Fig. 2

The NJ tree inferred from the goat, sheep, pig and dromedary TRBV gene sequences. The evolutionary analysis was conducted in MEGA7 [35]. The optimal tree with the sum of branch length = 12.78116203 is shown. The percentage of replicate trees in which the associated taxa clustered together in the bootstrap test (100 replicates) is shown next to the branches [36]. The tree is drawn to scale with branch lengths in the same units as those of the evolutionary distances used to infer phylogenetic trees. The evolutionary distances were computed using the p-distance method [37] and are in the units of the number of base differences per site. The analysis involved 166 nucleotide sequences. Codon positions included were 1st + 2nd + 3rd + Noncoding. All positions containing gaps and missing data were eliminated. There were a total of 92 positions in the final dataset. The goat TRBV subgroup classification is performed according to the clustering with the orthologous artiodactyl TRBV subgroups. The different colours highlight the distribution of the phylogenetic groups. The gene functionality according to IMGT rules (F: functional, ORF: open reading frame, P: pseudogene) is indicated. The IMGT 6-letter for species (Caphir, Oviari, Susscr and Camdro,) standardized abbreviation for taxon is used