title: Conserved hemopoietic transcription factor Cg-SCL delineates hematopoiesis of Pacific oyster Crassostrea gigas.
abstract: Hemocytes are the effective immunocytes in bivalves, which have been reported to be derived from stem-like cells in gill epithelium of oyster. In the present work, a conserved haematopoietic transcription factor Tal-1/Scl (Stem Cell Leukemia) was identified in Pacific oyster (Cg-SCL), and it was evolutionarily close to the orthologs in deuterostomes. Cg-SCL was highly distributed in the hemocytes as well as gill and mantle. The hemocyte specific genes Integrin, EcSOD and haematopoietic transcription factors GATA3, C-Myb, c-kit, were down-regulated when Cg-SCL was interfered by dsRNA. During the larval developmental stages, the mRNA transcripts of Cg-SCL gradually increased after fertilization and peaked at early trochophore larvae stage (10 hpf, hours post fertilization), then sharply decreased in late trochophore larvae stage (15 hpf) before resuming in umbo larvae (120 hpf). Whole-mount immunofluorescence assay further revealed that the immunoreactivity of Cg-SCL appeared in blastula larvae with two approximate symmetric spots, and this expression pattern lasted in gastrula larvae. By trochophore, the immunoreactivity formed a ring around the dorsal region and then separated into two remarkable spots at the dorsal side in D-veliger larvae. After bacterial challenge, the mRNA expression levels of Cg-SCL were significantly up-regulated in the D-veliger and umbo larvae, indicating the available hematopoietic regulation in oyster larvae. These results demonstrated that Cg-SCL could be used as haematopoietic specific marker to trace potential developmental events of hematopoiesis during ontogenesis of oyster, which occurred early in blastula stage and maintained until D-veliger larvae.
authors.affiliation: 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.
authors.forename: Xiaorui
authors.initials: X
authors.lastname: Song
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.affiliation: 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.
authors.forename: Hao
authors.initials: H
authors.lastname: Chen
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Mingzhe
authors.initials: M
authors.lastname: Sun
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Zhongxiu
authors.initials: Z
authors.lastname: Liang
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China. Electronic address: lshsong@dlou.edu.cn.
authors.forename: Linsheng
authors.initials: L
authors.lastname: Song
mesh_terms: D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics*; D049896:Crassostrea / Q000235:genetics*; D006410:Hematopoiesis / Q000235:genetics*; D006434:Hemocytes / Q000378:metabolism; D007814:Larva; D010802:Phylogeny; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger
keywords: Hematopoiesis; Larval developmental stages; Pacific oyster; Transcription factor Tal-1/Scl; mRNA expression