The granulocytes are the main immunocompetent hemocytes in Crassostrea gigas.
Hemocytes comprise diverse cell types with morphological and functional heterogeneity and play indispensable roles in immunological homeostasis of invertebrates. The morphological classification of different hemocytes in mollusk has been studied since the 1970's, yet the involvement of the different sub-populations in immune functions is far from clear. In the present study, three types of hemocytes were morphologically identified and separated as agranulocytes, semi-granulocytes and granulocytes by flow cytometry and Percoll®density gradient centrifugation. The granulocytes were characterized functionally as the main phagocytic and encapsulating population, while semi-granulocytes and agranulocytes exhibited low or no such capacities, respectively. Meanwhile, the lysosome activity and the productions of ROS and NO were all mainly concentrated in granulocytes under both normal and immune-activated situations. Further, the mRNA transcripts of some immune related genes, including CgTLR, CgClathrin, CgATPeV, CgLysozyme, CgDefensin and CgIL-17, were mainly expressed in granulocytes, lower in semi-granulocytes and agranulocytes. These results collectively suggested that the granulocytes were the main immunocompetent hemocytes in oyster C. gigas, and a differentiation relationship among these three sub-population hemocytes was inferred based on the gradual changes in morphological, functional and molecular features.
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Weilin
W
Wang
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Meijia
M
Li
Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China. Electronic address: wanglingling@ms.qdio.ac.cn.
Lingling
L
Wang
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Hao
H
Chen
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Zhaoqun
Z
Liu
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
Zhihao
Z
Jia
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
Limei
L
Qiu
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China.
Linsheng
L
Song
D000818:Animals; D002454:Cell Differentiation; D049896:Crassostrea / Q000276:immunology*; D023082:Defensins / Q000235:genetics; D006098:Granulocytes / Q000276:immunology*; D006434:Hemocytes / Q000276:immunology*; D007121:Immunocompetence; D020381:Interleukin-17 / Q000235:genetics; D008247:Lysosomes / Q000378:metabolism; D008561:Membrane Fusion; D009113:Muramidase / Q000235:genetics; D009569:Nitric Oxide / Q000378:metabolism; D010587:Phagocytosis; D017382:Reactive Oxygen Species / Q000378:metabolism; D051193:Toll-Like Receptors / Q000235:genetics
D023082:Defensins; D020381:Interleukin-17; D017382:Reactive Oxygen Species; D051193:Toll-Like Receptors; D009569:Nitric Oxide; D009113:Muramidase
Crassostrea gigas; Functional features; Granulocytes; Hemocyte separation; Immunocompetent