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Abstract Background The eastern oyster, Crassostrea virginica (Gmelin 1791), is an economically important species cultured in many areas in North America. It is also ecologically important because of the impact of its filter feeding behaviour on water quality. Populations of C. virginica have been threatened by overfishing, habitat degradation, and diseases. Through genome research, strategies are being developed to reverse its population decline. However, large-scale expressed sequence tag (EST) resources have been lacking for this species. Efficient generation of EST resources from this species has been hindered by a high redundancy of transcripts. The objectives of this study were to construct a normalized cDNA library for efficient EST analysis, to generate thousands of ESTs, and to analyze the ESTs for microsatellites and potential single nucleotide polymorphisms (SNPs). Results A normalized and subtracted C. virginica cDNA library was constructed from pooled RNA isolated from hemocytes, mantle, gill, gonad and digestive tract, muscle, and a whole juvenile oyster. A total of 6,528 clones were sequenced from this library generating 5,542 high-quality EST sequences. Cluster analysis indicated the presence of 635 contigs and 4,053 singletons, generating a total of 4,688 unique sequences. About 46% (2,174) of the unique ESTs had significant hits (E-value ≤ 1e-05) to the non-redundant protein database; 1,104 of which were annotated using Gene Ontology (GO) terms. A total of 35 microsatellites were identified from the ESTs, with 18 having sufficient flanking sequences for primer design. A total of 6,533 putative SNPs were also identified using all existing and the newly generated EST resources of the eastern oysters. Conclusion A high quality normalized cDNA library was constructed. A total of 5,542 ESTs were generated representing 4,688 unique sequences. Putative microsatellite and SNP markers were identified. These genome resources provide the material basis for future microarray development, marker validation, and genetic linkage and QTL analysis.

The effects of high hydrostatic pressure (HHP) processing at 200 MPa, 400 MPa, and 600 MPa on the proximate composition, inactivation of bacteria, and color of the red claw crayfish Cherax quadricarinatus were evaluated. High hydrostatic pressure processing resulted in complete shelling and a significant decrease in the moisture content (P < 0.05), whereas no significant differences were observed in the content of ash, crude protein, and crude lipid, except for the crude lipid content between 200 MPa and 600 MPa groups (P < 0.05). After pressurization, the Escherichia coli, Vibrio vulnificus, and Vibrio parahaemolyticus counts decreased significantly with the increase of pressure, even to an undetected level for V. vulnificus and V. parahaemolyticus at 400 and 600 MPa (P < 0.05), respectively. During 30-d storage at 4[degrees]C and -20[degrees]C, the counts of these three bacterial species increased significantly with increased storage time and temperature. After HHP processing, a* value changed substantially, whereas L* and b* values had little change for meat. The total color difference ([DELTA]E*) suggested that the HHP-treated red claw crayfish exhibited very distinctive or substantial differences compared with fresh individuals. KEY WORDS: red claw crayfish, Cherax quadricarinatus, high hydrostatic pressure processing, shelling, bacterial counts, INTRODUCTION The red claw crayfish Cherax quadricarinatus is a native freshwater crayfish inhabiting northeastern Queensland, northern Australia, and southeastern Papua New Guinea (Saoud et al. 2013, Yuan et al. 2019). [...]

Nowadays, amine containing electrode interface material destroy the non‐fullerene acceptor becomes a hard nut to crack for organic solar cells. Developing water‐soluble interface material which is no chemical reaction with non‐fullerene acceptor is an important research theme. Here, we report two bi‐triangular pyramidal electronic configuration organic‐phosphonium bromides as non‐amine cathode interfacial layer for fabricating high‐efficiency stable organic solar cells. The power conversion efficiency (PCE) of inverted device structure with PBDB‐T/ITIC as active layer is up to 11.58 % which is great larger than control device PCE (9.35 %). Same device structure with PM6/Y6 as active layer, the PCE is up to 15.26 % and also is dramatically higher than the referred device PCE 14.36 %. Meanwhile, the devices show greatly improved stability by organic‐phosphonium bromide interlayer. [ABSTRACT FROM AUTHOR]

ABSTRACT The pearl oyster Pinctada fucata martensii is the dominant species for production of marine pearls in China. To explore the relative contributions of donor and host oysters to nacre [...]

ABSTRACT Large numbers of genetic markers are needed for genomic analyses in the eastern oyster (Crassostrea virginica). We previously identified 53 simple sequence repeat (SSR) markers from an expressed sequence [...]

Abstract: This study aimed to investigate the correlation between marker polymorphism and growth traits in Pinctada fucata martensii. Five microsatellite markers (2PM206, 3PM10, 4PM34, 4PM50, and PM6) derived from expressed sequence tags were selected and were applied in a total of 339 pearl oysters. Observed heterozygosity and expected heterozygosity of the five microsatellite loci ranged from 0.360 to 0.681 and 0.429 to 0.672, respectively. Four loci (2PM206, 4PM34, 4PM50, and PM6) deviated from Hardy–Weinberg equilibrium (P > 0.05). Four growth traits, including shell height (SH), shell length (SL), shell width, and total weight (TW) were measured in all 339 samples. After Bonferroni correction, markers 2PM206, 4PM34, and 4PM50 were correlated with all four growth traits. Marker PM6 was significantly correlated with SH, SL, and TW, and marker 3PM10 was associated with SH and SL traits (P < 0.05). These results provide useful information for marker‐assisted breeding programs in P. fucata martensii. [ABSTRACT FROM AUTHOR]

Pinctada fucata martensii is an ideal animal for study of biomineralization. Although dozens of genes have been identified, the molecular mechanism of biomineralization remains still unclear. The purpose here was to discover the expression profiles of nine biomineralization genes in related tissues: mantle edge ( ME), mantle centre ( MC) and pearl sac ( PS), and to explore the relationships between expression level and nacre thickness. The expression levels of seven genes ( ACCBP, aspein, CaM, EFCBP, KRMP, nacrein and prismalin-14) showed no significant difference between ME and MC, but were significantly higher than those in PS. The expression level of N19 was the same in ME and PS, significantly higher than that in MC. However, msi60 in ME, MC and PS showed no significant differences in expression level. In addition, the correlations of expression levels between ME, MC and PS were highly significant, indicating that there are some similar function and mechanism among the three tissues. Also the nine genes had significant correlation of expression levels between one another. Furthermore, no other genes from oysters which produced pearls of different grades showed significant difference in the expression level, except CaM in MC, which had significantly higher expression level in the medium pearl grade than in the plain nucleus grade. Moreover, the expression level of msi60 in MC of host oyster was significantly correlated with produced pearl layer thickness, suggesting that msi60 might play an important role in pearl formation and host oyster may also participate in the development of pearl. [ABSTRACT FROM AUTHOR]