Abstract
Mouse-human hybrid clones were tested for the presence of human hexose-1-phosphate uridylyl-transferase (EC 2.7.7.12;UDPglucose:alpha-D-galactose-1-phosphate uridylyltransferase). Two criteria, starch gel electrophoresis and double-immunodiffusion against a human transferase-specific antibody, were used to identify human enzyme in the hybrid clones. Seventeen of 33 hybrid clones analyzed were found to contain human transferase by both criteria. Karyological analysis of the hybrid clones showed concordant segregation of human transferase with human chromosome 3. Human galactokinase was asyntenic with human transferase. We thus assign this gene to human chromosome 3.