Transcriptome datasets and histological profiles of critical larval stages in gilthead seabream.

The transcriptome of the seabream larvae farmed in different European commercial hatcheries was analysed during critical larval stages. The complementary data herein presented support the findings reported in the associated research article "Insights into core molecular changes associated with metamorphosis in gilthead seabream larvae across diverse hatcheries". Samples were collected from gilthead seabream () hatcheries in Greece (site Gr), Italy (site It), and France (site Fr).

Core microbiome profiles and their modification by environmental, biological, and rearing factors in aquaculture hatcheries.

16S rRNA gene sequencing and bacteria- and genus-specific quantitative PCR was used to profile microbial communities and their associated functions in water, live feed (microalgae, Artemia, and rotifer), and European sea bass and gilthead sea bream larvae from hatcheries in Greece and Italy. The transfer to larvae of genus containing potential pathogens of fish was more likely with Artemia and rotifer than with microalgae or water, irrespective of geographic location. The presence of potentially pathogenic bacteria (Vibrio and Pseudoalteromonas) in the core microbiota of water, live feed, and fish larvae, the enrichment of different bacterial resistance pathways and biofilm formation, and the overall low beneficial bacteria load during larval ontogeny emphasizes the risk for disease outbreaks.

Quantifying dominant bacterial genera detected in metagenomic data from fish eggs and larvae using genus-specific primers.

The goal of this study was to design genus-specific primers for rapid evaluation of the most abundant bacterial genera identified using amplicon-based sequencing of the 16S rRNA gene in fish-related samples and surrounding water. Efficient genus-specific primers were designed for 11 bacterial genera including Alkalimarinus, Colwellia, Enterovibrio, Marinomonas, Massilia, Oleispira, Phaeobacter, Photobacterium, Polarbacerium, Pseudomonas, and Psychrobium. The specificity of the primers was confirmed by the phylogeny of the sequenced polymerase chain reaction (PCR) amplicons that indicated primers were genus-specific except in the case of Colwellia and Phaeobacter.

Factors Driving Bacterial Microbiota of Eggs from Commercial Hatcheries of European Seabass and Gilthead Seabream.

A comprehensive understanding of how bacterial community abundance changes in fishes during their lifecycle and the role of the microbiota on health and production is still lacking. From this perspective, the egg bacterial communities of two commercially farmed species, the European seabass () and the gilthead seabream (), from different aquaculture sites were compared, and the potential effect of broodstock water microbiota and disinfectants on the egg microbiota was evaluated. Moreover, 16S ribosomal RNA gene sequencing was used to profile the bacterial communities of the eggs and broodstock water from three commercial hatcheries.

Specific Evolution and Gene Family Expansion of Complement 3 and Regulatory Factor H in Fish.

The complement system comprises a large family of plasma proteins that play a central role in innate and adaptive immunity. To better understand the evolution of the complement system in vertebrates and the contribution of complement to fish immunity comprehensive and expression analysis of the gene repertoire was made. Particular attention was given to C3 and the evolutionary related proteins C4 and C5 and to one of the main regulatory factors of C3b, factor H (Cfh).