Swine use a reverse order of immunoglobulin chain rearrangement compared to humans and mice, and this altered and modified order should have measurable consequences. Here we perform new and defining experiments with developing and mature B cells, characterizing the B cell populations that do not exist in other species. First, we have finally confirmed that light chains κ and λ are rearranged and expressed on the surface before any heavy chain rearrangements using western-blot. And second, we have analyzed a pool of mature B cells on the single-cell level to demonstrate that many κ⁺ mature B cells carry λ transcripts. According to these findings, we believe that there may be more groups of mammals; one of which uses a pre-BCR-driven developmental pathway for B cell generation (like mice and humans), the second group uses a pre-BCR-independent one (like swine), and some may be even intermediate.

与人类和小鼠相比，猪使用相反顺序的免疫球蛋白链重排，这种改变和修改的顺序应该会产生可衡量的后果。在这里，我们对发育和成熟的 B 细胞进行了新的和定义性的实验，表征了其他物种中不存在的 B 细胞群。首先，我们最终证实，在使用蛋白质印迹进行任何重链重排之前，轻链 κ 和 λ 在表面上进行了重排和表达。其次，我们在单细胞水平上分析了一组成熟 B 细胞，以证明许多 κ ⁺成熟的 B 细胞携带 λ 转录本。根据这些发现，我们认为可能存在更多的哺乳动物群体；其中一组使用前 BCR 驱动的 B 细胞生成发育途径（如小鼠和人类），第二组使用前 BCR 独立的发育途径（如猪），有些甚至可能是中间的。