title: Cloning and characterization of wnt4a gene and evidence for positive selection in half-smooth tongue sole (Cynoglossus semilaevis).
abstract: Wnt4 gene plays a role in developmental processes in mammals. However, little is known regarding its function in teleosts. We cloned and characterized the full-length half-smooth tongue sole (Cynoglossus semilaevis) wnt4a gene (CS-wnt4a). CS-wnt4a cDNA was 1746 bp in length encoding 353aa. CS-wnt4a expression level was highest in the testis, and gradually increased in the developing gonads until 1 year of age. In situ hybridization revealed that CS-wnt4a expression level was highest in stage II oocytes and sperm in the adult ovary and testis, respectively. CS-wnt4a expression level was significantly up-regulated in the gonads after exposure to high temperature. The level of methylation of the CS-wnt4a first exon was negatively correlated with the expression of CS-wnt4a. The branch-site model suggested that vertebrate wnt4a differed significantly from that of wnt4b, and that the selective pressures differed between ancestral aquatic and terrestrial organisms. Two positively selected sites were found in the ancestral lineages of teleost fish, but none in the ancestral lineages of mammals. One positively selected site was located on the α-helices of the 3D structure, the other on the random coil. Our results are of value for further study of the function of wnt4 and the mechanism of selection.
authors.affiliation: 1] Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao 266071, China [2] Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China.
authors.forename: Qiaomu
authors.initials: Q
authors.lastname: Hu
authors.affiliation: Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao 266071, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao 266071, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao 266071, China.
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.affiliation: Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences; Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Qingdao 266071, China.
authors.forename: Songlin
authors.initials: S
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D043344:Chordata / Q000254:growth & development / Q000378:metabolism*; D003001:Cloning, Molecular; D019175:DNA Methylation; D019143:Evolution, Molecular; D005260:Female; D006066:Gonads / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D013094:Spermatozoa / Q000378:metabolism; D013696:Temperature; D013737:Testis / Q000378:metabolism; D014018:Tissue Distribution; D015854:Up-Regulation; D060528:Wnt4 Protein / Q000145:classification / Q000235:genetics* / Q000378:metabolism*
chemical_list: D060528:Wnt4 Protein