Study of the onset of puberty in the European sea bass

Pubertal development in males starts with the onset of spermatogenesis that implies the division of primary spermatogonia and their subsequent entry into meiosis. Whole genome microarray expression profile was used as a means to explore the molecular basis underlying the onset of pubertal development in sea bass. The present study is aimed at the characterization of the expression of genes involved in the onset of spermatogenesis in the European sea bass. The study is focused on the first stages of the process including the appearance of spermatocytes and thus the first meiotic divisions. The transcriptomic study using a sea bass-specific microarray resulted in a number of genes differentially expressed during the onset of spermatogenesis. Among those, genes involved in cell-cycle progression, microtubule assembly during meiosis or retinoic acid signaling pathway indicating that they can be used as potential molecular markers for the onset of spermatogenesis in sea bass. Two different experimental groups (conditions) were used in the study. Condition 1 corresponded to testicular development stage I, whereas condition 2 represented testicular development stage II. Both conditions were compared to reveal differences in gene expression signatures related to the onset of spermatogenesis.