title: Terminal alpha-d-mannosides are critical during sea urchin gastrulation.
abstract: The sea urchin embryo is a United States National Institutes of Health (NIH) designated model system to study mechanisms that may be involved in human health and disease. In order to examine the importance of high-mannose glycans and polysaccharides in gastrulation, Lytechinus pictus embryos were incubated with Jack bean α-mannosidase (EC 3.2.1.24), an enzyme that cleaves terminal mannose residues that have α1-2-, α1-3-, or α1-6-glycosidic linkages. The enzyme treatment caused a variety of morphological deformations in living embryos, even with α-mannosidase activities as low as 0.06 U/ml. Additionally, formaldehyde-fixed, 48-hour-old L. pictus embryos were microdissected and it was demonstrated that the adhesion of the tip of the archenteron to the roof of the blastocoel in vitro is abrogated by treatment with α-mannosidase. These results suggest that terminal mannose residues are involved in the adhesion between the archenteron and blastocoel roof, perhaps through a lectin-like activity that is not sensitive to fixation.
authors.affiliation: Department of Biology and Center for Cancer and Developmental Biology,California State University,Northridge,California 91330-8303,USA.
authors.forename: Heghush
authors.initials: H
authors.lastname: Aleksanyan
authors.affiliation: Department of Biology and Center for Cancer and Developmental Biology,California State University,Northridge,California 91330-8303,USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Liang
authors.affiliation: Department of Biology and Center for Cancer and Developmental Biology,California State University,Northridge,California 91330-8303,USA.
authors.forename: Stan
authors.initials: S
authors.lastname: Metzenberg
authors.affiliation: Department of Biology and Center for Cancer and Developmental Biology,California State University Northridge,18111 Nordhoff Street,Northridge,California 91330-8303,USA.
authors.forename: Steven B
authors.initials: SB
authors.lastname: Oppenheimer
mesh_terms: D000818:Animals; D004625:Embryo, Nonmammalian / Q000378:metabolism; D005775:Gastrula / Q000254:growth & development / Q000378:metabolism; D054262:Gastrulation / Q000502:physiology*; D008362:Mannosides / Q000737:chemistry* / Q000378:metabolism*; D012617:Sea Urchins / Q000196:embryology* / Q000378:metabolism; D043323:alpha-Mannosidase / Q000737:chemistry / Q000378:metabolism
chemical_list: D008362:Mannosides; D043323:alpha-Mannosidase
keywords:    d-Mannose; Archenteron; Blastocoel roof; Gastrulation; Sea urchin; α-Mannosidase