Fig. 5.

Coding (d_n) versus silent (d_s) mutations are unequally distributed across the Vδ and Vγ genes. (A) Average d_n (green) and d_s (yellow) substitutions per site across the primate species are shown for the Vδ, Vγ, Jγ, and Jδ genes. Average substitutions per site were calculated for the regions encoding the CDR1 loop (1), CDR2 loop (2), framework region (F), and the entire coding region (V) for the variable genes and for the entire coding region of the J gene segments. Error bars represent SE of these averages. (B) Ratio of d_n to d_s substitutions for each region calculated in A. A ratio of 1, indicated as a dashed purple line in each plot, is consistent with neutral selection. Significant values greater than this are consistent with diversifying selection. Those lower than this are consistent with purifying selection. CDR1 and -2 loop regions are colored in red, framework in orange, and V domain in purple. For those values at which d_s is 0, ratios are shown extending to the maximum value of 4 with a plus sign. (Significant at *P ≤ 0.05, **P ≤ 0.005.)