The egg jellies of sea urchins contain sulfated polysaccharides with unusual structures, composed of linear chains of l-fucose or l-galactose with well-defined repetitive units. The specific pattern of sulfation and the position of the glycosidic bond vary among sulfated polysaccharides from different species. These polysaccharides show species specificity in inducing the acrosome reaction, which is a critical event for fertilization. Females of the sea urchin Lytechinus variegatus spawn eggs containing a sulfated fucan with the repetitive sequence [3-alpha-L-Fucp-2(OSO(3))-1 --> 3-alpha-L-Fucp-4(OSO(3))-1 --> 3-alpha-L-Fucp-2,4(OSO(3))-1 --> 3-alpha-L-Fucp-2(OSO(3))-1](n). We now observe that, close to winter, a period of decreased fertility for the sea urchin, the females synthesize a distinct sulfated fucan with a simple structure, composed of 4-sulfated, 3-linked alpha-fucose residues. This sulfated fucan is inactive when tested in vitro for the acrosome reaction using homologous sperm. The amount of egg jellies spawned by females (and their constituent sulfated polysaccharides) varied greatly throughout the year. Apparently, there is a correlation between the temperature of the sea water and the expression of the 4-sulfated, 3-linked sulfated fucan. Overall, we described the occurrence of two isotypes of sulfated fucan in the egg jelly of the sea urchin L. variegatus, which differ in their biological activity and may be involved in the periodicity of the reproductive cycle of the invertebrate.
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http://dx.doi.org/10.1093/glycob/cwm058 | DOI Listing |
Carbohydr Polym
March 2025
State Key Laboratory of Marine Food Processing & Safety Control, College of Food Science and Engineering, Ocean University of China, 1299 Sansha Road, Qingdao 266404, China.
Sulfated fucan from sea cucumber has received growing interest in recent decades. Insight into the primary structure of sulfated fucan is fundamental to elucidate their bioactivity. The sea cucumber Holothuria mexicana possesses a high market demand, while the structure of its sulfated fucan (Hm-FUC) remains unclear.
View Article and Find Full Text PDFSci Rep
January 2025
Morphogenesis of Macro Algae, UMR8227, CNRS - Sorbonne University, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, 29680, France.
The initiation of embryogenesis in the kelp Saccharina latissima is accompanied by significant anisotropy in cell shape. Using monoclonal antibodies, we show that this anisotropy coincides with a spatio-temporal pattern of accumulation of alginates in the cell wall of the zygote and embryo. Alginates rich in guluronates as well as sulphated fucans show a homogeneous distribution in the embryo throughout Phase I of embryogenesis, but mannuronate alginates accumulate mainly on the sides of the zygote and embryo, disappearing as the embryo enlarges at the start of Phase II.
View Article and Find Full Text PDFmSystems
January 2025
School of Biological Sciences, The University of Auckland, Auckland, New Zealand.
The genus () is most often associated with human clinical samples and livestock. However, are also prevalent in the hindgut of the marine herbivorous fish (Silver Drummer), and analysis of their carbohydrate-active enzyme (CAZyme) encoding gene repertoires suggests degrade macroalgal biomass to support fish nutrition. To further explore host-associated traits unique to -derived , we compared 445 high-quality genomes of available in public databases (e.
View Article and Find Full Text PDFMar Drugs
October 2024
Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, 5403 1st Avenue South, Lethbridge, AB T1J 4B1, Canada.
BMC Genomics
October 2024
Integrative Biology of Marine Models Laboratory, Sorbonne Université, CNRS, Station Biologique de Roscoff, Roscoff, France.
Background: Brown algae belong to the Stramenopiles phylum and are phylogenetically distant from plants and other multicellular organisms. This independent evolutionary history has shaped brown algae with numerous metabolic characteristics specific to this group, including the synthesis of peculiar polysaccharides contained in their extracellular matrix (ECM). Alginates and fucose-containing sulphated polysaccharides (FCSPs), the latter including fucans, are the main components of ECMs.
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