title: Highly diverse fibrinogen-related proteins in the Pacific oyster Crassostrea gigas.
abstract: Fibrinogen-related proteins (FREPs) are a family of proteins with high sequence diversity, and they play crucial roles in invertebrate immune response. However, few studies have characterized this diversity at the whole-genome level. In the present study, approximately 190 predicted FREPs with more than 200 fibrinogen-like (FBG) domains were identified in the genome of the Pacific oyster (Crassostrea gigas), suggesting a historical expansion of this protein family. A sequence analysis showed high numbers of polymorphisms in C. gigas FREP (CgFREP) genes, which may contribute to the versatile immune function of FREPs. A phylogenetic analysis of molluscan FREP sequences indicated lineage-specific duplication of these genes in C. gigas. Additionally, several CgFREP mRNAs were highly expressed in the gills, digestive glands, and hemocytes. Taken together, these findings will help elucidate FREP immune function and facilitate studies of the functional validation of this gene family.
authors: National & Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Baoyu
authors: B
authors: Huang
authors: National & Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors: Linlin
authors: L
authors: Zhang
authors: National & Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China. Electronic address: lili@qdio.ac.cn.
authors: Li
authors: L
authors: Li
authors: National & Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors: Xueying
authors: X
authors: Tang
authors: National & Local Joint Engineering Laboratory of Ecological Mariculture, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China. Electronic address: gfzhang@qdio.ac.cn.
authors: Guofan
authors: G
authors: Zhang
mesh_terms: D000818:Animals; D049896:Crassostrea / Q000235:genetics* / Q000378:metabolism; D005340:Fibrinogen / Q000235:genetics* / Q000378:metabolism; D016678:Genome; D009928:Organ Specificity; D010802:Phylogeny; D020539:Sequence Analysis, Protein
chemical_list: D005340:Fibrinogen
keywords: Crassostrea gigas; FREP; Genome expansion; Innate immune; Sequence diversity