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.

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 Transcriptional regulation of the matrix protein Shematrin-2 during shell formation in pearl oyster

2018 ◽  
Vol 293 (46) ◽  
pp. 17803-17816 ◽  
Author(s):  
Yan Chen ◽  
Jing Gao ◽  
Jun Xie ◽  
Jian Liang ◽  
Guilan Zheng ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Transcription Factors ◽  
Calcium Carbonate ◽  
Matrix Protein ◽  
Pearl Oyster ◽  
Pinctada Fucata ◽  
Functional Assay ◽  
Shell Formation ◽  
Molluscan Shell ◽  
The Matrix

The molluscan shell is a fascinating biomineral consisting of a highly organized calcium carbonate composite. Biomineralization is elaborately controlled and involves several macromolecules, especially matrix proteins, but little is known about the regulatory mechanisms. The matrix protein Shematrin-2, expression of which peaks in the mantle tissues and in the shell components of the pearl oyster Pinctada fucata, has been suggested to be a key participant in biomineralization. Here, we expressed and purified Shematrin-2 from P. fucata and explored its function and transcriptional regulation. An in vitro functional assay revealed that Shematrin-2 binds the calcite, aragonite, and chitin components of the shell, decreases the rate of calcium carbonate deposition, and changes the morphology of the deposited crystal in the calcite crystallization system. Furthermore, we cloned the Shematrin-2 gene promoter, and analysis of its sequence revealed putative binding sites for the transcription factors CCAAT enhancer–binding proteins (Pf-C/EBPs) and nuclear factor-Y (NF-Y). Using transient co-transfection and reporter gene assays, we found that cloned and recombinantly expressed Pf-C/EBP-A and Pf-C/EBP-B greatly and dose-dependently up-regulate the promoter activity of the Shematrin-2 gene. Importantly, Pf-C/EBP-A and Pf-C/EBP-B knockdowns decreased Shematrin-2 gene expression and induced changes in the inner-surface structures in prismatic layers that were similar to those of antibody-based Shematrin-2 inhibition. Altogether, our data reveal that the transcription factors Pf-C/EBP-A and Pf-C/EBP-B up-regulate the expression of the matrix protein Shematrin-2 during shell formation in P. fucata, improving our understanding of the transcriptional regulation of molluscan shell development at the molecular level.

Characterization of organic matrix components of pearl oyster, Pinctada fucata and their implications in shell formation

2008 ◽  
Vol 2 (2) ◽  
pp. 156-161 ◽  
Author(s):  
Chihiro Nogawa ◽  
Mami Obara ◽  
Megumi Ozawa ◽  
Aya Sato ◽  
Akiko Watanabe ◽  
...  
Keyword(s):  
Organic Matrix ◽  
Pearl Oyster ◽  
Pinctada Fucata ◽  
Shell Formation ◽  
Matrix Components

A novel extracellular EF-hand protein involved in the shell formation of pearl oyster

2007 ◽  
Vol 1770 (7) ◽  
pp. 1037-1044 ◽  
Author(s):  
Jing Huang ◽  
Cen Zhang ◽  
Zhuojun Ma ◽  
Liping Xie ◽  
Rongqing Zhang
Keyword(s):  
Pearl Oyster ◽  
Shell Formation ◽  
Ef Hand
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