title: HcTyr and HcTyp-1 of Hyriopsis cumingii, novel tyrosinase and tyrosinase-related protein genes involved in nacre color formation.
abstract: Tyrosinase is an important enzyme that is involved in biological processes such as pigmentation, wound healing, sclerotization of the cuticles, oxygen transport and innate immunity. As nacre color has an effect on pearl color, we studied the effect of tyrosinase on nacre color in Hyriopsis cumingii (an important freshwater pearl-producing mussel) by cloning novel tyrosinase protein and tyrosinase-related protein genes (HcTyr and HcTyp-1 respectively) from the mantle. The predicted amino acid sequences of HcTyr and HcTyp-1 contain conserved domains, and HcTyp-1 contains an additional chitin-binding domain. Two different types of mussels, purple shelled and white shelled, were used to investigate the role of tyrosinase in shell color. HcTyr and HcTyp-1 mRNAs were mainly expressed in the mantle, but the expression of HcTyr was higher in the purple mussel than in the white mussel while the expression of HcTyp-1 was higher in the white mussel. Strong and specific mRNA signals for HcTyp-1 were detected in the dorsal epithelial cells of the mantle pallial and some signals were detected in the epithelial cells of the periostracal groove, so HcTyp-1 may be involved in periostracum and nacreous layer formation. Strong and specific mRNA signals were also detected in the dorsal epithelial cells of the mantle pallial, so HcTyr may be involved in nacre formation. Further, the tyrosinase activity of the mantle in the purple mussel was higher than that in the white mussel. These findings indicate that HcTyr and HcTyp-1 may be involved in the formation of nacre color in H. cumingii.
authors.affiliation: Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China.
authors.forename: Xiajun
authors.initials: X
authors.lastname: Chen
authors.affiliation: Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China; Shanghai Engineering Research Centre of Aquaculture, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Zhiyi
authors.initials: Z
authors.lastname: Bai
authors.affiliation: Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China.
authors.forename: Liting
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China; Aquaculture Division, E-Institute of Shanghai Universities, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Centre of Aquaculture, Shanghai Ocean University, Shanghai 201306, China. Electronic address: jlli2009@126.com.
authors.forename: Jiale
authors.initials: J
authors.lastname: Li
mesh_terms: D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic; D014442:Monophenol Monooxygenase / Q000235:genetics*; D060734:Nacre / Q000378:metabolism*; D010802:Phylogeny; D010858:Pigmentation / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D049876:Unionidae / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D060734:Nacre; D014442:Monophenol Monooxygenase
keywords: Freshwater mussel; Hyriopsis cumingii; Nacre color; Tyrosinase