Much of our current knowledge on development of external genitalia (ExG), the penis and clitoris, comes from 20 &70 year-old studies (1); but with significant developments in contemporary imaging and new mouse models, we have new data. The overall goal of this project is to prove the hypothesis that penile and clitoral development is estrogen- (and androgen-) dependent and, to show that the administration of exogenous endocrine disrupting chemicals that alter the balance between estrogen and and ....Much of our current knowledge on development of external genitalia (ExG), the penis and clitoris, comes from 20 &70 year-old studies (1); but with significant developments in contemporary imaging and new mouse models, we have new data. The overall goal of this project is to prove the hypothesis that penile and clitoral development is estrogen- (and androgen-) dependent and, to show that the administration of exogenous endocrine disrupting chemicals that alter the balance between estrogen and androgen will disrupt ExG development.Read moreRead less
Cohesin: Role In Germ Cell Chromosomal Segregation
Funder
National Health and Medical Research Council
Funding Amount
$435,526.00
Summary
At least 10 to 25% of all human fetuses have the wrong number of chromosomes (aneuploidy). Most of these abormal fetuses perish in utero, making it the leading known cause of early pregnancy loss. Aneuploidy is the leading genetic cause of developmental disabilities and mental retardation. Abundant evidence suggests that most of these chromosome abnormalities originate during unequal partitioning of genetic material (chromosomes) in eggs and sperm. The proposed project focuses on two related gen ....At least 10 to 25% of all human fetuses have the wrong number of chromosomes (aneuploidy). Most of these abormal fetuses perish in utero, making it the leading known cause of early pregnancy loss. Aneuploidy is the leading genetic cause of developmental disabilities and mental retardation. Abundant evidence suggests that most of these chromosome abnormalities originate during unequal partitioning of genetic material (chromosomes) in eggs and sperm. The proposed project focuses on two related genes, called Rec8 and Rad21, which we recently discovered in humans and mice. Due to that these genes are essential for chromosome separation in other species and they exists in species as diverse as yeast and humans, they may be responsible for accurate separation of chromosomes in germ cells in mammals. In this proposal, we will determine the role(s) of these molecules in controlling proper chromosome segregation by loss-of-function studies in genetically engineered mice lacking Rec8 and Rad21 genes. By analyzing the chromosomal abnormalities of the cells from these animals, we will gain critical information about the nature of chromosome partitioning disorders in humans.Read moreRead less
Role Of The Anaphase-Promoting Complex Activator Cdh1 In Oocyte Maturation And Meiotic Aneuploidy
Funder
National Health and Medical Research Council
Funding Amount
$526,878.00
Summary
Eggs containing an incorrect number of chromosomes are described as aneuploid. This project sets out to examine the molecular causes of aneuploidy and why it increases with female age. We focus on the protective role of the protein Cdh1 in this process. The outcome would be to better understand the origins of aneuploidy so as to find methods of decreasing it as women age. This is highly significant given aneuploidy is the leading cause of early embryo loss and produces Down Syndrome babies.
A New Model Of Asthenospermia And A Candidate Gene For Multiple Ciliopathies
Funder
National Health and Medical Research Council
Funding Amount
$629,039.00
Summary
Though the analysis of a unique mouse strain (Mot1) we have identified a previously unknown cause of male infertility and lung disease. We hypothesis that the Mot1 line is a model of human primary cilia dyskinesia and that the Mot1 protein is involved in cilia function. Within this project we will define the consequences of a loss of Mot1 protein function, we will define its binding partners and we will screen for mutations in the corresponding human gene.
Hypospadias is one of the most common developmental defects in humans, yet over two thirds of the cases cannot be explained. Our recent studies using marsupials show that this process is mediated by 5-alpha-androstanediol, a hormone with previously undetermined physiological function. This study will provide novel data on the interactions of the genes and hormones that will inform our understanding of this common developmental defect of male development
Disorders of sexual development are among the most common form of birth defects in humans (1 in 4,000 births) because failure of the gonads to develop does not affect the viability of the individual. Such disorders can have profound psychological and medical consequences upon the individual, family, and society. Some intersexual conditions are the result of inappropriate exposure to hormones during fetal life, and others are due to spontaneous or inherited gene mutation. About 5-10% of ovarian c ....Disorders of sexual development are among the most common form of birth defects in humans (1 in 4,000 births) because failure of the gonads to develop does not affect the viability of the individual. Such disorders can have profound psychological and medical consequences upon the individual, family, and society. Some intersexual conditions are the result of inappropriate exposure to hormones during fetal life, and others are due to spontaneous or inherited gene mutation. About 5-10% of ovarian cancer cases, that affect 1 in 8000 Australian women, are due to the inheritance of a faulty gene. An understanding of the way gene expression and hence tissue differentiation is altered after sex reversal will inform us about the causes and consequences of normal and abnormal sexual development, gonadal malignancies and infertility. The gonad is unusual in that two completely different organs can arise from an essentially identical primordium, so that errors in development lead to intersexual phenotypes. We will use our new experimental animal model to clarify these processes.Read moreRead less
Impairment of virilisation is one of the most common developmental defects in humans, yet over half the cases cannot be explained by our current knowledge. Studies of these processes is hindered because in most mammals virilisation occurs in the early fetus. Our recent studies using marsupials, where virilisation occurs after birth show that this process is mediated by 5-alpha-androstanediol, a hormone with previously undetermined physiological function. We will conduct experiments using tammar ....Impairment of virilisation is one of the most common developmental defects in humans, yet over half the cases cannot be explained by our current knowledge. Studies of these processes is hindered because in most mammals virilisation occurs in the early fetus. Our recent studies using marsupials, where virilisation occurs after birth show that this process is mediated by 5-alpha-androstanediol, a hormone with previously undetermined physiological function. We will conduct experiments using tammar wallabies and rabbits, to test 3 hypotheses about 5-alpha-androstanediol and specific enzymes in the developing reproductive tissues that either convert this hormone to active and inactive forms. The results of these experiments will direct testing for corresponding gene mutations in our collection of over 200 specimens from patients with defects of virilisation (pseudohemaphroditism) whose causes are still unknown. It is our expectation that the findings in these studies will provide insight not only into the pathways by which testicular hormones masculinize the developing male, but will also explain instances of male pseudohemaphroditism of unknown aetiology in humans.Read moreRead less
Follicle-stimulating hormone (FSH) is vital for egg development, female fertility and health, and is widely used in assisted reproduction technology. But high levels of FSH are associated with premature infertility and menopause, and may lead to diseases like ovarian cancer. Understanding the biological pathways activated by elevated FSH may lead to new treatments for infertility and ovarian diseases (eg. cancer), as well as advancing new strategies for contraception.
New Models For The Onset Of Virilisation In The Developing Male
Funder
National Health and Medical Research Council
Funding Amount
$405,750.00
Summary
Impairment of virilisation is one of the most common developmental defects in humans, yet over half the cases cannot be explained by our current knowledge. Studies of these processes are hindered because in most mammals virilisation occurs in utero, in the early fetus. Our recent studies using marsupials, where virilisation occurs after birth show that this process is mediated by 5-alpha-androstanediol, a hormone with previously undetermined physiological function. We will conduct experiments us ....Impairment of virilisation is one of the most common developmental defects in humans, yet over half the cases cannot be explained by our current knowledge. Studies of these processes are hindered because in most mammals virilisation occurs in utero, in the early fetus. Our recent studies using marsupials, where virilisation occurs after birth show that this process is mediated by 5-alpha-androstanediol, a hormone with previously undetermined physiological function. We will conduct experiments using tammar wallabies, to test hypotheses that explain why different male tissues - such as the reproductive ducts, prostate and penis - start to differentiate at widely different times. We will investigate pathways of androgen formation and the activation and inactivation of hormones in the target organs, and the role of hormone binding proteins. We will also investigate the role of growth factors that may mediate growth of the penis during early development. The results of these experiments will direct funding in subsequent years to test for corresponding gene mutations in our collection of over 200 specimens from patients with defects of virilization (pseudohermaphroditism) whose causes are still unknown. It is our expectation that the findings in these studies will provide insight not only into the pathways by which testicular hormones masculinize the developing male, but will also explain instances of male pseudohermaphroditism of unknown aetiology in humans.Read moreRead less
Discriminating The Roles Of Inhibin A And B In Reproductive Systems
Funder
National Health and Medical Research Council
Funding Amount
$312,576.00
Summary
Inhibin A and B are essential for the regulation of fertility based on their dual inhibitory actions on follicle stimulating hormone secretion by the pituitary and egg and sperm production in the gonads. An understanding of the mechanisms involved in inhibin A and B actions will: (1) identify novel biomarkers for the diagnosis of reproductive disorders (2) enhance the management of reproductive disorders (3) identify targets for the development of therapeutic means of modulating fertility