Rationale and Objectives. Completion of the human genome sequence provides the starting point for understanding the genetic complexity of humans and how genetic variation contributes to diverse phenotypes and disease. It is clear that model organisms have played an invaluable role in the synthesis of this understanding. It is also noted that additional species must be sequenced to resolve the genetic complexity of human evolution and to effectively extrapolate genetic information from comparative (veterinary) medicine to human medicine. Certainly the pig has been a valuable biomedical model organism and its role will expand in the future. The pig also represents an evolutionary clade distinct from primates or rodents, and thus, provides considerable power in the analysis of human genomic sequences. The pig, a domesticated eutherian mammal, has co-evolved with humans and represents a taxa with diverse selected phenotypes [Rothschild and Ruvinsky, 1998]. The pig has a central position in the scientific and veterinary medical communities that supports the utility of securing genome sequence information. Thus, this "white paper" provides scientific justification for sequencing the porcine genome (6X coverage) to identify new genes and novel regulatory elements in the pig and in humans, mice and rats. The porcine genome will serve as a reference non-primate, non-rodent, eutherian genome. The recent ability to genetically modify the porcine genome, genetically manipulate embryonic fibroblasts, and �clone� genetically modified somatic cells through nuclear transfer attests to how the pig can provide relevant genetic models (of appropriate phenotypes). This further demonstrates the unique role the pig will play in biomedical research, hence warranting the value for genomic sequencing.

The porcine genome is uniquely positioned for genomic sequencing because of the advanced stage of the necessary reagents. A porcine BAC map with 20X coverage, constructed via an international consortium, will be fingerprinted and all fingerprinted clones end-sequenced by June, 2003. This resource will permit selection of the minimum tilling path of BAC clones to be sequenced and complement a whole-genome shotgun sequencing approach. This approach was selected since its affords increased efficiency, saving time and money, and yields a better product since the BAC map will be completed prior to initiation of genomic sequencing. Linking the sequence to the BAC clone map allows for subsequent targeted closure of the genomic sequence in regions of particular interest. This strategy is justified through the outcomes associated with the human, mouse, and rat sequencing efforts that were done in parallel with the BAC map development.