POLYMERASE CHAIN-REACTION CLONING OF A DEVELOPMENTALLY-REGULATED MEMBER OF THE SIALYLTRANSFERASE GENE FAMILY

We have cloned a new member of the sialyltransferase gene family from newborn rat brain cDNA using the polymerase chain reaction and degener ate primers based on sequences found in a continuous region of homolog y present in three previously cloned sialyltransferases. The predicted amino acid sequence of the new gene contains 24 of the 31 amino acids that are invariantly conserved in the previously cloned sialyltransfe rases and encodes a type II transmembrane protein characteristic of gl ycosyltransferases. In contrast to previously cloned sialyltransferase genes, the expression of the new gene is highly restricted, being abu ndantly expressed in newborn brain but not in adult brain or any other adult or newborn tissues.