scholarly journals Evolution and functional analysis of the Pif97 gene of the Pacific oyster Crassostrea gigas

2013 ◽  
Vol 59 (1) ◽  
pp. 109-115 ◽  
Author(s):  
Xiaotong Wang ◽  
Xiaorui Song ◽  
Tong Wang ◽  
Qihui Zhu ◽  
Guoying Miao ◽  
...  
Keyword(s):  
Crassostrea Gigas ◽  
Pacific Oyster ◽  
Pearl Oyster ◽  
Pinctada Fucata ◽  
Crystal Formation ◽  
Nacreous Layer ◽  
Shell Formation ◽  
Shell Matrix ◽  
The Pacific ◽  
Functional Components

Abstract Mollusc shell matrix proteins (SMPs) are important functional components embedded in the shell and play a role in shell formation. A SMP (Pif177) was identified previously from the nacreous layer of the Japanese pearl oyster Pinctada fucata, and its cleavage products (named pfPif97 and pfPif80 proteins) were found to bind to the chitin framework and induce aragonite crystal formation and orient the c axis. In this study, a homologue of pfPif177 was cloned from the mantle of the Pacific oyster Crassostrea gigas, containing the homologue of pfPif97 only and not pfPif80. This finding hints at the large divergence in gene structure between the two species. This homologue (cgPif97) shares characteristics with pfPif97, and suggests that the biological functions of these two proteins may be similar. The expression pattern of cgPif97 in different tissues and development stages indicates that it may play an important role in shell formation of the adult oyster. The morphology of the inner shell surface was affected by injected siRNA of cgPif97 and the calcite laths of the shell became thinner and narrower when the siRNA dose increased, suggesting that the cgPif97 gene plays an important role in calcite shell formation in C. gigas. In conclusion, we found evidence that the Pif177 gene evolved very fast but still retains a similar function among species.

scholarly journals Molecular Cloning and Characterization of Full-Length cDNA of Calmodulin Gene from Pacific OysterCrassostrea gigas

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Xing-Xia Li ◽  
Wen-Chao Yu ◽  
Zhong-Qiang Cai ◽  
Cheng He ◽  
Na Wei ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Pacific Oyster ◽  
Pearl Oyster ◽  
Full Length ◽  
Pinctada Fucata ◽  
Whole Genome Sequence ◽  
Formation Mechanisms ◽  
Shell Formation ◽  
Full Length Cdna ◽  
Ef Hand

The shell of the pearl oyster (Pinctada fucata) mainly comprises aragonite whereas that of the Pacific oyster (Crassostrea gigas) is mainly calcite, thereby suggesting the different mechanisms of shell formation between above two mollusks. Calmodulin (CaM) is an important gene for regulating the uptake, transport, and secretion of calcium during the process of shell formation in pearl oyster. It is interesting to characterize the CaM in oysters, which could facilitate the understanding of the different shell formation mechanisms among mollusks. We cloned the full-length cDNA of Pacific oyster CaM (cgCaM) and found that the cgCaM ORF encoded a peptide of 113 amino acids containing three EF-hand calcium-binding domains, its expression level was highest in the mantle, hinting that the cgCaM gene is probably involved in shell formation of Pacific oyster, and the common ancestor of Gastropoda and Bivalvia may possess at least three CaM genes. We also found that the numbers of some EF hand family members in highly calcified species were higher than those in lowly calcified species and the numbers of these motifs in oyster genome were the highest among the mollusk species with whole genome sequence, further hinting the correlation between CaM and biomineralization.

Novel Proteins from the Calcifying Shell Matrix of the Pacific Oyster Crassostrea gigas

2011 ◽  
Vol 13 (6) ◽  
pp. 1159-1168 ◽  
Author(s):  
Benjamin Marie ◽  
Isabelle Zanella-Cléon ◽  
Nathalie Guichard ◽  
Michel Becchi ◽  
Frédéric Marin
Keyword(s):  
Crassostrea Gigas ◽  
Pacific Oyster ◽  
Novel Proteins ◽  
Shell Matrix ◽  
The Pacific

scholarly journals A cDNA Cloning of a Novel Alpha-Class Tyrosinase of Pinctada fucata: Its Expression Analysis and Characterization of the Expressed Protein

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ryousuke Takgi ◽  
Tomoyuki Miyashita
Keyword(s):  
Signal Sequence ◽  
Expression System ◽  
Pearl Oyster ◽  
Pinctada Fucata ◽  
High Yield ◽  
Pcr Analysis ◽  
Nacreous Layer ◽  
Copper Binding ◽  
Copper Proteins ◽  
Shell Matrix

Tyrosinase plays an important role in the formation of the shell matrix and melanin synthesis in mollusks shells. A cDNA clone encoding a 47 kDa protein was isolated from the pearl oyster Pinctada fucata. The cDNA was 1,957 base pairs long and encodes a 417 residue protein that has extensive sequence identity with tyrosinase (polyphenol oxidase: EC 1.14.18.1). This tyrosinase-like protein, termed PfTy, contains an N-terminal signal sequence and the two copper-binding domain signatures (CuA and CuB), suggesting that PfTy belongs to the α-subclass of type-3 copper proteins. Enzyme activity of PfTy was examined by a spectrophotometric method using the translation product derived from an S30 T7 high-yield protein expression system. Tyrosinase activity was seen in this recombinant product. RT-PCR analysis showed that PfTy mRNA was expressed in the mantle pallial, but not in the mantle edge. Therefore, PfTy may participate in insoluble shell matrix formation of the nacreous layer. PfTy expression was also observed in the foot, liver, and adductor muscle, suggesting that PfTy participates in the synthesis of melanins, which are effective scavengers of free radicals formed in multiple intracellular oxidative processes. This is the first report of a novel α-class tyrosinase from the pearl oyster P. fucata.

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