Characterization of aldehyde dehydrogenases aldh1a2 and aldh1a3 in the european sea bass

10º Congreso de la Asociación Ibérica de Endocrinología Comparada (AIEC) : 10º Congresso da Associação Ibérica de Endocrinologia Comparativa (AIEC), 23-25 September 2015, Castellón.-- 1 page

The aldh1a family is involved in the oxidation of aldehydes in different tissues. Several members of this family are responsible for the synthesis of retinoic acid (RA), known to act as a meiotic stimulating factor in higher vertebrates, but in fish this is yet to be confirmed. The main goal of the study was the molecular characterization of the aldh1a family in the European sea bass, Dicentrarchus labrax. The study reports the isolation and characterization of aldh1a2 and aldh1a3, as well as the identification of both genes in other teleost and non teleost genomes. Their tissue distribution in males and in females was also assessed. In addition, testicular cultures were used to study the effect of exogenous RA and FSH, an endocrine key regulator of germ cell development, on the expression of aldh1a2 and aldh1a3. The study shows that both proteins exhibit the main structural amino acid motifs that define them as active NAD(P)-dependent catalytic enzymes. The phylogenetic and synteny analyses of the proteins confirm that they are different orthologs further supporting that the aldh1 family appeared before the divergence of teleosts from the evolutionary lineage. Tissue-specific mRNA expression in juvenile sea bass showed that aldh1a2 levels were higher than those of aldh1a3. Both mRNAs were ubiquitously expressed in several tissues including testis and ovaries, with a clear preference and female-specific expression for aldh1a3 in gonads and brain. This sex-differential expression in gonads suggests a tight regulation on the oxidation of aldehydes and the subsequent synthesis of RA, pointing at their role in cell proliferation and differentiation during gonadal development. Moreover, the expression in testicular cultures of both aldhs during early stages of maturation was sensitive to exogenous RA and FSH, further suggesting an important role of these enzymes in gonadal maturation and reproduction

Funded by projects Reprosex (AGL2011-28890) and Reprobass (PROMETEOII/2014/051). PM was sponsored by a grant MECE2 (ANT0806)

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