Date Published: September 24, 2012
Publisher: Hindawi Publishing Corporation
Author(s): Arunima Ghosh, Andy Vo, Beverly K. Twiss, Colin A. Kretz, Mary A. Jozwiak, Robert R. Montgomery, Jordan A. Shavit.
von Willebrand disease (VWD) is the most common inherited human bleeding disorder and is caused by quantitative or qualitative defects in von Willebrand factor (VWF). VWF is a secreted glycoprotein that circulates as large multimers. While reduced VWF is associated with bleeding, elevations in overall level or multimer size are implicated in thrombosis. The zebrafish is a powerful genetic model in which the hemostatic system is well conserved with mammals. The ability of this organism to generate thousands of offspring and its optical transparency make it unique and complementary to mammalian models of hemostasis. Previously, partial clones of zebrafish vwf have been identified, and some functional conservation has been demonstrated. In this paper we clone the complete zebrafish vwf cDNA and show that there is conservation of domain structure. Recombinant zebrafish Vwf forms large multimers and pseudo-Weibel-Palade bodies (WPBs) in cell culture. Larval expression is in the pharyngeal arches, yolk sac, and intestinal epithelium. These results provide a foundation for continued study of zebrafish Vwf that may further our understanding of the mechanisms of VWD.
Vertebrates possess a complex closed circulatory system that requires balanced coordination of various factors that serve to maintain blood flow as well as prevent exsanguination when the system is breached. This is known as hemostasis and consists of a complex array of cellular elements, as well as a network of proteins known as the coagulation cascade. The latter have been highly conserved at the genomic level throughout vertebrate evolution, including mammals, birds, reptiles, and fish [1–3].
VWD is due to quantitative or qualitative deficiency of VWF and has been described in several mammals, including human, horse, cat, pig, rabbit, and dog [7, 8]. Identification and characterization of the human VWF cDNA [30–33] enabled the eventual identification of many of these pathogenic mutations as well as partial or full length sequence information in numerous mammalian species . The zebrafish genome project  assisted in the identification of much of the vwf cDNA [15, 16], but this did not include the complete 5′ and 3′ UTRS. We have now completed cloning and characterization of the full length zebrafish vwf cDNA.