
Thalamic And Basal Forebrain Contributions To Auditory Cortical Reorganization Produced By Partial Hearing Loss
Funder
National Health and Medical Research Council
Funding Amount
$364,768.00
Summary
When part of the cochlea is damaged in adult animals, leading to a partial hearing loss, the auditory area of the cerebral cortex reorganizes itself, so that the area deprived of input by the peripheral lesion is not silent, but is occupied by expanded representations of adjacent frequencies. This reorganization has been observed in a number of species, including non-human primates, and it seems likely that it also occurs in humans with cochlear damage and hearing loss of this sort. If it does, ....When part of the cochlea is damaged in adult animals, leading to a partial hearing loss, the auditory area of the cerebral cortex reorganizes itself, so that the area deprived of input by the peripheral lesion is not silent, but is occupied by expanded representations of adjacent frequencies. This reorganization has been observed in a number of species, including non-human primates, and it seems likely that it also occurs in humans with cochlear damage and hearing loss of this sort. If it does, it would have important consequences for the way in which input from a hearing aid or cochlear prosthesis (bionic ear) is processed in the brain. This Project is designed to clarify the nature of the systems in the brain that contribute to this form of cortical plasticity, using an animal model. One aim is to determine whether the plasticity is intrinsic to the cortex or occurs in the pathways over which information is conveyed to the cortex. This will be assessed by determining whether such plasticity is also found in the auditory thalamus, the final subcortical auditory nucleus from which information is sent to the cortex. The second aim is to determine whether the occurrence of plasticity is controlled by modulatory influences from the basal part of the forebrain. Neurons in this area project to many parts of the cortex, and evidence from other sensory systems suggests that these projections exert a permissive function, allowing the cortex to reorganize when input is altered. This aim will be pursued by determining whether cortical reorganization occurs after hearing loss when this basal forebrain system is inactivated. The significance of these studies is that they will elucidate the way in which the brain reorganizes itself when it is confronted with altered input. This information is important for our understanding of normal auditory information processing mechanisms and of the way in which input from prosthetic devices is processed in the hearing-impaired.Read moreRead less
The Role Of The MYST Family Transcriptional Co-activator, Mof, In Embryonic Development
Funder
National Health and Medical Research Council
Funding Amount
$319,446.00
Summary
A major task in biology is to understand how the human genome directs the development of a single cell to form an entire individual. Clearly, a large part of this task is to understand how the expression of genes is regulated during embryonic development. Gene expression requires co-activator complexes. Co-activator complexes typically contain proteins which regulate the structure of chromatin (a complex of DNA and histones). However, the physiological function of most co-activators is entirely ....A major task in biology is to understand how the human genome directs the development of a single cell to form an entire individual. Clearly, a large part of this task is to understand how the expression of genes is regulated during embryonic development. Gene expression requires co-activator complexes. Co-activator complexes typically contain proteins which regulate the structure of chromatin (a complex of DNA and histones). However, the physiological function of most co-activators is entirely unclear. The aim of this project is to study the function of Mof during embryonic development. Mof is a co-activator that directly regulates chromatin structure by modifying histones. Mof is a member of the MYST family of co activators, which includes Moz and Qkf. We have recently shown that Moz and Qkf are essential for the haematopoietic stem cell population and the neural stem cell population, respectively. The purpose of this project is to produce a detailed analysis of the function of Mof in vivo and determine it's importance in regulating gene expression. All biological processes relay on accurate regulation of gene transcription and all diseases, whether they involve pathogens or cell intrinsic pathological changes, such as cancer, lead to changes in gene expression. Regulation of chromatin structure has been identified as a major mechanism of transcriptional regulation in health and disease. However, our understanding of the precise molecular mechanisms regulating chromatin structure in vivo are very limited. This work will fully investigate the role of an important co-activator in vivo including a mechanistic analysis. This will increase understanding of how gene expression is regulated and, ultimately, this knowledge will find wide application in the development of new treatment paradigms.Read moreRead less
The Role Of The MYST Family Lysine Acetyltransferase, Hbo1, In Development And In The Adult
Funder
National Health and Medical Research Council
Funding Amount
$403,368.00
Summary
This project will produce a detailed analysis of the function of Hbo1, a transcription factor, and determine its importance in regulating gene expression. All biological processes rely on accurate regulation of gene transcription and all diseases lead to changes in gene expression. This work will increase understanding of how gene expression is regulated and, ultimately, this knowledge will find wide application in the development of new treatment paradigms.
Noradrenaline Transporter Dysfunction In Neural Circulatory Disorders: Clinical, Molecular And Therapeutic Implications
Funder
National Health and Medical Research Council
Funding Amount
$510,870.00
Summary
We will investigate the clinical relevance of noradrenaline transporter (NET) dysfunction and its molecular and genetic regulation in (1) essential hypertension, (2) postural tachycardia syndrome where the heart rate increases abnormally when the patient assumes an upright position and (3) syncope where subjects experience recurrent blackouts. In a therapeutic approach, we will explore whether NET inhibition can reduce the number of episodes and alleviate the symptoms associated with syncope.