Siat8d genetic mapping PST-1 Siat8d|ST8SiaIV|PST|PST-1 protein coding gene O ST8SiaIV St8sia4 http://identifiers.org/mgd/MGI:106018 Gene MGI:106018 - PST ST8 alpha-N-acetyl-neuraminide alpha-2,8-sialyltransferase 4