Record Details
Sulfation of fucoidan in Fucus embryos and its possible role in localization
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Sulfation of fucoidan in Fucus embryos and its possible role in localization |
| Names |
Crayton, Michele Allen
(creator) Quatrano, Ralph S. (advisor) |
| Date Issued | 1974-05-06 (iso8601) |
| Note | Graduation date: 1974 |
| Abstract | Under defined cultural conditions, zygotes of the brown alga Fucus distichus L. Powell divide synchronously to form two-celled embryos at approximately 24 hours after fertilization. These two cells differ from one another in gross morphology, ultrastructure, cytochemistry, and developmental fate. Cytochemical staining and autoradiography indicated that a sulfated polysaccharide was localized in one of the two cells. This highly polar embryo at 24 hours developed from an apolar egg, with no apparent localization of the sulfated polysaccharide. Before 10 hours, little incorporation of ³⁵S (Na₂³⁵SO₄) was detected in an acid-soluble carbohydrate fraction containing a fucan-sulfate (fucoidan). Between 10-16 hours, the time of rhizoid initiation and several hours before cell division, an increased rate of ³⁵S incorporation into fucoidan was observed. The label was bound as an ester-linked sulfate to fucoidan. Data indicated that this acidic polysaccharide was not metabolically active and was present in a relatively unsulfated state before 10 hours. Therefore, the sulfate accumulation into fucoidan during this post-fertilization period appeared to be due to sulfation of a pre-existing polymer. Biochemical and cytochemical evidence demonstrated that sulfation of fucoidan was blocked when zygotes developed in artificial sea water containing 10 mM L-methionine instead of sulfate. Under these conditions, however, rhizoids developed normally. Thus, the process of sulfation was separated from, and appeared independent of, polar development. The degree of sulfation reached in vivo during the time of rhizoid formation was sufficient for the migration of fucoidan in an electric field on acrylamide and agarose gels. A direct correlation was demonstrated between the amount of sulfate bound to fucoidan and the rate of migration of fucoidan in an electric field. The possible role of sulfation as a mechanism for the localization of fucoidan via an electrophorectic mechanism in vivo, and the possible effect of localized fucoidan on future cell determination, were discussed. |
| Genre | Thesis/Dissertation |
| Topic | Botany -- Embryology |
| Identifier | http://hdl.handle.net/1957/45954 |
