The initiation of blood coagulation through the extrinsic pathway is a threshold-mediated event influenced by relative levels of factor VIIa, tissue factor and TFPI activity. Despite intensive study, important questions remain regarding initiation and regulation of the coagulation response. The applicant hypothesizes that novel genes, involved in initiation and regulation of the extrinsic pathway of coagulation, remain to be identified. The current proposal employs the zebrafish as a genetic tool to identify novel genes in this pathway. The novel genes will be identified by chemical mutagenesis of the zebrafish genome followed by a comprehensive screen for mutants with defective thrombin generation by the extrinsic pathway. Screening for zebrafish phenotypes with defective thrombin generation will yield a significant number of mutations in both known and unknown genes involved in the extrinsic pathway of coagulation. Zebrafish that display defective thrombin generation will be rapidly sorted by both biochemical and linkage analyses to eliminate mutations in known genes, and focus will be placed on novel defects affecting the expression, activation or activity of factor VIIa. Identification of novel zebrafish genes will ultimately allow identification of human homologues involved in hemostasis and thrombosis. Identification of human homologues will further our understanding of how the coagulation cascade functions in vivo, suggest novel targets for antithrombotic therapy and provide candidate genetic markers for thrombotic disease.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL063792-04
Application #
6642006
Study Section
Hematology Subcommittee 2 (HEM)
Program Officer
Link, Rebecca P
Project Start
2000-09-01
Project End
2005-07-31
Budget Start
2003-08-01
Budget End
2005-07-31
Support Year
4
Fiscal Year
2003
Total Cost
$216,750
Indirect Cost
Name
University of Texas Health Science Center San Antonio
Department
Anatomy/Cell Biology
Type
Other Domestic Higher Education
DUNS #
800772162
City
San Antonio
State
TX
Country
United States
Zip Code
78229
Day, Kenneth R; Jagadeeswaran, Pudur (2009) Microarray analysis of prothrombin knockdown in zebrafish. Blood Cells Mol Dis 43:202-10
Boycott, Kym M; Bonnemann, Carsten; Herz, Joachim et al. (2009) Mutations in VLDLR as a cause for autosomal recessive cerebellar ataxia with mental retardation (dysequilibrium syndrome). J Child Neurol 24:1310-5
Jagadeeswaran, Pudur; Paris, Ryan; Rao, Prashanth (2006) Laser-induced thrombosis in zebrafish larvae: a novel genetic screening method for thrombosis. Methods Mol Med 129:187-95
Thattaliyath, Bijoy; Cykowski, Matthew; Jagadeeswaran, Pudur (2005) Young thrombocytes initiate the formation of arterial thrombi in zebrafish. Blood 106:118-24
Jagadeeswaran, Pudur (2005) Zebrafish: a tool to study hemostasis and thrombosis. Curr Opin Hematol 12:149-52
Jagadeeswaran, P; Gregory, M; Day, K et al. (2005) Zebrafish: a genetic model for hemostasis and thrombosis. J Thromb Haemost 3:46-53
Day, Kenneth; Krishnegowda, Naveen; Jagadeeswaran, Pudur (2004) Knockdown of prothrombin in zebrafish. Blood Cells Mol Dis 32:191-8
Herrera, Michael; Jagadeeswaran, Pudur (2004) Annual fish as a genetic model for aging. J Gerontol A Biol Sci Med Sci 59:101-7
Prouty, Michael G; Correa, Nidia E; Barker, Lucia P et al. (2003) Zebrafish-Mycobacterium marinum model for mycobacterial pathogenesis. FEMS Microbiol Lett 225:177-82
Fisher, Shannon; Jagadeeswaran, Pudur; Halpern, Marnie E (2003) Radiographic analysis of zebrafish skeletal defects. Dev Biol 264:64-76

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