Impact Of The Extraembryonic Tissues On Early Embryonic Development: Genetic Basis Of Abnormal Body Plan
Funder
National Health and Medical Research Council
Funding Amount
$316,326.00
Summary
An important milestone of early development is the attachment (or implantation) of the embryo to the wall of the womb through the action of a specialized population of cells known as the trophoblasts. The early conceptus comprises not only cells that make up the embryo but also those (called extraembryonic cells) that later forms the placenta, and the membranes that wrap around the developing fetus. The placenta and the membranes are indispensable for the normal fetal growth by providing the eff ....An important milestone of early development is the attachment (or implantation) of the embryo to the wall of the womb through the action of a specialized population of cells known as the trophoblasts. The early conceptus comprises not only cells that make up the embryo but also those (called extraembryonic cells) that later forms the placenta, and the membranes that wrap around the developing fetus. The placenta and the membranes are indispensable for the normal fetal growth by providing the effective nourishment and protection for the developing fetus. Recent studies in the mouse have revealed that normal development of the recently implanted conceptus depends on the reciprocal interaction of the embryonic and extraembryonic cells. Abnormal embryo may form if the non-embryonic cells do not differentiate normally, as seen in the situation when an X-chromosome is lost from the female embryo (as in 45X0 Turner syndrome) and in early conceptus that carries a gene mutation that affects the production of growth factors by the extraembryonic cells. Functional deficiency of the extraembryonic cells might be a cause for early pregnancy loss where the conceptus has successfully implanted but the embryo fails to form. The remarkable conservation of the molecular mechanism that controls mammalian development allows us to use the mouse embryo as a genetic model for human development. The proposed project is designed to examine in a laboratory mouse model the molecular and cellular factors that regulate the activity of the extraembryonic cells. Specifically, we focus on a gene known as Sox17, which may be involved with the differentiation of the extraembryonic cells. We will study the impact of the mutation of this gene on the development of the early embryo to test the hypothesis that the extraembryonic cells may fulfill an important function in ensuring normal embryo formation, in addition to the other roles of nourishment and mechanical protection of the fetus.Read moreRead less
The Role Of Crim1, A Novel TGFb Superfamily Modulator, In Early Vertebrate Patterning, Vascular And Renal Development.
Funder
National Health and Medical Research Council
Funding Amount
$501,300.00
Summary
The transforming growth factor (TGF) beta superfamily is a large group of secreted growth factors who play many different roles in normal development of tissues such as the brain, skeleton, heart, kidney, eyes, teeth and limbs. One of the groups within the superfamily, the bone morphogenetic proteins (BMPs), are being used in clinical trials to assist in regrowing bones after fracture. These molecules are also of interest for clinical reasons as growth factors within this family can also be dele ....The transforming growth factor (TGF) beta superfamily is a large group of secreted growth factors who play many different roles in normal development of tissues such as the brain, skeleton, heart, kidney, eyes, teeth and limbs. One of the groups within the superfamily, the bone morphogenetic proteins (BMPs), are being used in clinical trials to assist in regrowing bones after fracture. These molecules are also of interest for clinical reasons as growth factors within this family can also be deleterious, with their overexpression leading to conditions such as renal fibrosis and cataract. The activity of these growth factors is regulated by many other proteins, including protein antagonists which bind and inactivate them. It is therefore possible that by understanding these antagonists, we can find new ways of altering TGF beta superfamily activity. We have previously identified a novel protein, Crim1, which we have now shown can bind to TGF superfamily members and can reduce their secretion. We believe that Crim1 plays a role in the patterning of the central nervous system, the development of the blood vessels and the kidneys by regulating the TGFbeta superfamily. In this grant we will be investigating what the effect of disruption to Crim1 is on these organ systems and working out which members of the TGFbeta superfamily it is affecting to cause these effects. To do this, we will knock out the gene in zebrafish and characterise the defects found in a mouse line in which the gene has been disrupted. This may be important in developing new ways of activating or inactiviating these growth factors in a number of clinical conditions.Read moreRead less
Head Development: Genetic Determinants And Tissue Potency
Funder
National Health and Medical Research Council
Funding Amount
$947,116.00
Summary
Congenital malformations involving major defects of brain (anencephalus and related anomalies) and facial structures (ear, face and neck) are encountered in 3.4 and 1.4 per 10000 births respectively (Congenital Malformations Australia 1981-1996, National Perinatal Statistics Unit) and they constitute a substantial clinical burden. It is believed that these major structural defects usually result from abnormal development in the first trimester, which coincides with the time frame for the formati ....Congenital malformations involving major defects of brain (anencephalus and related anomalies) and facial structures (ear, face and neck) are encountered in 3.4 and 1.4 per 10000 births respectively (Congenital Malformations Australia 1981-1996, National Perinatal Statistics Unit) and they constitute a substantial clinical burden. It is believed that these major structural defects usually result from abnormal development in the first trimester, which coincides with the time frame for the formation of the basic components of the embryonic head in the mouse. Knowledge of the formation of the head in the mouse model is therefore relevant to the understanding of related developmental processes in early human development. This project which involves the application of sophisticated embryological and molecular analyses on mouse embryos generated by transgenesis and genetic manipulation provides a detailed studies of craniofacial morphogenesis in a mammalian model for early human development. The micro-manipulation procedures, embryo culture, fluorescence microscopy and the in situ hybridization are routinely performed in our laboratory, and most of the mouse lines are well established in my laboratory. Experiments proposed for this project that focus on the embryological and molecular analysis of normal and mutant embryos should discover new information on the cellular and molecular mechanisms that regulate head development. The knowledge will also offer insight into the pathogenesis of similar craniofacial malformations in other mutant embryos.Read moreRead less
A role for Cited2, Transforming Growth Factor-beta and matrix metaloproteinases in trophoblast invasion and placenta formation. The placenta is essential for the growth and development of the fetus, and if it fails to form correctly during pregnancy, it can have dramatic effects that can result death in utero, or adult onset diseases. Our research aims to understand how one protein functions in placenta formation. We will also investigate how this protein works at the molecular level in a proces ....A role for Cited2, Transforming Growth Factor-beta and matrix metaloproteinases in trophoblast invasion and placenta formation. The placenta is essential for the growth and development of the fetus, and if it fails to form correctly during pregnancy, it can have dramatic effects that can result death in utero, or adult onset diseases. Our research aims to understand how one protein functions in placenta formation. We will also investigate how this protein works at the molecular level in a process that enables single cells to respond to molecules sent from a distance by other cells (TGF-beta signalling). This process is also very important for a host of other biological processes relevant to human health, including cancer.Read moreRead less