Cloning of a rat gene encoding the histo-blood group B enzyme: rats have more than one Abo gene

Glycobiology. 2003 Dec;13(12):919-28. doi: 10.1093/glycob/cwg087. Epub 2003 Jun 10.


A genomic DNA fragment corresponding to exon 7 of the human ABO gene was amplified from rats of several inbred and outbred strains. Five different sequences were obtained, four of them corresponding to A-type sequences and one to a B-type sequence based on the amino acids equivalent to residues at positions 266 and 268 of the human enzymes. In rats from inbred strains, a single A-type sequence and the unique B-type sequence were found, whereas some animals of outbred strains presented two or three A-type sequences along with the B-type sequence. The complete coding sequence of the B-type gene was obtained; identification of the exon-intron boundaries, determined by comparison with rat genomic sequences from data banks, revealed that the rat B-type gene structure is identical with that of the mouse Abo gene. Compared with the human ABO gene and the rat A gene, it lacks exon 4. Like the rat A gene (symbol: Abo), the rat B gene (symbol: Abo2) is located on chromosome 3q11-q12. It could be shown by transfection experiments that the B-type cDNA encodes an active B transferase. A transcript of the B gene was found ubiquitously, whereas the B antigen was only detected in a restricted set of tissues. These data indicate that rats have at least two distinct Abo genes, one monomorphic gene encoding a B-specific enzyme and one or more genes in some cases encoding an A-specific enzyme.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ABO Blood-Group System / genetics*
  • Amino Acid Sequence
  • Animals
  • CHO Cells
  • COS Cells
  • Cloning, Molecular
  • Cricetinae
  • DNA, Complementary / genetics
  • DNA, Complementary / metabolism
  • Exons
  • Galactosyltransferases / genetics*
  • Galactosyltransferases / metabolism
  • Humans
  • Introns
  • Mice
  • Molecular Sequence Data
  • N-Acetylgalactosaminyltransferases / genetics
  • N-Acetylgalactosaminyltransferases / metabolism
  • RNA, Messenger / biosynthesis
  • Rats
  • Rats, Inbred Strains
  • Rats, Sprague-Dawley
  • Rats, Wistar
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid


  • ABO Blood-Group System
  • DNA, Complementary
  • RNA, Messenger
  • Abo protein, mouse
  • Galactosyltransferases
  • N-Acetylgalactosaminyltransferases
  • UDPgalactosamine-galactose acetylgalactosaminyltransferase
  • blood-group-substance alpha-D-galactosyltransferase

Associated data

  • GENBANK/AB081649
  • GENBANK/AB081650
  • GENBANK/AB081651
  • GENBANK/AF264018
  • GENBANK/AF469945
  • GENBANK/AF469946