Searching for immuno-modulatory sequences in sea bass
(Dicentrarchus labrax L.): transcripts analysis from thymus
Alberto Pallavicini1, Elisa Randelli, Martina Modonut1, Daniela
Casani, Giuseppe Scapigliati, Francesco Buonocore*
Department of Environmental Sciences, University of Tuscia, Largo dell’Università,
01100 Viterbo, Italy
1
Department of Life Sciences, University of Trieste, P.le Valmaura 9, 34143 Trieste,
Italy
*Corresponding author: Dr. Francesco Buonocore, Department of Environmental
Sciences University of Tuscia, Largo dell’Università, I-01100 Viterbo, Italy.
Phone +39-0761-357644; Fax +39-0761-357179; Email: fbuono@unitus.it
ABSTRACT
The thymus is a key organ of the immune system in most vertebrates and, for this
reason, it has been used in this paper for the generation of a normalized cDNA library
from sea bass (Dicentrarchus labrax), one of the most extensively cultured species in
South Mediterranean aquaculture. A total of 1,632 ESTs from this library were
initially analyzed for sequence quality and vector sequences and, after this control,
1,264 (77% of total clones sequenced) high-quality ESTs were further processed. The
total collection of Dicentrarchus labrax thymus ESTs has been deposited in the EBIGenBank-DBJ database (GenBank accession numbers from FN565576 to FN566839).
The functional classification of ESTs was performed by Gene Ontology and KEGG
annotation and, successively, the sequences were analysed using the ImmunomeBase
software to identify potentially immuno related genes. Using this approach, we found
about 100 putative genes involved in immune system responses, most new in sea bass,
that were analysed most in detail. Some of the potentially interesting genes identified
by these in silico analyses were studied by real-time PCR to verify their expression
both at basal level and after in vitro stimulation of sea bass head kidney leukocytes.
The used strategy has been confirmed as a good approach to discovery new immunorelated genes and to improve the knowledge of specific markers that could help the
discrimination of T cell subpopulations in sea bass and, in general, in Teleosts.