title: Three in one: Identification, expression and enzymatic activity of lysozymes in amphioxus.
abstract: The lysozymes identified so far in animals belong to the g-type, c-type, and i-type. Vertebrate animals possess only the former two types, i.e., g- and c-types, while all the three types have been reported in invertebrates. Here we demonstrate that (1) three cDNAs that encode g-, c-, and i-type lysozymes, respectively, were identified in a single species of the amphioxus Branchiostoma japonicum; (2) all the 3-type genes displayed distinct tissue-specific expression pattern; (3) recombinant g-, c-, and i-type lysozymes all exhibited enzymatic activities; and (4) native g-, c-, and i-type lysozymes were identified in the different tissues of amphioxus. Collectively, these results suggest the presence of all the 3-type lysozymes in a single animal species, first such data ever reported. The presence of biologically active i-type lysozyme in amphioxus also suggests that i-type lysozyme gene is retained at least in Protochordata, contrasting to the previous proposal that i-type lysozyme gene has been lost in a common ancestor of all chordates.
authors: Key Laboratory of Tobacco Biology and Processing, Ministry of Agriculture, Tobacco Research Institute of Chinese Academy of Agricultural Sciences, Qingdao 266101, China; Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
authors: Na
authors: N
authors: Xu
authors: Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
authors: Junli
authors: J
authors: Pan
authors: Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
authors: Shousheng
authors: S
authors: Liu
authors: School of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge, LA 70830, USA. Electronic address: qxue@lsu.edu.
authors: Qinggang
authors: Q
authors: Xue
authors: Laboratory for Evolution & Development, Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China. Electronic address: sczhang@ouc.edu.cn.
authors: Shicui
authors: S
authors: Zhang
mesh_terms: D000818:Animals; D020134:Catalytic Domain; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D064175:Lancelets / Q000201:enzymology* / Q000235:genetics; D008958:Models, Molecular; D009113:Muramidase / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D009928:Organ Specificity; D010802:Phylogeny; D017433:Protein Structure, Secondary
chemical_list: D009113:Muramidase
keywords: Amphioxus; C-type lysozyme; G-type lysozyme; I-type lysozyme; Protochordate