A newly characterized CFSH gene in sex chromosomes is associated with growth instead of sexual development in the prawn Macrobrachium rosenbergii

Crustacean female sex hormone (CFSH) was first identified as a female eyestalk-specific factor involved in the female sexual development in blue crab. Whether CFSH has conserved role in other decapod species remains to be clarified. In this study, we identified a CFSH gene (MrCFSH) in the Z and W chromosomes from the prawn Macrobrachium rosenbergii genome. The MrCFSH encodes a protein of 306 amino acids, including a signal peptide, a precursor-associated peptide, and a mature peptide. The MrCFSH transcripts was expressed in the brain, heart, and gonads in both female and male adults. During sexual development, the expression of MrCFSH transcripts gradually increased in female and male juveniles from post-larval 10 (PL10) to PL60 stages but no significant difference between the females and males at the same stages were found. To investigate its potential role in early sexual development, in vivo RNAi experiments were performed by injecting MrCFSH dsRNA into juveniles from PL30 to PL90 stages. After two months of administration, the sexual characteristics of the females and males were not affected, but the growth rate of juveniles was significantly inhibited compared to the control group injected with GFP dsRNA. The body length and body weight was reduced by 25%, 35%, 28%, 26%, and 69%, 76%, 65%, 61% in the juveniles at PL120, PL150, PL180 and PL210 stages, respectively. The body length and weight of males at PL210 stage were reduced by 22% and 54%, and those of females were reduced by 26% and 60%, respectively. Overall, our present study revealed that the MrCFSH is associated with growth instead of sexual development in the prawn M. rosenbergii.