Isolation of cDNA, genomic organization and expression of small androgen receptor-interacting protein 1 (PmSARIP1) in the giant tiger shrimp Penaeus monodon

The full-length cDNA and genomic organization of small androgen receptor-interacting protein 1 (SARIP1; also called RWD-containing protein 1, Rwdd1) in the giant tiger shrimp (Penaeus monodon) was isolated and characterized. PmSARIP1 was 1366 bp in length containing an open reading frame (ORF) of 738 bp corresponding to a polypeptide of 245 amino acids. Its genomic sequence contained 5 exons, 4 introns and untranslated regions (UTRs) spanning 5937 bp in length. Tissue distribution analysis indicated that PmSARIP1 was specifically expressed in gonads (ovaries > testes) but not in other tissues of wild P. monodon adults. The expression level of PmSARIP1 was not differentially expressed during ovarian maturation in intact wild adults (P > 0.05). Eyestalk ablation resulted in up-regulation of PmSARIP1 throughout the ovarian maturation of wild adults where the peak level was observed at stage I (previtellogenic) ovaries (P < 0.05). PmSARIP1 mRNA was clearly localized in ooplasm of previtellogenic oocytes. Serotonin injection (5-HT, 50 μg/g body weight; 18-month-old shrimp) promoted the expression level of ovarian PmSARIP1 at 6-72 h post injection (hpi) with the peak level at 12 hpi (P < 0.05). Exogenous progesterone administration (0.1 μg/g BW; 14-month-old shrimp) did not significantly affect the expression level of ovarian PmSARIP1. In contrast, 17β-estradiol treatment (0.01 μg/g BW) resulted in an increase of PmSARIP1 in 14-month-old shrimp at 7 days post injection (dpi). Results from this study suggested that PmSARIP1 should play an important role during ovarian maturation of P. monodon.