# name
Adhesion of freshwater sponge cells mediated by carbohydrate-carbohydrate interactions requires low environmental calcium

# metadata.dc.description.abstract[].value
Marine ancestors of freshwater sponges had to undergo a
                series of physiological adaptations to colonize harsh and
                heterogeneous limnic environments. Besides reduced salinity,
                river-lake systems also have calcium concentrations far lower
                than seawater. Cell adhesion in sponges is mediated by
                calcium-dependent multivalent self-interactions of sulfated
                polysaccharides components of membrane-bound proteoglycans named
                aggregation factors. Cells of marine sponges require seawater
                average calcium concentration (10\xC2\xA0mM) to sustain adhesion
                promoted by aggregation factors. We demonstrate here that the
                freshwater sponge Spongilla alba can thrive in a calcium-poor
                aquatic environment and that their cells are able to aggregate
                and form primmorphs with calcium concentrations 40-fold lower
                than that required by marine sponges cells. We also find that
                their gemmules need calcium and other micronutrients to hatch
                and generate new sponges. The sulfated polysaccharide purified
                from S. alba has sulfate content and molecular size notably
                lower than those from marine sponges. Nuclear magnetic resonance
                analyses indicated that it is composed of a central backbone of
                non- and 2-sulfated \xCE\xB1- and \xCE\xB2-glucose units
                decorated with branches of \xCE\xB1-glucose. Assessments with
                atomic force microscopy/single-molecule force spectroscopy show
                that S. alba glucan requires 10-fold less calcium than sulfated
                polysaccharides from marine sponges to self-interact
                efficiently. Such an ability to retain multi-cellular morphology
                with low environmental calcium must have been a crucial
                evolutionary step for freshwater sponges to successfully
                colonize inland waters.

# metadata.dc.source[].value
Articles publicats en revistes (ISGlobal)

# metadata.dc.title[].value
Adhesion of freshwater sponge cells mediated by carbohydrate-carbohydrate interactions requires low environmental calcium