title: Molecular cloning, sequence analysis and phylogeny of first caudata g-type lysozyme in axolotl (Ambystoma mexicanum).
abstract: Lysozymes are key proteins that play important roles in innate immune defense in many animal phyla by breaking down the bacterial cell-walls. In this study, we report the molecular cloning, sequence analysis and phylogeny of the first caudate amphibian g-lysozyme: a full-length spleen cDNA library from axolotl (Ambystoma mexicanum). A goose-type (g-lysozyme) EST was identified and the full-length cDNA was obtained using RACE-PCR. The axolotl g-lysozyme sequence represents an open reading frame for a putative signal peptide and the mature protein composed of 184 amino acids. The calculated molecular mass and the theoretical isoelectric point (pl) of this mature protein are 21523.0 Da and 4.37, respectively. Expression of g-lysozyme mRNA is predominantly found in skin, with lower levels in spleen, liver, muscle, and lung. Phylogenetic analysis revealed that caudate amphibian g-lysozyme had distinct evolution pattern for being juxtaposed with not only anura amphibian, but also with the fish, bird and mammal. Although the first complete cDNA sequence for caudate amphibian g-lysozyme is reported in the present study, clones encoding axolotl's other functional immune molecules in the full-length cDNA library will have to be further sequenced to gain insight into the fundamental aspects of antibacterial mechanisms in caudate.
authors.affiliation: 1 Department of Bioscience and Biotechnology, Dalian University of Technology, Dalian 116023, China.
authors.forename: Haining
authors.initials: H
authors.lastname: Yu
authors.forename: Jiuxiang
authors.initials: J
authors.lastname: Gao
authors.forename: Yiling
authors.initials: Y
authors.lastname: Lu
authors.forename: Huijuan
authors.initials: H
authors.lastname: Guang
authors.forename: Shasha
authors.initials: S
authors.lastname: Cai
authors.forename: Songyan
authors.initials: S
authors.lastname: Zhang
authors.forename: Yipeng
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000558:Ambystoma mexicanum / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D005786:Gene Expression Regulation / Q000502:physiology; D008969:Molecular Sequence Data; D009113:Muramidase / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D059467:Transcriptome
chemical_list: D009113:Muramidase