Over the last 8 years, we identified and characterized patients with naturally occurring mutations in the orphan nuclear receptors, DAX1 and SF1, and demonstrated that DAX1 acts in part by inhibiting SF1- mediated transcription. Using targeted mutagenesis, we developed a murine Dax1 knockout (KO) model and identified roles for Dax1 in gonadal determination, testis development, and adult testis function. In this grant, we propose to extend these studies, which have provided unexpected insight into mechanisms of gonadal development. We propose 3 inter-related aims that focus on Dax1 structure and function as a transcriptional repressor, identify genetic pathways regulated by Dax1, and develop animal models to unravel the interplay of Dax1 with other genes involved in testis development and function. Specifically, in Aim 1 we will identify molecular partners that mediate DAX1 transcriptional repression. Naturally occurring DAX1 mutations will be identified and characterized to elucidate key structural domains required for DAX1 function in vivo. Candidate proteins identified in a yeast two-hybrid screen of an embryonic gonadal library will be further characterized. The goal of Aim 2 is to identify the genetic pathways regulated by Dax1 using microarray analyses of genes expressed in wild type versus Dax1-deficient embryonic gonads at 12 dpc, a timepoint when Dax1 expression diverges in males and females.
Aim 3 is designed to explore the interaction of Dax1 with other genetic pathways in vivo. Using mice that lack Dax1, we will explore the gonadal phenotypes of mice with selective rescue of Dax1 in various cell types. In addition, Dax1-deficient mice will be crossed to other strains with alterations in genetic pathways proposed to intersect with Dax1 (e.g., Sf1, Sry, Ptc). Success in these aims should provide a critical link between DAX1 and transcriptional repression pathways that link a variety of other transcription factors involved in gonadal development.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
1R01HD044801-01
Application #
6675743
Study Section
Reproductive Biology Study Section (REB)
Program Officer
Taymans, Susan
Project Start
2003-09-11
Project End
2008-06-30
Budget Start
2003-09-11
Budget End
2004-06-30
Support Year
1
Fiscal Year
2003
Total Cost
$313,641
Indirect Cost
Name
Northwestern University at Chicago
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
005436803
City
Chicago
State
IL
Country
United States
Zip Code
60611
Jadhav, Unmesh; Jameson, J Larry (2011) Steroidogenic factor-1 (SF-1)-driven differentiation of murine embryonic stem (ES) cells into a gonadal lineage. Endocrinology 152:2870-82
Jadhav, Unmesh; Harris, Rebecca M; Jameson, J Larry (2011) Hypogonadotropic hypogonadism in subjects with DAX1 mutations. Mol Cell Endocrinol 346:65-73
Lin, Lin; Philibert, Pascal; Ferraz-de-Souza, Bruno et al. (2007) Heterozygous missense mutations in steroidogenic factor 1 (SF1/Ad4BP, NR5A1) are associated with 46,XY disorders of sex development with normal adrenal function. J Clin Endocrinol Metab 92:991-9
Park, Susan Y; Tong, Minghan; Jameson, J Larry (2007) Distinct roles for steroidogenic factor 1 and desert hedgehog pathways in fetal and adult Leydig cell development. Endocrinology 148:3704-10
Verrijn Stuart, A A; Ozisik, G; de Vroede, M A et al. (2007) An amino-terminal DAX1 (NROB1) missense mutation associated with isolated mineralocorticoid deficiency. J Clin Endocrinol Metab 92:755-61
Lin, Lin; Gu, Wen-Xia; Ozisik, Gokhan et al. (2006) Analysis of DAX1 (NR0B1) and steroidogenic factor-1 (NR5A1) in children and adults with primary adrenal failure: ten years' experience. J Clin Endocrinol Metab 91:3048-54
Tan, Tiong Yang; Jameson, J Larry; Campbell, Peter Ellis et al. (2006) Two sisters with IMAGe syndrome: cytomegalic adrenal histopathology, support for autosomal recessive inheritance and literature review. Am J Med Genet A 140:1778-84
Bhangoo, Amrit; Gu, Wen-Xia; Pavlakis, Steven et al. (2005) Phenotypic features associated with mutations in steroidogenic acute regulatory protein. J Clin Endocrinol Metab 90:6303-9
Park, Susan Y; Jameson, J Larry (2005) Minireview: transcriptional regulation of gonadal development and differentiation. Endocrinology 146:1035-42
Park, Susan Y; Meeks, Joshua J; Raverot, Gerald et al. (2005) Nuclear receptors Sf1 and Dax1 function cooperatively to mediate somatic cell differentiation during testis development. Development 132:2415-23

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