title: Identification, evolution and expression of a CD36 homolog in the basal chordate amphioxus Branchiostoma japonicum.
abstract: CD36, as one member of scavenger receptor class B (SRB) family, is a transmembrane glycoprotein and has been associated with diverse normal physiological processes and pathological conditions. However, little is known about it in amphioxus, a model organism for insights into the origin and evolution of vertebrates. In this paper, CD36 homologs in amphioxus were identified. Evolutionary analysis suggested that amphioxus BfCD36F-a/b, which were more similar to vertebrate CD36, might represent the primitive form before the splitting of CD36, SRB1 and SRB2 genes during evolution. Then the BjCD36F-a cDNA was cloned from Branchiostoma japonicum using RACE technology. Real-time PCR and in situ hybridization revealed the expression of BjCD36F-a in all the tissues detected with the highest expression in the hepatic caecum. The BjCD36F-a expression was obviously up-regulated after feeding and down-regulated during fasting, indicating a role of BjCD36F-a in feeding regulation. Besides, the up-regulation expression of BjCD36F-a transcripts was also found after either Lipoteichoic acid (LTA) treatment in the BjCD36F-a-transfected FG cells or Escherichia coli (E. coli) challenge in vivo, implying an immune-related function for BjCD36F-a. Collectively, we identify and characterize a conserved gene that is important in the fundamental process of immune and nutritional regulation. These are the first such data in amphioxus, laying a foundation for further study of their physiological functions.
authors.affiliation: College of Marine Life Science, Ocean University of China, Qingdao 266003, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.forename: Yanping
authors.initials: Y
authors.lastname: Xu
authors.forename: Linfang
authors.initials: L
authors.lastname: Li
authors.forename: Shulei
authors.initials: S
authors.lastname: Wei
authors.forename: Shicui
authors.initials: S
authors.lastname: Zhang
authors.forename: Zhenhui
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000818:Animals; D018955:CD36 Antigens / Q000235:genetics* / Q000378:metabolism*; D002681:China; D002816:Chordata, Nonvertebrate / Q000235:genetics*; D019295:Computational Biology; D017931:DNA Primers; D004926:Escherichia coli; D019143:Evolution, Molecular; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology*; D017403:In Situ Hybridization; D008070:Lipopolysaccharides / Q000494:pharmacology; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D013682:Teichoic Acids / Q000494:pharmacology
chemical_list: D018955:CD36 Antigens; D017931:DNA Primers; D008070:Lipopolysaccharides; D013682:Teichoic Acids; C009900:lipoteichoic acid