title: Characterization, organization and expression of AmphiLysC, an acidic c-type lysozyme gene in amphioxus Branchiostoma belcheri tsingtauense.
abstract: The study on lysozymes remains open in amphioxus, a cephalochordate. Here we show the existence of c-type lysozyme gene (AmphiLysC) in amphioxus, first such data in the basal chordates including urochordate and cephalochordate. This is in contrast to the absence of c-type lysozyme genes in urochordate. It is found that there exist two copies of c-type lysozyme genes in amphioxus genome, and their gene organization is similar to vertebrate c-type lysozyme genes with respect to the number and the size of both exons and introns. AmphiLysC possesses main features characteristic of the digestive c-type lysozyme such as lower number of basic amino acids (low pI values) and pH-optimum in acidic range. Moreover, AmphiLysC is predominantly expressed in the gut. These indicate that AmphiLysC is possibly a digestive c-type enzyme. However, the ubiquitous expression of AmphiLysC in non-digestive tissues such as ovaries, testes, notochord, gill and muscle suggests that it may also play a non-digestive role like antibacterial activity. It is highly likely that AmphiLysC is an enzyme with a combined function of digestion and bacteriolysis.
authors.affiliation: Department of Marine Biology, Ocean University of China, Qingdao, 266003, P.R. China.
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Shicui
authors.initials: S
authors.lastname: Zhang
authors.forename: Zhenhui
authors.initials: Z
authors.lastname: Liu
authors.forename: Hongyan
authors.initials: H
authors.lastname: Li
authors.forename: Anlong
authors.initials: A
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002816:Chordata, Nonvertebrate / Q000235:genetics* / Q000378:metabolism; D018388:Codon, Terminator; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005091:Exons; D018628:Gene Dosage; D015870:Gene Expression; D007438:Introns; D008969:Molecular Sequence Data; D009113:Muramidase / Q000737:chemistry / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D021382:Protein Sorting Signals; D012333:RNA, Messenger / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D018388:Codon, Terminator; D018076:DNA, Complementary; D021382:Protein Sorting Signals; D012333:RNA, Messenger; D009113:Muramidase