Conserved synteny of the 3′ end of the bovine, human and murine TRA/TRD loci. A schematic representation shows the conserved inter-species organisation of TR genes and regulatory elements at the 3′ end of the TRA/TRD locus. The approximate positions of TRDD (green lines), TRDJ (orange lines), TRAJ (blue lines), TRDC and TRAC (blue blocks), the single inverted TRDV gene (TRDV3 in bovine and human, TRDV5 in mouse – green block) and regulatory elements (yellow circles) are shown. The regulatory elements represented are – TRA enhancer (Eα), TRD enhancer (Eδ), T early alpha (TEA) and conserved sequence block (CSB). The length of the region is also conserved across the species, with the exception of the area occupied by TRDD genes, which is much greater in the bovine TRA/TRD locus (~80 Kb) than in the mouse or human (~10 Kb). The asterisk indicates the approximate location of the 1 Kb gap between contigs DAAA02028052.1 and DAAAA02028053.1.