Transcriptomic profiling of egg quality in Sea bass (Dicentrarchus labrax) sheds light on genes involved in ubiquitination and translation
Résumé
Variable and low egg quality is a major limiting
factor for the development of efficient aquaculture production.
This stems from limited knowledge on the mechanisms underlying
egg quality in cultured fish. Molecular analyses, such
as transcriptomic studies, are valuable tools to identify the
most important processes modulating egg quality. However,
very few studies have been devoted to this aspect so far.
Within this study, the microarray-based transcriptomic analysis
of eggs (of different quality) of sea bass (Dicentrarchus
labrax) was performed. An Agilent oligo microarray experiment
was performed on labelled mRNA extracted from 16
batches of eggs (each batch obtained from a different female)
of sea bass, in which over 24,000 published probe arrays were
used. We identified 39 differentially expressed genes
exhibiting a differential expression between the groups of
low (fertilization rate < 60 %) and high (fertilization
rate > 60 %) quality. The mRNA levels of eight genes were
further analyzed by quantitative PCR. Seven genes were confirmed
by qPCR to be differentially expressed in eggs of low
and high quality. This study confirmed the importance of
some of the genes already reported to be potential molecular
quality indicators (mainly rnf213 and irf7), but we also found
new genes (mainly usp5, mem-prot, plec, cenpf), which had
not yet been reported to be quality-dependent in fish. These
results suggest the importance of genes involved in several
important processes, such as protein ubiquitination, translation,
DNA repair, and cell structure and architecture; these
probably being the mechanisms that contribute to egg developmental
competence in sea bass.
Mots clés
microarray analysis
foetal development
microarray
genomics
transcriptomics
aquaculture
controlled reproduction
fish
sea bass
développement embryonnaire
qualité des oeufs
poisson
moronidae
bar
dicentrarchus labrax
oeuf de poisson
reproduction
ubiquitination
compétence ovocytaire
ovogenèse
expression des gènes
génomique fonctionnelle
analyse microarray
analyse du transcriptome
contrôle de la reproduction
processus biologique