A History of the Cultured Pearl Industry

Nagai, Kiyohito

doi:10.2108/zsj.30.783

Cited by 44 publications

(24 citation statements)

References 23 publications

(20 reference statements)

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“…The Genus Pinctada includes the pearl oysters, such as Pinctada fucata , P. margaritifera , and P. maxima , which are distributed in subtropical and tropical portions of the Indo-Pacific Ocean [ 6 ]. These species have been commercially farmed for pearl production since Kokichi Mikimoto established the pearl culture industry at the end of 19th century, using P. fucata [ 7 ]. Recently, transcriptomics [ 8 , 9 ], proteomics [ 10 – 12 ], and gene knockdown techniques [ 13 – 15 ] have been used to investigate genetic components of shell and pearl biomineralization.…”

Section: Introductionmentioning

confidence: 99%

Bivalve-specific gene expansion in the pearl oyster genome: implications of adaptation to a sessile lifestyle

et al. 2016

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IntroductionBivalve molluscs have flourished in marine environments, and many species constitute important aquatic resources. Recently, whole genome sequences from two bivalves, the pearl oyster, Pinctada fucata, and the Pacific oyster, Crassostrea gigas, have been decoded, making it possible to compare genomic sequences among molluscs, and to explore general and lineage-specific genetic features and trends in bivalves. In order to improve the quality of sequence data for these purposes, we have updated the entire P. fucata genome assembly.ResultsWe present a new genome assembly of the pearl oyster, Pinctada fucata (version 2.0). To update the assembly, we conducted additional sequencing, obtaining accumulated sequence data amounting to 193× the P. fucata genome. Sequence redundancy in contigs that was caused by heterozygosity was removed in silico, which significantly improved subsequent scaffolding. Gene model version 2.0 was generated with the aid of manual gene annotations supplied by the P. fucata research community. Comparison of mollusc and other bilaterian genomes shows that gene arrangements of Hox, ParaHox, and Wnt clusters in the P. fucata genome are similar to those of other molluscs. Like the Pacific oyster, P. fucata possesses many genes involved in environmental responses and in immune defense. Phylogenetic analyses of heat shock protein70 and C1q domain-containing protein families indicate that extensive expansion of genes occurred independently in each lineage. Several gene duplication events prior to the split between the pearl oyster and the Pacific oyster are also evident. In addition, a number of tandem duplications of genes that encode shell matrix proteins are also well characterized in the P. fucata genome.ConclusionsBoth the Pinctada and Crassostrea lineages have expanded specific gene families in a lineage-specific manner. Frequent duplication of genes responsible for shell formation in the P. fucata genome explains the diversity of mollusc shell structures. These duplications reveal dynamic genome evolution to forge the complex physiology that enables bivalves to employ a sessile lifestyle in the intertidal zone.Electronic supplementary materialThe online version of this article (doi:10.1186/s40851-016-0039-2) contains supplementary material, which is available to authorized users.

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Section: Introductionmentioning

confidence: 99%

Bivalve-specific gene expansion in the pearl oyster genome: implications of adaptation to a sessile lifestyle

et al. 2016

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“…The hypothesis that nacre ultrastructure in molluscs depends on environmental temperature at the time of biomineral deposition (Olson et al, 2012) was demonstrated in pen shells (Gilbert et al, 2017). The challenge of controlling the thickness of nacre tablets is at the level of the lustre; indeed, the fine layers of nacre enhance pearls' lustre (Matsui, 1958in Nagai, 2013. A link has been established between lustre and temperature because temperature is lower and lustre higher in the Gambier Archipelago than in the north of the Tuamotu Archipelago .…”

Section: Rotation Speed Is Controlled By Pearl Shapementioning

confidence: 99%

Influence of temperature and pearl rotation on biomineralization in the pearl oyster Pinctada margaritifera

Moullac

Schuck

Chabrier

et al. 2018

Journal of Experimental Biology

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The objective of this study was to observe the impact of temperature on pearl formation using an integrative approach describing the rotation of the pearls, the rate of nacre deposition, the thickness of the aragonite tablets and the biomineralizing potential of the pearl sac tissue though the expression level of some key genes. Fifty pearl oysters were grafted with magnetized nuclei to allow the rotation of the pearls to be described. Four months later, 32 of these pearl oysters were exposed to four temperatures (22, 26, 30 and 34°C) for 2 weeks. Results showed that the rotation speed differed according to the movement direction: pearls with axial movement had a significantly higher rotation speed than those with random movement. Pearl growth rate was influenced by temperature, with a maximum between 26 and 30°C but almost no growth at 34°C. Lastly, among the nine genes implicated in the biomineralization process, only expression was significantly modified by temperature. These results showed that the rotation speed of the pearls was not linked to pearl growth or to the expression profiles of biomineralizing genes targeted in this study. On the basis of our results, we consider that pearl rotation is a more complex process than formerly thought. Mechanisms involved could include a strong environmental forcing in immediate proximity to the pearl. Another implication of our findings is that, in the context of ocean warming, pearl growth and quality can be expected to decrease in pearl oysters exposed to temperatures above 30°C.

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“…The Japanese pearl oyster, Pinctada fucata, is one of the most important molluscan species in the pearl culture industry [9]. Recently, the P. fucata genome database was published in which all major muscle protein genes were annotated [10] [11] [12].…”

Section: Introductionmentioning

confidence: 99%

Troponin T from the Japanese Pearl Oyster <i>Pinctada fucata</i>: Molecular Cloning, Tissue Distribution, Gene Structure, and Interaction Analysis with Tropomyosin

Funabara¹,

Urakawa²,

Ishikawa³

et al. 2020

AJMB

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Troponin (Tn) is composed of three subunits (TnI, TnC and TnT) that bind Ca 2+ and regulate striated muscle contraction in vertebrates. TnT's function has been extensively described in vertebrates, but its role has been obscure in molluscan muscles. Our previous work indicated that the TnC and TnI subunits work in adductor phasic muscle, but not in catch muscle. Here, we have characterized TnT from the Japanese bivalve pearl oyster Pinctada fucata to start to explain the function of Tn in molluscan muscle contraction. We determined the primary structure of the full-length TnT protein from the P. fucata adductor muscle (Pifuc-TnT), and found that it is composed of 316 amino acid residues with a predicted molecular mass of 37.4 kDa. Multiple sequence alignment showed that Pifuc-TnT has an extension of >60 residues at the C-terminus that are not present in vertebrate TnTs, including known TnTs from other mollusks. Pifuc-TnT gene structure predictions using Splign alignment of the cDNA generated in this study and genome sequences indicated that Pifuc-TnT consists of 13 exons. Start and stop codons are located in exons 2 and 12, respectively. Quantitative real-time PCR revealed that the Pifuc-TnT gene was predominantly expressed in adductor phasic muscle, weakly in adductor catch muscle, slightly in gill, and not at all in mantle and foot. These findings suggest that TnT plays a regulatory role in adductor phasic muscle contraction, but not in catch contraction. Isothermal titration calorimetry revealed that unlike vertebrate TnTs, Pifuc-TnT does not interact with P. fucata tropomyosin-1 nor with tropomyosin-2. These findings in P. fucata imply that Tn functions differently in molluscan muscle than it does in vertebrates.

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A History of the Cultured Pearl Industry

Cited by 44 publications

References 23 publications

Bivalve-specific gene expansion in the pearl oyster genome: implications of adaptation to a sessile lifestyle

Bivalve-specific gene expansion in the pearl oyster genome: implications of adaptation to a sessile lifestyle

Influence of temperature and pearl rotation on biomineralization in the pearl oyster Pinctada margaritifera

Troponin T from the Japanese Pearl Oyster <i>Pinctada fucata</i>: Molecular Cloning, Tissue Distribution, Gene Structure, and Interaction Analysis with Tropomyosin

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A History of the Cultured Pearl Industry

Cited by 44 publications

References 23 publications

Bivalve-specific gene expansion in the pearl oyster genome: implications of adaptation to a sessile lifestyle

Bivalve-specific gene expansion in the pearl oyster genome: implications of adaptation to a sessile lifestyle

Influence of temperature and pearl rotation on biomineralization in the pearl oyster Pinctada margaritifera

Troponin T from the Japanese Pearl Oyster &lt;i&gt;Pinctada fucata&lt;/i&gt;: Molecular Cloning, Tissue Distribution, Gene Structure, and Interaction Analysis with Tropomyosin

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Troponin T from the Japanese Pearl Oyster <i>Pinctada fucata</i>: Molecular Cloning, Tissue Distribution, Gene Structure, and Interaction Analysis with Tropomyosin