siRNA-Mediated MrIAG Silencing Induces Sex Reversal in Macrobrachium rosenbergii

Abstract

The insulin-like androgenic gland (IAG) gene is well known in male crustacean, and it is a key regulator in male sexual differentiation and maintaining the male sexual characteristic. The neo-female can be produced by silencing the MrIAG (Macrobrachium rosenbergii Insulin-like Androgenic Gland) in male Macrobrachium rosenbergii. This is the first time to use siRNA approach to silenced MrIAG in male M. rosenbergii. In the current study, the optimal injection dosage to achieve sex reversal is 0.5 μg/g body weight. After MrIAG silencing, the expression level of Dmrt11e, Dmrt99b, MRPINK, Mrr, Sxl1, and Sxl2 decreased significantly. As their long-term silencing effect of MrIAG, the dsRNA and siRNA approaches produce three and two individual neo-females, respectively. The neo-female has a wider brood chamber, ovipositing setae, and ovigerous setae, which is resembled normal female. After a long-term silencing with siRNA, most of the germ cells were arrested in spermatocytes stage, but the spermatocytes in control can further developed into spermatozoon. The seminiferous tubules are loosely arranged and the spermatocytes are more than spermatozoon in the 0.5 μg/g body weight treatment dose. This current study suggests a new path to obtain neo-females through siRNA silencing.