Ras-related nuclear protein (Ran) is a small GTPase with many functions, such as hydrolysis of GTP, control of cell development, replication of DNA, and RNA transcription. In this study, the cDNA-encoding ) was cloned using expressed sequence tag (EST) analysis and a rapid amplification of cDNA ends (RACE) approach. The full-length cDNA of was 1191 bp, comprising a 5' untranslated region of 218 bp, a 3' untranslated region of 405 bp, and an open reading frame of 648 bp. The deduced protein had 215 amino acid residues with a molecular mass of 24.6 kD, and 7.13 point of theoretical isoelectric. Ran belongs to the P-loop NTPase super family. Ran has a PTZ00132 model that crosses multiple domains. The members of P-loop NTPase super family have extremely conservative nucleotide sequences. Phylogenetic analyses indicate evolution of Ran proteins within the animal kingdom is very conservative, with that of . Quantitative real-time RT-PCR analysis revealed the gene was expressed in testis, ovary, brain, muscle, eyestalk, abdominal nerve, heart and gill tissues. The ovary has the highest level of expression and the eyestalk has the lowest level of expression ( gene expression of ovary is seven-eight times higher than that of testis, and the expression level of gene increased with the development of ovary. After ovulation in ovarian regression period, the expression level of gene was at a low level. After RNA interference (RNAi), expression of gene in an experimental group of adult females was significantly lower than in the control group (<0.05). After RNA interference (RNAi) in the mature female prawns, the expression of gene in experimental group (injected dsRNA solution into the shrimp's pericardial cavity) was significantly lower than in the control group (injected equal amount of DEPC water into the pranw's pericardial cavity) ( gene changes with the development of ovary. The expression of gene increased from the early stage of ovarian development to the mature stage and decreased rapidly after ovulation in the ovary. Expression of in ovarian tissues in the experimental group was also significantly lower than that of control group (<0.05), indicating RNA interference was effective. Expression of vitellogenin was significantly affected by RNA interference, with expression in the experimental group significantly lower than in the control group ( gene plays a regulatory role in expression of the gene is involved in female ovary development.