Ecdysone signal pathway participates in shell formation in pearl oysters Pinctada fucata martensii

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.

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Changes in the transcriptional expression of oxidative stress response genes in Akoya pearl oysters (Pinctada fucata) exposed to air and mechanical agitation

Aquaculture ◽

10.1016/j.aquaculture.2012.07.027 ◽

2012 ◽

Vol 362-363 ◽

pp. 33-38 ◽

Cited By ~ 12

Author(s):

Rhiannon P. Kuchel ◽

Sham Nair ◽

David A. Raftos

Keyword(s):

Oxidative Stress ◽

Stress Response ◽

Oxidative Stress Response ◽

Pinctada Fucata ◽

Transcriptional Expression ◽

Mechanical Agitation ◽

Stress Response Genes ◽

Pearl Oysters

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Mass mortality of pearl oyster (Pinctada fucata (Gould)) in Japan in 2019 and 2020 is caused by an unidentified infectious agent

PeerJ ◽

10.7717/peerj.12180 ◽

2021 ◽

Vol 9 ◽

pp. e12180

Author(s):

Tomomasa Matsuyama ◽

Satoshi Miwa ◽

Tohru Mekata ◽

Yuta Matsuura ◽

Tomokazu Takano ◽

...

Keyword(s):

Infectious Agent ◽

Serial Passage ◽

Pearl Oyster ◽

Mass Mortality ◽

Pinctada Fucata ◽

Enveloped Virus ◽

Pearl Oysters ◽

Adult Oyster ◽

Sources Of Infection ◽

Pathogen Occurrence

Mass mortality of 0-year-old pearl oysters, Pinctada fucata (Gould), and anomalies in adults were observed in Japan’s major pearl farming areas in the summer of 2019 and 2020. Although adult oyster mortality was low, both adult and juvenile oysters underwent atrophy of the soft body, detachment of the mantle from nacre (the shiny inner surface of the valves), deposition of brownish material on the nacre, and loss of nacre luster. Infection trials were conducted to verify the involvement of pathogens in this phenomenon. Healthy adult pearl oysters were obtained from areas where this disease had not occurred to use as the recipients. The sources of infection were either affected adult oysters with atrophied soft bodies or batches of juveniles in which mortality had reached conspicuous levels. Transmission of the disease to the healthy oysters were tested either by cohabitation with affected oysters or by injections of the hemolymph of affected animals. The injection infection test examined the effects of filtration and chloroform exposure on the pathogen. Occurrence of the disease was confirmed by the appearance of brown deposits on the nacre and loss of nacre luster. The abnormalities of nacre were clearly reproduced in recipient shells in three out of four cohabitation trials with affected oysters. The disease was also reproduced in six out of six injection trails either with hemolymph filtered through 100 nm filter or with hemolymph treated with chloroform. In a serial passage with hemolymph injections, the disease was successfully transmitted through eight passages. These results suggest that the etiology of the disease is a non-enveloped virus with a diameter ≤100 nm.

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