The expression of the crab Dmrt transcripts was examined in adult tissues by RT–PCR. Equal amounts (500 ng) of each total RNA from seven types of adult tissues were reverse transcribed into first-strand cDNA using M-MLV transcriptase (Takara). Target gene and the reference gene β-actin were amplified with gene-specific primers: DmrtF1 (5′-GGAGAACGAGGTGCGTGAACTTT- 3′) and DmrtR1 (5′-AGACGAGGACGACGGAGAGGTAT-3′); and β-actinF (5′-CGACGGTCAGGTCATCACCA-3′) and β-actinR (5′-ACGTCGCACTTCATGATGGA-3′). The cycling programwas set as follows: 94°C for 30 s, 55°C for 30 s, and 72°C for 1 min, 30 cycles. The PCR products were electrophoresed on 1.2% agarose gel and stained by ethidium bromide. The size and intensity of the PCR products were examined with BioDoc-It Imaging System (UVP).