Plasma Membrane Calcium ATPase (PMCA) plays a critical role in transporting Ca<sup>2+</sup> out of the cytosol across the plasma membrane. Here, a full-length cDNA sequence of plasma membrane Ca<sup>...Plasma Membrane Calcium ATPase (PMCA) plays a critical role in transporting Ca<sup>2+</sup> out of the cytosol across the plasma membrane. Here, a full-length cDNA sequence of plasma membrane Ca<sup>2+</sup>-ATPase gene was isolated from the gill of <em>Hyriopsis cumingii</em> (HcPMCA) by using SMART RACE technique. The entire cDNA was 5230 bp, including a 417-bp 5'-UTR, a 3588-bp ORF and a 1225-bp 3'-UTR, encoding a 1195-amino acid protein, and no putative signal peptide was predicted. Compared with PMCA homologs from seawater mollusks, HcPMCA had high similarity with them in both sequence and structure. Tissue-specific expression analysis revealed that HcPMCA mRNA was detected in all the sampled tissues, but was prominently expressed in the gill and mantle. When exposed to a serie of increasing Ca<sup>2+</sup> that lasted for 7 days, the mRNA expression of HcPMCA in the mantle was slightly downregulated, but peaked at 60 mg/L. Moreover, the temporal expression of HcPMCA transcripts in the mantle after 60 mg/L Ca<sup>2+</sup> exposure was shown to be bell-shaped, which was slightly downregulated at 24 h, but upregulated from 24 h to 48 h post-treatment, peaking at 48 h. The result of present study provides useful information for further studies on function and regulation mechanism of HcPMCA gene.展开更多
In triangle sail mussel(Hyriopsis cumingii),shell biomineralization is a complicated process that involves multiple gene products.Shell matrix proteins are involved in the formation of the organic framework and play a...In triangle sail mussel(Hyriopsis cumingii),shell biomineralization is a complicated process that involves multiple gene products.Shell matrix proteins are involved in the formation of the organic framework and play an important role in the regulation of calcium carbonate deposition.In this study,A new shell matrix protein gene Hc-transgelin was identified in H.cumingii.The full-length cDNA of Hc-transgelin was 1200 bp,including a 501 bp open reading frame,which encoded 166 amino acids.Hc-transgelin is rich in lysine,it accounts for 11.40%of the protein.The predicted transgelin protein contained a conserved calmodulin homologous domain.A tissue-specific expression assay indicated that Hc-transgelin exhibited significantly highest expression in the mantle.Furthermore,Hc-transgelin in situ hybridization detected positive signals at the edge of the mantle outer fold,where nacre and prismatic layer biomineralization occur.An RNA interference assay showed that the shape of aragonite flakes in nacre changed and their growth was inhibited,and cracks appeared in the prismatic layer organic sheath when the expression of Hc-transgelin was suppressed.In a shell repair assay,a higher expression of Hc-transgelin appeared from day 12 to day 25 when the nacre accumulated quickly.These findings indicate that Hc-transgelin may be involved in the formation of aragonite flakes in the nacre and play a role in the formation of the organic sheath in the prismatic layer of the shell.This study provides new insights into the role of the Hc-transgelin gene and also contributes to the molecular understanding of mollusk shell formation.展开更多
In nature,shells exhibit remarkable high toughness and impact resistance to the external load despite their brittle main constituent and simple hierarchical structure.In this work,the structure of the mussel shell Hyr...In nature,shells exhibit remarkable high toughness and impact resistance to the external load despite their brittle main constituent and simple hierarchical structure.In this work,the structure of the mussel shell Hyriopsis cumingii is analyzed by scanning electron micro scope and atomic force microscope,and the macro/micro compression and impact tests are perfonned.Results show that the shell has a three-layer structure:an outer cuticle layer,a prismatic layer,and a nacreous layer.The stiffer and load-dependent prismatic layer is conducive to improve the impact resistance of shell structure.Fracture morphology after failure proves that cracks are transgranularly propagated inside the prism and aragonite platelet,and the crack deflection and platelet pullout can effectively lock the stress,thereby eventually improving the impact-resistance and toughness of the shell.展开更多
Organic matrix proteins play an important role in the biomineralization of mollusc shells.We have identified and characterized a novel matrix protein,namely hic74,isolated from the mantle of the freshwater mussel Hyri...Organic matrix proteins play an important role in the biomineralization of mollusc shells.We have identified and characterized a novel matrix protein,namely hic74,isolated from the mantle of the freshwater mussel Hyriopsis cumingii.The hic74 gene encodes a 850 amino acid protein that is rich in alanine(ala,30.8%),glycine(gly,25.8%)and serine(ser,10.6%),with ala mainly existing in poly-ala forms within the ala/gly-rich regions.Quantitative PCR expression analysis demonstrated that hic74 was specifically amplified from the mantle and in situ hybridization showed a strong signal in the epithelial cells in the pallial region of the mantle.Lower levels of expression were detected during the early stages of pearl sac formation but increased and remained constant during nacreous layer formation suggesting that hic74 might be involved in this process.展开更多
文摘Plasma Membrane Calcium ATPase (PMCA) plays a critical role in transporting Ca<sup>2+</sup> out of the cytosol across the plasma membrane. Here, a full-length cDNA sequence of plasma membrane Ca<sup>2+</sup>-ATPase gene was isolated from the gill of <em>Hyriopsis cumingii</em> (HcPMCA) by using SMART RACE technique. The entire cDNA was 5230 bp, including a 417-bp 5'-UTR, a 3588-bp ORF and a 1225-bp 3'-UTR, encoding a 1195-amino acid protein, and no putative signal peptide was predicted. Compared with PMCA homologs from seawater mollusks, HcPMCA had high similarity with them in both sequence and structure. Tissue-specific expression analysis revealed that HcPMCA mRNA was detected in all the sampled tissues, but was prominently expressed in the gill and mantle. When exposed to a serie of increasing Ca<sup>2+</sup> that lasted for 7 days, the mRNA expression of HcPMCA in the mantle was slightly downregulated, but peaked at 60 mg/L. Moreover, the temporal expression of HcPMCA transcripts in the mantle after 60 mg/L Ca<sup>2+</sup> exposure was shown to be bell-shaped, which was slightly downregulated at 24 h, but upregulated from 24 h to 48 h post-treatment, peaking at 48 h. The result of present study provides useful information for further studies on function and regulation mechanism of HcPMCA gene.
基金supported by the National Key R&D Program of China (2018YFD0901406)the National Natural Science Foundation of China (31872565)+1 种基金the earmarked fund for CARS (CARS-49)the Sponsored by Program of Shanghai Academic Research Leader (19XD1421500).
文摘In triangle sail mussel(Hyriopsis cumingii),shell biomineralization is a complicated process that involves multiple gene products.Shell matrix proteins are involved in the formation of the organic framework and play an important role in the regulation of calcium carbonate deposition.In this study,A new shell matrix protein gene Hc-transgelin was identified in H.cumingii.The full-length cDNA of Hc-transgelin was 1200 bp,including a 501 bp open reading frame,which encoded 166 amino acids.Hc-transgelin is rich in lysine,it accounts for 11.40%of the protein.The predicted transgelin protein contained a conserved calmodulin homologous domain.A tissue-specific expression assay indicated that Hc-transgelin exhibited significantly highest expression in the mantle.Furthermore,Hc-transgelin in situ hybridization detected positive signals at the edge of the mantle outer fold,where nacre and prismatic layer biomineralization occur.An RNA interference assay showed that the shape of aragonite flakes in nacre changed and their growth was inhibited,and cracks appeared in the prismatic layer organic sheath when the expression of Hc-transgelin was suppressed.In a shell repair assay,a higher expression of Hc-transgelin appeared from day 12 to day 25 when the nacre accumulated quickly.These findings indicate that Hc-transgelin may be involved in the formation of aragonite flakes in the nacre and play a role in the formation of the organic sheath in the prismatic layer of the shell.This study provides new insights into the role of the Hc-transgelin gene and also contributes to the molecular understanding of mollusk shell formation.
基金The authors are grateful for the financial support from the National Defense Innovation Projectthe National Natural Science Foundation of China(No.51801098)+1 种基金the Natural Science General Foundation of Jiangsu Province(No.18KJB130003)the High-level Scientific Research Foundation of Nanjing Institute of Technology(No.YKJ201708).
文摘In nature,shells exhibit remarkable high toughness and impact resistance to the external load despite their brittle main constituent and simple hierarchical structure.In this work,the structure of the mussel shell Hyriopsis cumingii is analyzed by scanning electron micro scope and atomic force microscope,and the macro/micro compression and impact tests are perfonned.Results show that the shell has a three-layer structure:an outer cuticle layer,a prismatic layer,and a nacreous layer.The stiffer and load-dependent prismatic layer is conducive to improve the impact resistance of shell structure.Fracture morphology after failure proves that cracks are transgranularly propagated inside the prism and aragonite platelet,and the crack deflection and platelet pullout can effectively lock the stress,thereby eventually improving the impact-resistance and toughness of the shell.
基金This work was supported by the National Science and Technology Support Program(2012BAD26B04)the National Natural Science Foundation of China(31272657)Shanghai Collaborative Innovation Center for Aquatic Animal Genetics and Breeding(ZF1206).
文摘Organic matrix proteins play an important role in the biomineralization of mollusc shells.We have identified and characterized a novel matrix protein,namely hic74,isolated from the mantle of the freshwater mussel Hyriopsis cumingii.The hic74 gene encodes a 850 amino acid protein that is rich in alanine(ala,30.8%),glycine(gly,25.8%)and serine(ser,10.6%),with ala mainly existing in poly-ala forms within the ala/gly-rich regions.Quantitative PCR expression analysis demonstrated that hic74 was specifically amplified from the mantle and in situ hybridization showed a strong signal in the epithelial cells in the pallial region of the mantle.Lower levels of expression were detected during the early stages of pearl sac formation but increased and remained constant during nacreous layer formation suggesting that hic74 might be involved in this process.
