title: Xenopus laevis L-14 lectin is expressed in a typical pattern in the adult, but is absent from embryonic tissues.
abstract: Soluble, dimeric, lactose-binding lectins with subunit M(r) of approximately 14-16 x 10(3), here called L-14s, are expressed in multiple tissues in all vertebrates that have been examined. L-14s have particular affinity for polylactosamine chains on laminin, co-localize with laminin in some basement membranes, and influence adhesion to laminin and proliferation for some cultured cells. In previous studies of mammals and chickens, L-14s have been found at high levels in a variety of adult tissues, such as muscle and peripheral nerve, but at much higher levels in many embryonic tissues, suggesting a special role in development. To further explore possible roles of L-14 in embryogenesis, we have studied the expression of L-14 in embryonic and adult Xenopus laevis tissues. Xenopus skin, we find that Xenopus L-14 is expressed in the same general distribution as its mammalian homologues. However, we could detect no expression of L-14 in Xenopus embryos using either a sensitive immunoassay for the protein or a sensitive RNase protection assay for its mRNA. Furthermore, use of affinity chromatography to identify other lactose-binding lectins in embryonic tissue revealed only scarce proteins with higher subunit molecular weights. These results suggest that in X.laevis L-14 functions in adult tissues and is not involved in embryogenesis.
authors.affiliation: Department of Psychiatry, University of California at San Fancisco 94143-0984.
authors.forename: P
authors.initials: P
authors.lastname: Marschal
authors.forename: V
authors.initials: V
authors.lastname: Cannon
authors.forename: S H
authors.initials: SH
authors.lastname: Barondes
authors.forename: D N
authors.initials: DN
authors.lastname: Cooper
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D002846:Chromatography, Affinity; D004625:Embryo, Nonmammalian / Q000737:chemistry*; D005260:Female; D037483:Galectin 1; D006388:Hemagglutinins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D007150:Immunohistochemistry; D007785:Lactose / Q000378:metabolism; D007797:Laminin / Q000032:analysis / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D012867:Skin / Q000737:chemistry; D014018:Tissue Distribution; D014982:Xenopus laevis / Q000196:embryology / Q000254:growth & development* / Q000378:metabolism
chemical_list: D037483:Galectin 1; D006388:Hemagglutinins; D007797:Laminin; D012333:RNA, Messenger; D007785:Lactose