Herzig et al. BMC Genomics 2010, 11:100 http://www.biomedcentral.com/1471-2164/11/100 Page 6 of 19 Figure 2 Schematic representation of the bovine (Bos taurus) TRD locus organization. (A) 52 unique TRDV1 genes were identified and are all predicted to be functional (or ORF) and found on chromosome 10, although many of them were unplaced in the Btau_3.1 assembly. Multiple TRDV genes were identified in two or three gene prediction models, as indicated, and labels correspond to those used in Table 1. However, evidence suggests that in each case only a single gene is represented. Genomic organization is shown in those cases when three or more TRDV genes were found within a single scaffolded region. TRA genes are not shown although in many cases occur among the TRDV genes. In addition to some TRDV1 genes, the schematic includes TRDV2-1 on ChrUn.158 (no other TRDV genes are included in the schematic). (B) Genomic organization of the five TRDD genes, 3 TRDJ genes and the single TRDC gene is shown, along with TRDV4 and TRAC. Gene designations, orientations and Bovine Genome Scaffold identifications are as indicated. The determination of TRDV gene orientation was based on the assembly of the Bovine Genome Scaffolds, it is possible that some scaffolds were assembled in an incorrect orientation individually and/ or in relation to other scaffolds. Diagrams are shown to scale with base pair increments beneath the schematics. With the exception of TRAC, TRA genes are not shown. TRDV2-2 and TRDV3 are not shown because those genes were identified on scaffolds lacking additional TRDV genes.