sox9 gene expression during stages of larval development and gonadal maturation in the beluga (Huso huso)

sox9 is a protein coding gene that plays a crucial role in the regulation of several cellular activities among vertebrates. According to the importance of the beluga as the main species in aquaculture and the importance of sox9 gene in vertebrate evolution, in this study, the identification of gene sequence and expression pattern in different stages of larval and gonadal development of male beluga was developed. The results showed that the sox9 sequence in the beluga has high homology with the sox9 sequence in other vertebrates, which represents a fundamental role of this gene in different animals. Indeed, the study of sox9 gene expression during larval development (1, 3, 6, 15 and 50 days post hatching- dph) revealed that sox9 mRNA is expressed at different stages of larval and the most expression is about 15 dph. However, in differentiated gonads (developmental stages 1-4), sox9 mRNA expressed only at stage 4. In conclusion, it seems that the sox9 expression is related with cartilage synthesis and organogenesis at early life stages and with testicular development at advanced stages of sexual maturation.