title: Cloning and characterization of a novel mouse Siglec, mSiglec-F: differential evolution of the mouse and human (CD33) Siglec-3-related gene clusters.
abstract: A novel mouse Siglec (mSiglec-F) belonging to the subfamily of Siglec-3-related Siglecs has been cloned and characterized. Unlike most human Siglec-3 (hSiglec-3)-related Siglecs with promiscuous linkage specificity, mSiglec-F shows a strong preference for alpha2-3-linked sialic acids. It is predominantly expressed in immature cells of the myelomonocytic lineage and in a subset of CD11b (Mac-1)-positive cells in some tissues. As with previously cloned Siglec-3-related mSiglecs, the lack of strong sequence similarity to a singular hSiglec made identification of the human ortholog difficult. We therefore conducted a comprehensive comparison of Siglecs between the human and mouse genomes. The mouse genome contains eight Siglec genes, whereas the human genome contains 11 Siglec genes and a Siglec-like gene. Although a one-to-one orthologous correspondence between human and mouse Siglecs 1, 2, and 4 is confirmed, the Siglec-3-related Siglecs showed marked differences between human and mouse. We found only four Siglec genes and two pseudogenes in the mouse chromosome 7 region syntenic to the Siglec-3-related gene cluster on human chromosome 19, which, in contrast, contains seven Siglec genes, a Siglec-like gene, and thirteen pseudogenes. Although analysis of gene maps and exon structures allows tentative assignments of mouse-human Siglec ortholog pairs, the possibility of unequal genetic recombination makes the assignments inconclusive. We therefore support a temporary lettered nomenclature for additional mouse Siglecs. Current information suggests that mSiglec-F is likely a hSiglec-5 ortholog. The previously reported mSiglec-3/CD33 and mSiglec-E/MIS are likely orthologs of hSiglec-3 and hSiglec-9, respectively. The other Siglec-3-like gene in the cluster (mSiglec-G) is probably a hSiglec-10 ortholog. Another mouse gene (mSiglec-H), without an apparent human ortholog, lies outside of the cluster. Thus, although some duplications of Siglec-3-related genes predated separation of the primate and rodent lineages (about 80-100 million years ago), this gene cluster underwent extensive duplications in the primate lineage thereafter.
authors.affiliation: Department of Medicine, the Glycobiology Research and Training Center, University of California, San Diego, La Jolla, California 92093-0687, USA.
authors.forename: T
authors.initials: T
authors.lastname: Angata
authors.forename: R
authors.initials: R
authors.lastname: Hingorani
authors.forename: N M
authors.initials: NM
authors.lastname: Varki
authors.forename: A
authors.initials: A
authors.lastname: Varki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D015703:Antigens, CD / Q000737:chemistry / Q000235:genetics*; D015214:Antigens, Differentiation, Myelomonocytic / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D001853:Bone Marrow / Q000378:metabolism; D019556:COS Cells; D019070:Cell Lineage; D002874:Chromosome Mapping; D002888:Chromosomes, Human, Pair 19; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D019143:Evolution, Molecular; D005434:Flow Cytometry; D016678:Genome; D006801:Humans; D007150:Immunohistochemistry; D037102:Lectins / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008957:Models, Genetic; D008969:Molecular Sequence Data; D005810:Multigene Family; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D010802:Phylogeny; D017354:Point Mutation; D011485:Protein Binding; D012313:RNA / Q000378:metabolism; D051381:Rats; D011956:Receptors, Cell Surface; D017386:Sequence Homology, Amino Acid; D063268:Sialic Acid Binding Ig-like Lectin 3; D063265:Sialic Acid Binding Immunoglobulin-like Lectins; D012794:Sialic Acids / Q000378:metabolism
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; C571163:CD33 protein, human; C571165:Cd33 protein, mouse; D018076:DNA, Complementary; D037102:Lectins; D011956:Receptors, Cell Surface; C426228:SIGLEC10 protein, human; C114531:SIGLEC5 protein, human; D063268:Sialic Acid Binding Ig-like Lectin 3; D063265:Sialic Acid Binding Immunoglobulin-like Lectins; D012794:Sialic Acids; C443130:Siglecf protein, mouse; D012313:RNA; D019158:N-Acetylneuraminic Acid