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
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
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
Understanding Immune Tolerance In Pregnancy To Discover A New Intervention For The Treatment Of Pre-eclampsia
Funder
National Health and Medical Research Council
Funding Amount
$492,202.00
Summary
Pre-eclampsia is a common complication of pregnancy. Women who develop pre-eclampsia experience high blood pressure, swelling and lose protein in the urine. There is no treatment for pre-eclampsia other than delivery of the baby. Pre-eclampsia has risks for the mother and the baby. This research will discover whether generalised inflammation in the mother is a cause of pre-eclampsia and will evaluate the role of a novel treatment for its potential to prevent this life threatening condition.
Comparison Of Pregnancy Outcomes Following Transferring One Or Two Embryos In A Selected Group Of Infertility Patients.
Funder
National Health and Medical Research Council
Funding Amount
$120,302.00
Summary
Assisted reproductive technology (ART) deals with issues of fundamental importance to individuals involved, and society as a whole. Despite major advances, ART continues to be very costly in many regards. A major reason for this is the relatively low rate of pregnancy, which averages 25% per procedure. The common response to the problem of low pregnancy rates is to return several embryos to uterus. A dilemma associated with this strategy is the high risk of multiple pregnancy, which is associate ....Assisted reproductive technology (ART) deals with issues of fundamental importance to individuals involved, and society as a whole. Despite major advances, ART continues to be very costly in many regards. A major reason for this is the relatively low rate of pregnancy, which averages 25% per procedure. The common response to the problem of low pregnancy rates is to return several embryos to uterus. A dilemma associated with this strategy is the high risk of multiple pregnancy, which is associated with adverse consequences for mother and fetus(es). Compared to singleton births; fetal, neonatal, and perinatal mortality rates are 3-6 times higher in twins, and 5-15 times higher in multiple births of a higher order. Cerebral palsy rates among survivors are six times higher in twins and twenty times higher in triplets. The increase in the incidence of adverse outcomes related to multiple pregnancy has been well documented in ART. We propose a randomised controlled study to assess single embryo transfer (SET) compared to double embryo transfer (DET). Infertility women with a high risk of multiple pregnancy will be randomly allocated to receive one or two embryos, which is the usual treatment at present. We shall then examine the rates of single and multiple pregnancies, and the success of those pregnancies in this group of patients. Potential benefits to the community from this project are very substantial, as it has the capacity to substantially reduce the number of multiple births. Patients will also benefit by having more accurate information with which to make an informed choice during treatment.Read moreRead less
Implantation of an embryo into the uterus & development of a functional placenta are critical to initiate & continue a pregnancy. Implantation failure causes infertility and is a major bottle-neck in IVF. Placental insufficiency leads to pregnancy loss, under-developed fetuses & a life-threatening pregnancy-specific disease preeclampsia. This application will investigate how a woman’s uterus works for implantation and placental development, how to increase IVF success and diagnose & potentially ....Implantation of an embryo into the uterus & development of a functional placenta are critical to initiate & continue a pregnancy. Implantation failure causes infertility and is a major bottle-neck in IVF. Placental insufficiency leads to pregnancy loss, under-developed fetuses & a life-threatening pregnancy-specific disease preeclampsia. This application will investigate how a woman’s uterus works for implantation and placental development, how to increase IVF success and diagnose & potentially treat preeclampsia.Read moreRead less
Metabolic And Molecular Determinants Of Embryo Viability
Funder
National Health and Medical Research Council
Funding Amount
$551,321.00
Summary
We know that our health as adults is influenced by the lifestyle of our mothers during pregnancy. In particular, increased risk of adult-onset diseases such as diabetes and cardiovascular disease occurs when small and lean infants at birth are raised in conditions where nutrient intake is not restricted and obesity occurs. This concept of fetal programming is now widely accepted. Our laboratory is leading research in a new concept, that of embryonic programming. We have extensive animal data dem ....We know that our health as adults is influenced by the lifestyle of our mothers during pregnancy. In particular, increased risk of adult-onset diseases such as diabetes and cardiovascular disease occurs when small and lean infants at birth are raised in conditions where nutrient intake is not restricted and obesity occurs. This concept of fetal programming is now widely accepted. Our laboratory is leading research in a new concept, that of embryonic programming. We have extensive animal data demonstrating that exposure of embryos to physiological perturbations alters fetal development, similarly to that occurring in nutrient restriction during pregnancy. Furthermore, there is data from IVF-derived children that their birth-weight is lower than expected, possibly due to the conditions used for conception in the laboratory. How does the response by eggs and embryos, at the time of conception, affect subsequent development? There has been some focus on changes to DNA that are not related to mutations, but structural changes in the DNA that alters gene expression. We call this epigenetics and epigenetic changes are found in embryos, including human embryos following IVF. However, no one knows how such epigenetic changes occur as a result of this stress response by the egg or embryo. Our proposal is to determine the mechanism of how epigenetic alterations take place in eggs and embryos. Our theory is that the mitochondria, the energy producing packages within all cells, are sending signals to the embryo's nucleus. When the egg or embryo finds itself in adverse conditions, the signals change as a result of changes in the energy balance. This in turn changes the activity of enzymes in the nucleus that regulates DNA structure. If we can prove that this relationship occurs, then we can assess these changes in human embryos that are excess to a patient's requirements and learn if programming takes place in human embryos.Read moreRead less
I am a reproductive biologist whose research is focussed around understanding how the early events of conception and embryo development are controlled. Critical aspects of my research are to determine the consequences to pregnancy and adult health if the
I am a reproductive biologist - reproductive immunologist investigating the role of the female immune response and its cellular and molecular agents in establishing pregnancy. My research spans basic science and clinical and commercial transfer, and aims to improve our understanding of the factors determining optimal reproductive health in women leading to better treatments for infertility and pathologies of pregnancy, and the best possible health outcomes for babies and children.