Characterization of water microbiota and their relationship with resident oysters during an oyster mortality event.

Microorganisms are vital for the health of marine invertebrates, and their assembly is driven by both deterministic and stochastic factors that regulate residents (innate to the host) and transients (from ambient water). However, the role of water microbiota and the significance of deterministic and stochastic processes in aquatic hosts facing mortality threats are largely unknown. This study examines the shifts in water microbiota during an oyster mortality event using amplicon sequencing and compared with those of resident oysters to disentangle the balance of the deterministic and stochastic factors involved.

Easy-to-Use CRISPR-Cas9 Genome Editing in the Cultured Pacific Abalone ().

The Pacific abalone is an important aquaculture shellfish and serves as an important model in basic biology study. However, the study of abalone is limited by lack of highly efficient and easy-to-use gene-editing tools. In this paper, we demonstrate efficient gene knockout in Pacific abalone using CRISPR-Cas9.

Host-microbiota interactions play a crucial role in oyster adaptation to rising seawater temperature in summer.

Climate change, represented by rising and fluctuating temperature, induces systematic changes in marine organisms and in their bacterial symbionts. However, the role of host-microbiota interactions in the host's response to rising temperature and the underlying mechanisms are incompletely understood in marine organisms. Here, the symbiotic intestinal microbiota and transcriptional responses between diploid and triploid oysters that displayed susceptible and resistant performance under the stress of rising temperature during a summer mortality event were compared to investigate the host-microbiota interactions.

Integrated application of transcriptomics and metabolomics provides insights into condition index difference mechanisms in the Pacific oyster (Crassostrea gigas).

The condition index (CI) is an economically important tool for assessing the quality of oysters, such as the Pacific oyster Crassostrea gigas. However, little is known about the mechanisms that underlie differences in CI between different C. gigas populations.

Comparative and evolutionary analyses reveal conservation and divergence of the notch pathway in lophotrochozoa.

Lophotrochozoan species exhibit wide morphological diversity; however, the molecular basis underlying this diversity remains unclear. Here, we explored the evolution of Notch pathway genes across 37 metazoan species via phylogenetic and molecular evolutionary studies with emphasis on the lophotrochozoans. We displayed the components of Notch pathway in metazoans and found that Delta and Hes/Hey-related genes, as well as their functional domains, are duplicated in lophotrochozoans.

Characterization of Free Fatty Acid Receptor 4 and Its Involvement in Nutritional Control and Immune Response in Pacific Oysters ().

Free fatty acid receptor 4 (FFAR4) has various physiological functions, including energy regulation and immunological homeostasis. We examined the only FFAR4 homologue in the Pacific oyster (), which functions as a sensor of long-chain fatty acids. is 1098 bp long and contains a seven-transmembrane G protein-coupled receptor domain.

Effects of Bacillus lincheniformis feeding frequency on the growth, digestion and immunity of Haliotis discus hannai.

To study the effects of Bacillus lincheniformis feeding frequency on the survival and growth of Haliotis discus hannai abalone, we measured the expression levels of nonspecific immune genes and monitored the anti-Vibrio parahaemolyticus immune reaction. H. discus hannai (shell length: 32.

Effects of the probiotic Bacillus amyloliquefaciens on the growth, immunity, and disease resistance of Haliotis discus hannai.

The effects of a diet containing the probiotic Bacillus amyloliquefaciens on the survival and growth of Haliotis discus hannai were evaluated by measuring growth and hematological parameters and the expression levels of nonspecific immune genes. In addition, the abalone's response to Vibrio parahaemolyticus infection was assessed. H.

Divergence and plasticity shape adaptive potential of the Pacific oyster.

The interplay between divergence and phenotypic plasticity is critical to our understanding of a species' adaptive potential under rapid climate changes. We investigated divergence and plasticity in natural populations of the Pacific oyster Crassostrea gigas with a congeneric oyster Crassostrea angulata from southern China used as an outgroup. Genome re-sequencing of 371 oysters revealed unexpected genetic divergence in a small area that coincided with phenotypic divergence in growth, physiology, heat tolerance and gene expression across environmental gradients.

The effects of feeding Lactobacillus pentosus on growth, immunity, and disease resistance in Haliotis discus hannai Ino.

To study the effects of probiotic-added food on the survival and growth of abalone (Haliotis discus hannai Ino), the expression levels of nonspecific immune genes and the anti-Vibrio parahaemolyticus infection were examined. During an 8-week culturing experiment in an indoor aquarium and a 2-week V. parahaemolyticus artificial infection experiment, the control group was fed with untreated food once a day, while the experimental groups (L1, L2 and L3) were fed with Lactobacillus pentosus added food.

Effects of a probiotic (Bacillus licheniformis) on the growth, immunity, and disease resistance of Haliotis discus hannai Ino.

To study the effects of a probiotic (Bacillus lincheniformis) on the survival and growth of Haliotis discus hannai Ino, the expression levels of nonspecific immune genes and the resistance to Vibrio parahaemolyticus infection were assessed. Abalones (shell length: 27.64 ± 1.

Genome-wide and single-base resolution DNA methylomes of the Pacific oyster Crassostrea gigas provide insight into the evolution of invertebrate CpG methylation.

Background: Studies of DNA methylomes in a wide range of eukaryotes have revealed both conserved and divergent characteristics of DNA methylation among phylogenetic groups. However, data on invertebrates particularly molluscs are limited, which hinders our understanding of the evolution of DNA methylation in metazoa. The sequencing of the Pacific oyster Crassostrea gigas genome provides an opportunity for genome-wide profiling of DNA methylation in this model mollusc.

Molecular characterization of a mollusk chicken-type lysozyme gene from Haliotis discus hannai Ino, and the antimicrobial activity of its recombinant protein.

A chicken-type lysozyme was obtained and characterized from the abalone Haliotis discus hannai Ino (HdLysC). The full-length cDNA of HdLysC was 586 bp, and it contained an open reading frame of 441 bp, encoding a 147-amino acid protein with a calculated molecular mass of 15.64 kDa and an isoelectric point of 4.

Development of gene-targeted SNP markers for genomic mapping in Pacific abalone Haliotis discus hannai Ino.

Useful and novel DNA markers are needed for aquaculture genetics and breeding. In this study, we report the discovery and development of gene-targeted single nucleotide polymorphisms (SNPs) for genomic mapping in the Pacific abalone Haliotis discus hannai Ino. Single EST or EST-contigs from 66 genes that had positive BLASTx matches (E-value ≤ 1e-8) were used for polymerase chain reaction (PCR) amplification.