Wednesday 14 May 2014 at 3:00pm

Title: “Evolving understanding of bivalve hemocytes enabled (at least partially) by flow-cytometry”

Speaker: Gary Wikfors, Ph.D.
NOAA Fisheries Service

Abstract:
One-hundred and thirty years after the first discovery of circulating defense cells in an invertebrate animal, origins and developmental sequences in invertebrate hemocytes retain elements of mystery. In the last decade, availability of bench-top flow cytometers and recognition that physiology and function of “white blood cells” (specifically neutrophils) in the human, innate immune system and in invertebrates are highly conserved have enabled morphological and physiological analysis of hemocytes in bivalve mollusks not practical or possible using microscopic observations. Clinical methods have been adapted to categorize and quantify hemocytes in oysters and other bivalves in terms of morphology, defense function, and intracellular physiology. These methods have revealed bivalve hemocytes to be extremely robust in the face of various environmental and biological challenges. Accordingly, stresses that do cause immunomodulation are thought to be relatively severe.

Beyond serving as a tool to evaluate resilience of bivalves to environmental challenges, flow cytometry has provided insights into fundamental developmental and functional relationships between sub-categories of hemocytes, chiefly agranular and granular cells. Combined with advanced imaging techniques and molecular methods, flow cytometry is providing growing evidence of a unified model of hemocyte development and regulation in oysters and other bivalves. Following ten years of primary research in the Milford Laboratory, and drawing heavily from some ground-breaking recent publications of others, I will present evidence for an evolving view of how hemocytes work in oysters and other bivalve mollusks.

Host: J. Sook Chung, Ph.D.