To reveal molecular mechanism of how polychaetes enhanced reproductive maturation in the male black tiger shrimp (Penaeus monodon), transcriptomic profiles of male reproductive organs (testes and vas deferens) between polychaete-fed and commercial pellet-fed male brooders were compared using cDNA microarray. The overall profiles were distinguishingly different between the two feed groups as well as between testes and vas deferens. Additionally, six of 11 differentially expressed gene identified by the microarray (HNRPUL1 and GCP4 in testes, MAT2B, CDC16, and CSN5 in vas deferens, and SLD5 in both organs) were validated by quantitative real-time PCR (qPCR) and found to exhibit significantly higher expression levels in polychaete-fed shrimp than those in commercial pellet-fed shrimp. From microarray and qPCR results, the differentially expressed transcripts in both testes and vas deferens between different feeds belonged to DNA replication and microtubule nucleation pathways. Interestingly, while the transcripts involved in nutrient uptake and nucleotide biosynthesis were increased only in testes, those involved in protein refolding and apoptosis were increased only in vas deferens. These findings suggest that polychaetes may enhance spermatogenesis by increasing spermatogonia proliferation in testes and by regulating mature spermatozoa in vas deferens.
Keywords: Penaeus monodon; Polychaetes; Quantitative real-time PCR; Testes; Vas deferens; cDNA microarray.