Infrequent bases s4U4-硫尿嘧啶 Inosine 次黄嘌呤 m1G1-甲基鸟嘌呤 m1A1-甲基腺嘌呤 DHU5,6-二氢尿嘧啶 s2C2-硫胞嘧啶 Pseudouridine(ψ)假尿嘧啶:C1-c5Infrequent bases • s4U 4-硫尿嘧啶 • Inosine 次黄嘌呤 • m1G 1-甲基鸟嘌呤 • m1A 1-甲基腺嘌呤 • DHU 5,6-二氢尿嘧啶 • s2C 2-硫胞嘧啶 • Pseudouridine(ψ )假尿嘧啶:C1-C5