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Three generations of cultured prawn without W chromosome
- Shpak, Nir, Manor, Rivka, Aflalo, Eliahu D., Sagi, Amir
- Aquaculture 2017 v.467 pp. 41-48
- Macrobrachium rosenbergii, RNA interference, W chromosome, aquaculture, biotechnology, double-stranded RNA, females, genes, male reproductive system, males, meta-analysis, population structure, progeny, reproductive performance, shrimp
- The recent introduction into aquaculture of RNA interference (RNAi) for producing the preferred all-male monosex cultures, which give improved yields, has raised awareness of the need to investigate the consequences of such novel biotechnological manipulations. Here, we present meta-analysis style study on data from observations of three consecutive cultured all-male (ZZ) generations of the giant freshwater prawn Macrobrachium rosenbergii (De Man). Each consecutive generation comprised the progeny of RNAi-manipulated sex-reversed males. The manipulation was achieved through the administration of dsRNA encoding the insulin-like androgenic hormone into males (which transformed them into ‘neofemales,’ ZZ) of the previous all-male generation. Each generation was cultured in a separate earthen pond for a short (~4–5months) growout period. At harvest of each of the generations, the typical M. rosenbergii population structure comprising three male morphotypes was obtained. An anatomical examination of the male reproductive system of a representative specimen of the third all-male generation showed normal reproductive outputs, even though the prawns had been grown without the presence of females (WZ) for three generations. At the molecular level, expression of vital male-specific genes in the third generation of all-male M. rosenbergii culture was demonstrated. Thus, the present study showing the lack of any overtly apparent long-term consequences of the RNAi-based biotechnology provides support for the responsible use of temporal RNAi in aquaculture. Finally, the absence of the W chromosome for three generations raises questions with regard to its role and content with respect to crustacean sexual determination and differentiation.