Figure 10

Hypothetic evolutionary model for the ovine TRG loci. The genes are represented (not in scale) as small coloured boxes with transcriptional orientation from left to right, while the enhancer-like sequences are indicated with a red coloured E. It is not clear whether the three-Js conformation of the most ancient cassette preceded or followed the formation of the ancestors of TRGC6 and TRGC5 cassettes (the most probable hypothesis is shown in lines 1 and 2). Rectangles, squared parentheses and wavy lines are used to indicate the regions involved in duplicative events, deletions and conversions, respectively. Duplications of a cassette or a gene are indicated by two blue coloured head-arrows or by a single dark yellow arrow while for the chromosome break a flash of lightning was used. The likely insertion of repeats, listed in Table 2 and shown in Fig. 9, is indicated with the corresponding number. Panels 1–8 are discussed in Results.