The sex determining gene (Sry) on the mouse Y chromosome encodes a protein with two major domains: an amino terminal HMG box and a carboxyl glutamine-rich (Q-rich) domain. The HMG box has been demonstrated to bind to DNA in a sequence-specific manner. The function for the Q-rich domain is unknown. It is primarily encoded by an in-frame insertion of a CAG repetitive sequence. Recently, using the farwestern blotting technique, we have demonstrated that this Sry Q-rich domain is a protein-binding domain and interacts specifically with 3 major proteins (Sips) present in adult testis and embryonic tissues. Further studies demonstrated that the Sips are preferentially expressed in somatic cells of the adult testis and early embryonic tissues and fetal gonads at the time of sex determination. We hypothesize that the Sips play a critical role(s) as co-factors of Sry in testis determination.
Three specific aims are proposed in this application to test this hypothesis. First, we will address the question regarding the importance of the HMG box and Q-rich domains in Sry function using transgenic mouse approaches. Chimeric Sry genes will be constructed to harbor various combinations of HMG box and Q-rich domain from different mouse strains that exhibit incompatibility among their Sry genes. They will be evaluated in terms of their ability to mediate testis determination in transgenic XX animals. We plan to determine whether the HMG box or the Q-rich domain is responsible for such incompatibility. Second, interactive cloning techniques, affinity chromatography and protein microsequencing will be used to isolate the cDNAs for the Sips. The interactive properties of their encoded proteins to the Sry Q-rich domain will be confirmed independently. Third, we will characterize the Sip genes in terms of their cDNA sequences, expression patterns, protein structures, interactive domain(s), chromosomal locations, and evolutionary conservation. We will investigate their probable polymorphisms among different musculus and domesticus strains. We hope to relate such polymorphisms to their compatibility in Sry interactions. Their functions are further delineated by gene knockout strategies. Understanding the mechanisms of sex determination in mouse may shed insights on those in humans, and eventually may lead to developments of clinical diagnosis and treatment of gonadal dysgenesis and infertility.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
Research Project (R01)
Project #
5R01HD038117-05
Application #
6699975
Study Section
Reproductive Biology Study Section (REB)
Program Officer
Taymans, Susan
Project Start
2000-06-01
Project End
2007-02-28
Budget Start
2004-03-01
Budget End
2007-02-28
Support Year
5
Fiscal Year
2004
Total Cost
$297,000
Indirect Cost
Name
Northern California Institute Research & Education
Department
Type
DUNS #
613338789
City
San Francisco
State
CA
Country
United States
Zip Code
94121
Li, Yunmin; Kido, Tatsuo; Garcia-Barcelo, Maria M et al. (2015) SRY interference of normal regulation of the RET gene suggests a potential role of the Y-chromosome gene in sexual dimorphism in Hirschsprung disease. Hum Mol Genet 24:685-97
Li, Yunmin; Zheng, Ming; Lau, Yun-Fai Chris (2014) The sex-determining factors SRY and SOX9 regulate similar target genes and promote testis cord formation during testicular differentiation. Cell Rep 8:723-33
Li, Yunmin; Taketo, Teruko; Lau, Yun-Fai Chris (2012) Isolation of fetal gonads from embryos of timed-pregnant mice for morphological and molecular studies. Methods Mol Biol 825:3-16
Kido, Tatsuo; Schubert, Stephanie; Schmidtke, Jörg et al. (2011) Expression of the human TSPY gene in the brains of transgenic mice suggests a potential role of this Y chromosome gene in neural functions. J Genet Genomics 38:181-91
Peng, Hongzhuang; Ivanov, Alexey V; Oh, Hyun J et al. (2009) Epigenetic gene silencing by the SRY protein is mediated by a KRAB-O protein that recruits the KAP1 co-repressor machinery. J Biol Chem 284:35670-80
Kido, Tatsuo; Lau, Yun-Fai Chris (2008) The human Y-encoded testis-specific protein interacts functionally with eukaryotic translation elongation factor eEF1A, a putative oncoprotein. Int J Cancer 123:1573-85
Li, Yunmin; Tabatabai, Z Laura; Lee, Tin-Lap et al. (2007) The Y-encoded TSPY protein: a significant marker potentially plays a role in the pathogenesis of testicular germ cell tumors. Hum Pathol 38:1470-81
Oh, Hyun Ju; Lau, Yun-Fai Chris (2006) KRAB: a partner for SRY action on chromatin. Mol Cell Endocrinol 247:47-52
Kido, Tatsuo; Lau, Yun-Fai Chris (2006) The rat Tspy is preferentially expressed in elongated spermatids and interacts with the core histones. Biochem Biophys Res Commun 350:56-67
Vong, Queenie P; Li, Yunmin; Lau, Yun-Fai Chris et al. (2006) Structural characterization and expression studies of Dby and its homologs in the mouse. J Androl 27:653-61

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