Molecular characterization of insulin-like androgenic gland hormone-binding protein gene from the oriental river prawn Macrobrachium nipponense and investigation of its transcriptional relationship with the insulin-like androgenic gland hormone gene

Abstract Insulin-like androgenic gland hormone-binding protein (IAGBP) has been investigated in crustaceans in vitro . However, the relationship between IAGBP and its putative binding protein partner insulin-like androgenic gland hormone (IAG) has not been studied at the transcriptional level in vivo . In the current study, we cloned the full-length cDNA of IAGBP from the oriental river prawn Macrobrachium nipponense ( Mn-IAGBP ) and investigated the transcriptional patterns of Mn-IAGBP and the M. nipponense IAG gene ( Mn-IAG ) at different developmental stages and in different tissues. Mn-IAGBP mRNA was detected in all examined tissues from adult male prawns, with the highest transcriptional levels in the testis. Mn-IAG mRNA was detected in the androgenic gland and hepatopancreas. The genomic sequences of Mn-IAGBP and Mn-IAG were isolated by genome walking and two gene copies were found in both Mn-IAGBP and Mn-IAG . The relationship between Mn-IAGBP and Mn-IAG at the transcriptional level was studied by RNA interference. Injection of Mn-IAGBP double-stranded RNA (dsRNA) significantly reduced the transcription of Mn-IAG , while injection of Mn-IAG dsRNA significantly reduced the transcription of Mn-IAGBP in testis, muscle, androgenic gland, and hepatopancreas. These results demonstrate the involvement of the IAGBP gene in IAG signaling in M. nipponense.