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 degenerate primers based on sequences found in a continuous region of homology 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 sialyltransferases and encodes a type II transmembrane protein characteristic of glycosyltransferases. In contrast to previously cloned sialyltransferase genes, the expression of the new gene is highly restricted, being abundantly expressed in newborn brain but not in adult brain or any other adult or newborn tissues.