FISH mapping of the porcine vWF gene to chromosome 5q21 extends synteny homology with human Chromosome 12

von Willebrand Factor (vWF) is a large adhesive glycoprotein that mediates platelet adhesion at sites of vascular injury, carries F8C (coagulation factor VIIIc) in plasma and protects it from degradation, and supports the development of occlusive thrombosis in animal models. Porcine and human vWF proteins appear to function similarly in their respective species. There is little information on porcine vWF at a molecular level and the gene has not been localized on the pig genome. Comparison of the chromosomal location of the murine and human vWF gene has shown important differences in genomic organization of this gene in these two species. The purpose of this paper is to report the location of the vWF gene in the porcine genome and compare its chromosomal location with other species. Three strains of pigs relative to vWF (i.e., normal, heterozygous and homozygous for von Willebrand disease - vWD) have been housed at the Francis Owen Blood Research Laboratory (FO-BRL), University of North Carolina, Chapel Hill, NC, as part of a closed colony for over 25 generations. In this closed colony, porcine vWD is inherited as an autosomal recessive trait and breeding strategies are designed to produce all three genotypes. A normal pig, relative to the vWF genotype, was selected as a source of RNA for these experiments. A 4.5 kb fragment corresponding to the 3' end of pig vWF cDNA was synthesised by reverse transcription and polymerase chain reaction amplification, gel purified by electroelution (UEA, IBI, CT), and cloned into the TA cloning vector, pCRII (Invitrogen). Comparisons between the 3' end of this fragment and full length human vWF cDNA revealed significant homologies (>90%) between the nucleotide and deduced amino acid sequences, indicating that the 4.5 kb fragment represents the 3' end of pig vWF cDNA (W. T. Seaman, manuscript in preparation). The DNA fragment was labeled with biotin using the GIBCO-BRL Bionick labeling system (BRL 18246-015). Unincorporated nucleotides were separated from the labeled DNA by spinning through a Sephadex G-50 column. The size of the labeled probe (approximately 500 bp) was confirmed on a 1% agarose gel in TAE buffer.