2026-04-17T14:39:05Zhttps://recercat.cat/oai/request
oai:recercat.cat:2445/1761602025-12-05T14:19:05Zcom_2072_1057col_2072_478902col_2072_478917
RECERCAT author Vilanova, Eduardo author Ciodaro, Priscilla J. author Bezerra, Francisco F. author Santos, Gustavo R. C. author Valle Delgado, Juan J. author Anselmetti, Dario author Fernàndez Busquets, Xavier author Mourão, Paulo A. S. 2021-04-12T08:56:01Z2021-04-12T08:56:01Z2020-02-202021-04-09T18:00:39Z 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. (c) Vilanova et al., 2020 info:eu-repo/semantics/openAccess Citologia Esponges Cytology Sponges Adhesion of freshwater sponge cells mediated by carbohydrate-carbohydrate interactions requires low environmental calcium info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion