Characterization, expression and functional analysis of CYP306a1 in the oriental river prawn, Macrobrachium nipponense

The CYP306a1 gene is a member of the Halloween genes in the cytochrome P450 supergene family, which play an important regulatory role in the synthesis of 20-hydroxyecdysone (20E) in arthropods. In this study, we cloned the full-length DNA sequence of the CYP306a1 (Mn-CYP306a1) gene in the oriental river prawn Macrobrachium nipponense. The sequence encoded 600 amino acids, including typical CYP450 conserved domains. We detected the expression of Mn-CYP306a1 in different tissues of male and female M. nipponense by qRT-PCR. The results showed that the gene was highly expressed in its respective gonadal tissues (ovary and testis). MnCYP306a1 was expressed in embryonic and metamorphic developmental stages, and the expression trend appeared in a wave pattern, firstly rising gradually, with peaks appearing in the L1 gastrulation stage and later at the PL10 and PL25 metamorphic stages. RNA interference (RNAi) experiments have found that Mn-CYP306a1 dsRNA can effectively reduce the content of 20E and the molting frequency of M. nipponense. The molting frequency of the experimental group was almost half that of the control group. Moreover, the body weight of M. nipponense was also significantly negatively affected in the late stage of the RNAi experiment. This study showed that Mn-CYP306a1 played an important role in promoting 20E synthesis in M. nipponense.