Effects of genetically modified rice expressing Cry1C protein on zebrafish after a 90-day dietary intake

Fish is an excellent model animal with which to assess the potential effects of exogenous toxins. In fields of transgenic Bacillus thuringiensis (Bt) rice, fish would be exposed to Bt protein released from Bt rice into the water environment or by way of direct feeding on deposited plant material. Whether Bt rice pose potential risks to the growth and health of fish have gradually become a focus of attention for environmentalists and the fish farming industry. In the present study, we assessed transgenic cry1C rice (T1C-19) on the growth and development of a fish species by feeding 45-days post-fertilization (dpf) zebrafish a diet with 20% T1C-19 rice, 20% parental rice (Minghui 63, MH63), or no rice (as a control) for 90 days. Although the zebrafish were directly exposed to Cry1C protein at a level of 137.28 ± 17.65 ng/g feed by feeding on diet containing the T1C-19 rice, no significant differences were found in the general health such as survival rate, body length and body weight, condition factor (CF), specific growth rate (SGR), and intestinal digestive and liver antioxidant enzyme activities (Trypsin, Maltase, SOD and CAT), as well as in the intestinal microbial diversity among the three test groups. Our results indicate that the development of zebrafish was not adversely affected by dietary intake of Cry1C protein which will provide an experimental basis for the aquaculture feed industry to employ transgenic rice T1C-19 for commercial purpose.