Nurse shark T‐cell receptors employ somatic hypermutation preferentially to alter alpha/delta variable segments associated with alpha constant region

In addition to canonical TCR and BCR, cartilaginous fish assemble noncanonical TCR that employ various B‐cell components. For example, shark T cells associate alpha (TCR‐α) or delta (TCR‐δ) constant (C) regions with Ig heavy chain (H) variable (V) segments or TCR‐associated Ig‐like V (TAILV) segments to form chimeric IgV‐TCR, and combine TCRδC with both Ig‐like and TCR‐like V segments to form the doubly rearranging NAR‐TCR. Activation‐induced...