title: Cloning of a rat gene encoding the histo-blood group B enzyme: rats have more than one Abo gene.
abstract: 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.
authors.affiliation: INSERM U419, Institut de Biologie, 9 Quai Moncousu, 44093, Nantes Cedex, France.
authors.forename: Anne Laure
authors.initials: AL
authors.lastname: Turcot
authors.forename: Antoine
authors.initials: A
authors.lastname: Blancher
authors.forename: Béatrice
authors.initials: B
authors.lastname: Le Moullac-Vaidye
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Despiau
authors.forename: Jézabel
authors.initials: J
authors.lastname: Rocher
authors.forename: Francis
authors.initials: F
authors.lastname: Roubinet
authors.forename: Claude
authors.initials: C
authors.lastname: Szpirer
authors.forename: Jacques
authors.initials: J
authors.lastname: Le Pendu
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D019556:COS Cells; D003001:Cloning, Molecular; D006224:Cricetinae; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005091:Exons; D005700:Galactosyltransferases / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D007438:Introns; D051379:Mice; D008969:Molecular Sequence Data; D017350:N-Acetylgalactosaminyltransferases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D011919:Rats, Inbred Strains; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D000017:ABO Blood-Group System; D018076:DNA, Complementary; D012333:RNA, Messenger; C427751:Abo protein, mouse; D005700:Galactosyltransferases; D017350:N-Acetylgalactosaminyltransferases; C003742:UDPgalactosamine-galactose acetylgalactosaminyltransferase; C023155:blood-group-substance alpha-D-galactosyltransferase