Gonadotropin Inhibitory Hormone As A Major Regulator Of Reproduction In Mammals
Funder
National Health and Medical Research Council
Funding Amount
$623,378.00
Summary
Reproduction is controlled by the brain and it has been well established that gonadotropin releasing hormone (GnRH) is the primary stimulatory factor. GnRH stimulates the pituitary gland to produce and secrete hormones that, in turn, stimulate the ovaries and testes. It is becoming clear that the brain also produces an inhibitory factor and this project aims to establish that it (gonadotropin inhibitory hormone; GnIH) is functional in mammals.
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
Epithelial-trophoblast Interactions In Human Embryo Implantation: Role For Interleukin 11 And Leukemia Inhibitory Factor
Funder
National Health and Medical Research Council
Funding Amount
$495,667.00
Summary
Infertility, spontaneous abortion and pre-eclampsia are major clinical problems. Female infertility is frequently due to implantation failure and many IVF embryos fail to implant. Appropriate development of the placenta is critical to the outcome of pregnancy and inadequate placentation can result in spontaneous abortion. However, if the pregnancy continues with a poorly developed placenta, the mother is likely to develop pre-eclampsia with subsequent major adverse outcomes for both mother and b ....Infertility, spontaneous abortion and pre-eclampsia are major clinical problems. Female infertility is frequently due to implantation failure and many IVF embryos fail to implant. Appropriate development of the placenta is critical to the outcome of pregnancy and inadequate placentation can result in spontaneous abortion. However, if the pregnancy continues with a poorly developed placenta, the mother is likely to develop pre-eclampsia with subsequent major adverse outcomes for both mother and baby. Pre-clampsia is the most common cause of low birth weight infants and also of maternal death. Low birth weight, which is commonly an outcome of a pregnancy with pre-eclampsia, correlates with disorders later in life (including hypertension, diabetes, coronary heart disease and obesity). Interleukin (IL)-11 and leukemia inhibitory factor (LIF) are among very few molecules known to be critical for embryo implantation in the mouse. Their roles in human infertility are not well understood, although there is evidence that decreased LIF is associated with implantation failure in women. The distribution of these molecules within the uterus and placenta in primates suggests they have important roles in preparing the uterine lining for implantation and for development of a placenta in women. This project will examine how IL-11 and LIF that are locally produced at implantation sites affect the human uterus and the formation of the placenta. There is still no means of readily diagnosing endometrial infertility in women or of establishing whether the placenta is developing adequately. These studies will provide new critical information regarding the roles of these two molecules and their potential usefulness as targets for much- needed diagnostic and therapeutic tools for infertility and major diseases associated with pregnancy. Application of such new tests will produce lifelong benefits to the health of both the mother and child.Read moreRead less
The Function Of Gametogenenin In Male Fertility And Embryogenesis
Funder
National Health and Medical Research Council
Funding Amount
$537,579.00
Summary
We have identified gametogenetin as novel protein involved in sperm production and in the very earliest stages of embryo survival. It is found within the sperm tail where it binds to cysteine-rich secretory protein 2. The aim of this project is to further refine the biochemistry of GGN using a combination of binding studies, expression analyses and the characterization of two unique mouse models. This project has direct relevance to the causes of human infertility and contraceptive development.
Kisspeptin And Its Receptor Mastermind Reproduction
Funder
National Health and Medical Research Council
Funding Amount
$601,979.00
Summary
Reproduction is controlled by the brain and gonadotropin releasing hormone (GnRH) is the primary stimulatory factor. Finding critical regulators of GnRH has remained the most important goal for reproductive endocrinologists for over 30 years. The brain peptide hormone called kisspeptin and its receptor Kiss1R appear vital in the control of reproduction. This project will detail the role kisspeptin and Kiss1R play in controlling hormones from the brain that govern puberty and reproduction.
The Identification Of Male Meiosis Genes Using A New Mouse Line And Human Genome Scans For Gene Copy Number Variations
Funder
National Health and Medical Research Council
Funding Amount
$604,793.00
Summary
Infertility affects 1 in 25 Australian men and meiosis is a key process in male fertility, yet we know very little about the mechanisms that control it. We will use a new point mutant mouse model of meisois failure to identify a novel regulator of male fertility. Further, we hypothesize that changes in gene copy number will lead to meiosis arrest and infertility in some men. Such variations will be assessed through a whole genome scan of a unique set of infertile men.
The Structural Basis Of The Interaction Of Insulin-like Peptide 3, A Key Regulator Of Fertility, With Its Receptor.
Funder
National Health and Medical Research Council
Funding Amount
$555,693.00
Summary
The hormone, insulin-like peptide 3, has recently been shown to act directly on male and female germ cells to cause their maturation. It has considerable promise as a therapeutic agent for the regulation of fertility. Drugs based on the peptide may be used to assist in cases of infertility, and drugs that block its action have great potential as male and female contraceptives. Towards these goals, our project aims to understand how this peptide exerts its unique biological effects.
BH3-only Proteins Are Critical For The Developmentally Programmed Death Of Oocytes: Impact On Ooctye Quality And The Fertile Lifespan
Funder
National Health and Medical Research Council
Funding Amount
$273,537.00
Summary
The ability of women to have healthy children, and the age at which menopause occurs, are largely dependent on the number and quality of the eggs stored in their ovaries. For unknown reasons, around two-thirds of all eggs die very shortly after they are made. We are unraveling the genes involved in determining whether an egg will live or die, and are investigating the role of these genes as _quality control sentinels", responsible for ensuring that only the highest quality eggs are ovulated.
Proprotein Convertase 6: A Master Regulator For The Development Of Endometrial Receptivity And Embryo Implantation
Funder
National Health and Medical Research Council
Funding Amount
$424,846.00
Summary
Implantation of an embryo into the womb (uterus) is a key step for human development, without which the embryo will only be able to develop to a very early stage the blastocyst stage (about 8 days after fertilization). For successful implantation, the uterus has to prepare itself to be receptive; this preparation is crucial as an ill-prepared uterus will reject the embryo. Such implantation failure is a major cause of early pregnancy loss and female infertility; ~30% of pregnancies end in sponta ....Implantation of an embryo into the womb (uterus) is a key step for human development, without which the embryo will only be able to develop to a very early stage the blastocyst stage (about 8 days after fertilization). For successful implantation, the uterus has to prepare itself to be receptive; this preparation is crucial as an ill-prepared uterus will reject the embryo. Such implantation failure is a major cause of early pregnancy loss and female infertility; ~30% of pregnancies end in spontaneous abortion. How the uterus becomes receptive is not well understood. Our recent research has identified that proprotein convertase 6 (PC6), an important master switch responsible for activating other proteins, is tightly regulated in the uterus during its preparation for receptivity and critical for implantation. This project will examine how PC6 acts in the human uterus to make it receptive, by identifying the factors that PC6 controls and how this controlling works. We will use a cell culture model with cells isolated from human term placenta. In addition, there is no means of readily testing whether the uterus is receptive owing to the lack of reliable biomarkers. In this study we will determine whether PC6 (and those molecules controlled by PC6) are potential biomarkers for uterine receptivity. This will be achieved by examining uterine biopsies and uterine washings collected from proven fertile volunteers and patients of proven endometrial infertility. This study will greatly enhance our understanding of how a critical molecule, PC6, acts in the uterus for implantation. The results will provide new knowledge regarding uterine preparation for implantation. The study has considerable implication for developing much-needed diagnostic and therapeutic tools for uterine receptivity and infertility.Read moreRead less
Positional Candidate Targets For Multiple Ovulation Genes
Funder
National Health and Medical Research Council
Funding Amount
$272,036.00
Summary
The frequency of non-identical twins is associated with fertility in individuals and populations, although we know little about mechanisms for twinning or effects on fertility. The likelihood for giving birth to non-identical twins is influenced by genetic factors. The probability of a subsequent twin pregnancy is increased fourfold in mothers of twins and roughly doubled for women whose mother or sister has had non-identical twins. Understanding why some women are more likely to have twins will ....The frequency of non-identical twins is associated with fertility in individuals and populations, although we know little about mechanisms for twinning or effects on fertility. The likelihood for giving birth to non-identical twins is influenced by genetic factors. The probability of a subsequent twin pregnancy is increased fourfold in mothers of twins and roughly doubled for women whose mother or sister has had non-identical twins. Understanding why some women are more likely to have twins will help us find key pathways that control normal ovarian function and important factors that influence success in assisted reproduction. The aim of this project is to search for these genes in families with two sisters who have given birth to non-identical twins. Previous studies have identified one strong target region and two possible regions containing genes for increased twinning. We now have additional families and will examine each region in more detail. We will also look for genes within each region that could be responsible for variation in twin frequency.Read moreRead less