title: Functional features of hemocyte subpopulations of the invasive mollusk species Dreissena polymorpha.
abstract: Dreissena polymorpha is a mussel species that invaded many lotic and lentic inland waters in Western Europe and North America. Its positive or negative interactions with biotic and abiotic components of ecosystems are numerous, making this bivalve the subject of numerous studies in ecology, ecophysiology and ecotoxicology. In these contexts, the functional characterization of the zebra mussel hemocytes is of particular interest, as hemocytes are central cells involved in vital functions (immunity, growth, reproduction) of molluscan physiology. Dreissena polymorpha circulating hemocytes populations were characterized by a combination of structural and functional analysis. Assessments were performed during two contrasted physiological periods for mussels (gametogenesis and spawning). Three hemocyte types were identified as hyalinocytes and blast-like cells for agranular hemocytes and one granulocyte population. Flow cytometry analysis of hemocytes functionalities indicated that blast-like cells had low oxidative and mitochondrial activities and low lysosomal content. Hyalinocytes and granulocytes are fully equipped to perform innate immune response. Hyalinocytes exhibit higher oxidative activity than granulocytes. Such observation is not common since numerous studies show that granulocytes are usually cells that have the highest cellular activities. This result demonstrates the significant functional variability of hemocyte subpopulations. Moreover, our findings reveal that spawning period of Dreissena polymorpha was associated with an increase of hyalinocyte percentage in relation to low levels of biological activities in hemocytes. This reduction in hemocyte activity would reflect the important physiological changes associated with the spawning period of this invasive species known for its high reproductive potential.
authors.affiliation: Université de Reims Champagne-Ardenne, UMR_I 02 INERIS-URCA-ULH SEBIO Unité Stress Environnementaux et BIOsurveillance des milieux aquatiques, UFR Sciences Exactes et Naturelles, 51687 Reims Cedex 2, France; INRS, Institut Armand-Frappier, 531 Boulevard des Prairies, Laval, Québec, H7V 1B7, Canada. Electronic address: lauris.evariste@gmail.com.
authors.forename: Lauris
authors.initials: L
authors.lastname: Evariste
authors.affiliation: Institut Universitaire Européen de la Mer, LEMAR UMR CNRS 6539, Technopôle Brest-Iroise, 29280 Plouzané, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Auffret
authors.affiliation: Université de Reims Champagne-Ardenne, URCACyt - Plateau technique de cytométrie en flux, Pôle Santé, 51096 Reims, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Audonnet
authors.affiliation: Université de Reims Champagne-Ardenne, UMR_I 02 INERIS-URCA-ULH SEBIO Unité Stress Environnementaux et BIOsurveillance des milieux aquatiques, UFR Sciences Exactes et Naturelles, 51687 Reims Cedex 2, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Geffard
authors.affiliation: Université de Reims Champagne-Ardenne, UMR_I 02 INERIS-URCA-ULH SEBIO Unité Stress Environnementaux et BIOsurveillance des milieux aquatiques, UFR Sciences Exactes et Naturelles, 51687 Reims Cedex 2, France.
authors.forename: Elise
authors.initials: E
authors.lastname: David
authors.affiliation: INRS, Institut Armand-Frappier, 531 Boulevard des Prairies, Laval, Québec, H7V 1B7, Canada.
authors.forename: Pauline
authors.initials: P
authors.lastname: Brousseau
authors.affiliation: INRS, Institut Armand-Frappier, 531 Boulevard des Prairies, Laval, Québec, H7V 1B7, Canada.
authors.forename: Michel
authors.initials: M
authors.lastname: Fournier
authors.affiliation: Université de Reims Champagne-Ardenne, UMR_I 02 INERIS-URCA-ULH SEBIO Unité Stress Environnementaux et BIOsurveillance des milieux aquatiques, UFR Sciences Exactes et Naturelles, 51687 Reims Cedex 2, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Betoulle
mesh_terms: D000818:Animals; D049875:Dreissena / Q000166:cytology / Q000502:physiology*; D005602:France; D005718:Gametogenesis; D006434:Hemocytes / Q000145:classification / Q000276:immunology / Q000502:physiology; D058865:Introduced Species; D012098:Reproduction; D012621:Seasons
keywords: Hemocytes; Invasive mollusk; Phagocytosis; Zebra mussel