A Y CHROMOSOME MODEL FOR THE SEX DETERMINING FUNCTION OF THE HUMAN ATRX GENE
Funder
National Health and Medical Research Council
Funding Amount
$272,131.00
Summary
Human sex determination is controlled by a genetic pathway which culminates in the development of a testis or an ovary in the human embryo. At the head of this pathway is the master switch gene SRY on the Y chromosome, which controls a cascade of other genes critical for switching on testis development. Several other genes have been identified by clinical mutations which reverse sex of XY embryos. One sex reversing gene is ATRX on the human X chromosome. Mutation in ATRX causes XY embryos to dev ....Human sex determination is controlled by a genetic pathway which culminates in the development of a testis or an ovary in the human embryo. At the head of this pathway is the master switch gene SRY on the Y chromosome, which controls a cascade of other genes critical for switching on testis development. Several other genes have been identified by clinical mutations which reverse sex of XY embryos. One sex reversing gene is ATRX on the human X chromosome. Mutation in ATRX causes XY embryos to develop as females, as well as causing many unrelated disorders such as alpha-thalassemia. ATRX seems to be a transcription factor that controls the activity of other genes, but it is difficult to understand how it functions because it is active in all parts of the body and mutation has many different effects in humans. However, we recently discovered that in marsupial mammals that this gene has a copy on the Y chromosome (ATRY) as well as the X (ATRX). Remarkably, there is a division of labour between ATRY, which acts only in developing gonads, and ATRX, which is active everywhere else. This testis-specific ATRY gene may reveal how ATRX interacts with other genes to make a testis, without the complications of its action in other tissues. We will therefore clone and characterize ATRX-Y and its protein product to find out when and where it acts in the sex determining pathway. We will use very large cloned pieces of the marsupial genome to discover elements controlling the testis-specific expression, and we will identify the interactions of ATRY with other proteins. The testis determination pathway is a good model for the differentiation of other human organs. Our work on ATRY will show us how this class of transcription factors is activated in different tissues during development, and how it controls other genes. This will lead to a better understanding of the genetic control of human organogenesis and the effects of mutation on human development.Read moreRead less
Defects in sexual development in the human embryo result in some of the most common forms of birth defects, which have profound physiological and psychosexual ramifications for the afflicted individuals. A fuller understanding of the causes of these defects may lead to improved counseling and perhaps also therapeutic possibilities. This project is aimed at finding and studying the genes that control whether an embryo develops as a male or a female, and the genes that are responsible for proper d ....Defects in sexual development in the human embryo result in some of the most common forms of birth defects, which have profound physiological and psychosexual ramifications for the afflicted individuals. A fuller understanding of the causes of these defects may lead to improved counseling and perhaps also therapeutic possibilities. This project is aimed at finding and studying the genes that control whether an embryo develops as a male or a female, and the genes that are responsible for proper development of the gonads, organs that control an individual's sexual development. It is thought that a genetic chain of events is important for gonadal development, and we aim to find the missing links of that chain and to work out how they fit together.Read moreRead less
Functional Analysis Of Candidate Sex-determining And Gonadal Development Genes
Funder
National Health and Medical Research Council
Funding Amount
$503,500.00
Summary
This project is aimed at finding and studying the genes that control whether an embryo develops as a male or a female, and the genes that are responsible for proper development of the gonads, organs that control an individual's sexual development. It is thought that a genetic chain of events is important for gonadal development, and we aim to find the missing links of that chain and to work out how they fit together, as well as how genetic defects can lead to disorders of sexual development. Def ....This project is aimed at finding and studying the genes that control whether an embryo develops as a male or a female, and the genes that are responsible for proper development of the gonads, organs that control an individual's sexual development. It is thought that a genetic chain of events is important for gonadal development, and we aim to find the missing links of that chain and to work out how they fit together, as well as how genetic defects can lead to disorders of sexual development. Defects in sexual development in the human embryo not only result in some of the most common forms of birth defects but also have profound physiological and psychosexual ramifications for the afflicted individuals. A fuller understanding of the causes of these defects will lead to improved patient management.Read moreRead less
I am a geneticist determining the molecular mechanisms that underlie gonad (testis and ovary) development and dysgenesis in patients with disorders of sexual development.
Copy Number Analysis Of Patients With Gonadal Abnormalities Using High Density Microarrays And MLPA
Funder
National Health and Medical Research Council
Funding Amount
$311,187.00
Summary
Congenital conditions in which development of the gonads or anatomical sex is abnormal are surprisingly common. The underlying cause of these problems is most often the failure of genes responsible for proper development of testes or ovaries. Only a small proportion of patients can be explained by mutations in known gonad determining genes. We will analyse DNA from these patients on very high density microarrays to identify new genes that cause abnormalities in testis and ovary development.
Role Of Human SRY And SOX9 In Sex Determination And Disease.
Funder
National Health and Medical Research Council
Funding Amount
$308,820.00
Summary
The decision to develop as a male or female is controlled by a genetic pathway which culminates in the development of a testis or an ovary in the human embryo. The correct development of these reproductive organs depends on the coordinated activation of a network of genes by transcription factors. Analysis of patients with defective reproductive organs has shown that a number of these individuals have mutations in two transcription factor genes, SRY and SOX9. Mutations in SRY (Swyer syndrome) or ....The decision to develop as a male or female is controlled by a genetic pathway which culminates in the development of a testis or an ovary in the human embryo. The correct development of these reproductive organs depends on the coordinated activation of a network of genes by transcription factors. Analysis of patients with defective reproductive organs has shown that a number of these individuals have mutations in two transcription factor genes, SRY and SOX9. Mutations in SRY (Swyer syndrome) or SOX9 (autosomal sex reversal-campomelic dysplasia) cause the development of female reproductive structures in individuals with male chromosomes. Towards understanding how SRY and SOX9 work to determine sex, we have identified four proteins that interact with SRY and SOX9. Two of these proteins, called importin-beta and calmodulin have a role in transporting SRY and SOX9 into the cell nucleus. The other two proteins, called PC4 and HSP70, appear to be involved in co-operating with SRY and-or SOX9 to turn genes on. In the developing mouse testis, a large number of genes are expressed at the time immediately following the expression of SRY and SOX9. We will identify which of these 50 genes are being directly switched on or off by SRY and SOX9 during sex determination. These studies will identify how SRY and SOX9 direct normal testis formation and how mutations cause developmental defects. Also, by unravelling the testis formation pathway, we expect to identify new genes involved in sexual dysmorphology syndromes.Read moreRead less
Actin cytoskeleton regulation by E-cadherin and Src. This project examines a fundamental, novel mechanism of how cells work together in tissues. It will provide important new knowledge about how tissues become organized in health, and how organization might be disturbed in disease. It will build Australia's skill base in cutting-edge scientific research, and promote knowledge directed to the research priority area of Promoting and Maintaining Good Health.
How the Y Chromosome makes a male: Molecular genetic analysis of key sex-determining genes. Sex reversal and intersex syndromes are among the most common and highly stigmatized disorders affecting newborn babies. Our research will reveal how the Y chromosome regulates normal male development, identify the steps that go wrong in many male babies, and suggest ways to diagnose and deal with these conditions. It will also pave the way for biotechnological applications in the areas of stem cell techn ....How the Y Chromosome makes a male: Molecular genetic analysis of key sex-determining genes. Sex reversal and intersex syndromes are among the most common and highly stigmatized disorders affecting newborn babies. Our research will reveal how the Y chromosome regulates normal male development, identify the steps that go wrong in many male babies, and suggest ways to diagnose and deal with these conditions. It will also pave the way for biotechnological applications in the areas of stem cell technology, pest management, wildlife conservation and animal breeding.Read moreRead less