Constructing an embryo. This project investigates the cellular and molecular mechanisms underlying temporal and spatial organisation in the eutherian preimplantation embryo. It will examine: the relative roles of cell cycle and circadian clocks in developmental timing; the molecular mechanism by which intercellular adhesion patterns influence spatial organisation; the extent to which marsupials use similar timing and spatial localisation mechanisms to eutherians; the impact of in-vitro manipulat ....Constructing an embryo. This project investigates the cellular and molecular mechanisms underlying temporal and spatial organisation in the eutherian preimplantation embryo. It will examine: the relative roles of cell cycle and circadian clocks in developmental timing; the molecular mechanism by which intercellular adhesion patterns influence spatial organisation; the extent to which marsupials use similar timing and spatial localisation mechanisms to eutherians; the impact of in-vitro manipulations over the first 5 days of mouse pregnancy on embryonic temporal and spatial organisation.Read moreRead less
Role Of Tumour Suppressor Genes In Early Embryopathy
Funder
National Health and Medical Research Council
Funding Amount
$408,000.00
Summary
Assisted reproductive technologies (ART, such as IVF and related techniques) are successful treatments for most forms of infertility. Much of this is due to the high mortality of the resulting embryos. Typically, 45-80% of embryos produced by ART do not survive the first week. The high mortality of the early embryo seems to be a general feature of ART but its causes and effectors are incompletely defined. It has been established that this high mortality is largely due to a marked retardation in ....Assisted reproductive technologies (ART, such as IVF and related techniques) are successful treatments for most forms of infertility. Much of this is due to the high mortality of the resulting embryos. Typically, 45-80% of embryos produced by ART do not survive the first week. The high mortality of the early embryo seems to be a general feature of ART but its causes and effectors are incompletely defined. It has been established that this high mortality is largely due to a marked retardation in the rate of cell cycle progression by embryo cells, and commonly is associated with a form of cell 'suicide', known as apoptosis. In non-embryonic cells a group of genes known as the tumour suppressor genes (TSGs) are responsible for slowing cell-cycle progression and are commonly involved in inducing apoptosis following cell stress. The role of TSGs in the early embryo is not well studied. We have recently shown that the most important of the TSGs, P53, is normally kept at very low levels in the early embryo but that ART causes up-regulation of its expression. This upregulation is a major cause of the embryopathy associated with ART in an animal model but that genetic mutations that prevent P53 expression favours increased embryo development and viability. This project will examine whether ART also causes up-regulation other important TSGs and whether this occurs in human embryos. We will examine the hypothesis that ART increases the survival of embryos with mutations to the P53 gene (creating a postive genetic selection pressure in favour of these mutations); and which aspects of ART cause this positive selection. The project will demonstarte whether changes in the ART procedures have the potential to mitigate against selection of embryos bearing deletrious mutations.Read moreRead less
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
Roles Of TGFbeta Receptor TGFBR3 (Betaglycan) In Testis Development
Funder
National Health and Medical Research Council
Funding Amount
$332,660.00
Summary
Diseases of the reproductive tract are major health issues. At lease 1 in 100 live births display some sort of gonadal defects. Later in adulthood, one in six couples are affected by infertility, and cancers of the reproductive tract which result in a significant number of deaths each year. This project focuses on understanding the role of the transformation growth factor beta receptor3 (Tgfbr3) in the embryonic and neonatal testis and its impact on adult male reproductive capacities and health.
I am a reproductive biologist, studying how the environment, both in vivo and in vitro, interacts with oocytes and early embryos in determining both their short and long-term development, with specific interests in application to clinical infertility treatment.
The Mechanism Of Spermatid Differentiation - A Link To Tumour Suppression
Funder
National Health and Medical Research Council
Funding Amount
$506,425.00
Summary
To discover novel regulators of male fertility, we have screened libraries of mutant mice generated by a chemical mutagen. This project aims to define the function of the mutated gene identified in a male-specific infertile mutant mouse line. The mutated gene has been proposed to play a role in regulating cell death and suppress lung tumour formation. Our data may reveal novel options for male infertility treatment and for the development of male contraception and lung cancer biomarkers.
A Novel Procedure For Efficacious Gonadotrophin-free Infertility Treatment
Funder
National Health and Medical Research Council
Funding Amount
$436,328.00
Summary
Infertility is common and is associated with health risks and is expensive. Using laboratory animals, we have developed a unique procedure, which has comparable success rates to IVF but crucially, it eliminates the need for ovarian hormone therapy used in IVF. A clinical trial using this method has started in Brussels and in this project we will examine cells from that trial and from animals to investigate the underlying mechanisms to enable safe and rapid clinical implementation.
GM-CSF Regulation Of Preimplantation Embryo Development
Funder
National Health and Medical Research Council
Funding Amount
$481,320.00
Summary
Treatment of infertility using IVF technology has been enormously successful. However, there are major concerns regarding the high incidence of multiple pregnancies (caused by the transfer of more than one embryo) and the potential adverse health outcome of adults conceived from this technology. Multiple pregnancies place both mother and infant at enormous risks, with increased obstetrics care, prematurity, increased neonatal care and neurological disorders such as cerebral palsy. This can be ov ....Treatment of infertility using IVF technology has been enormously successful. However, there are major concerns regarding the high incidence of multiple pregnancies (caused by the transfer of more than one embryo) and the potential adverse health outcome of adults conceived from this technology. Multiple pregnancies place both mother and infant at enormous risks, with increased obstetrics care, prematurity, increased neonatal care and neurological disorders such as cerebral palsy. This can be overcome simply by the transfer of a single embryo. However, patient and clinical expectations are that single embryo transfer should be achieved with little to no reduction in pregnancy rate, and currently this is not possible because our methods for culturing embryos are inadequate. Studies in animals suggest that laboratory growth of mammalian embryos can lead to small-for-gestational age babies (even when the effect of multiple births is taken into consideration). This backed by recent studies which agree that babies born from IVF are smaller than expected. This might lead to health problems in later life, as smallness at birth is associated with higher risks of cardiovascular disease and diabetes, especially as age progresses beyond 40 years. However, the oldest IVF child is currently 23 years of age. Previously we have shown that a protein growth factor, called granulocyte-macrophage colony-stimulating factor (GM-CSF), found normally in the reproductive tract, has dramatic beneficial effects on human and mouse embryos grown in the laboratory. Furthermore, we have shown in mice that embryo exposure to GM-CSF alleviates the detrimental side effects of in vitro culture on foetal growth and body structure after birth. Our research is now focussed on understanding why this protein is beneficial to embryo growth and to test if we can increase pregnancy rates and produce normal healthy infants from the transfer of single embryos treated with GM-CSF.Read moreRead less