A 52-week safety study in cynomolgus macaques for genetically modified rice expressing CrylAb/lAc protein

A 52-week feeding study in cynomolgus macaques was carried out to evaluate the safety of Bt rice Huahui 1 (HH1), a transgenic rice line expressing CrylAb/lAc protein. Monkeys were fed a diet with 20% or 60% HH1 rice, 20% or 60% parental rice (Minghui 63, MH63), normal diet, normal diet spiked with purified recombinant Cry1Ab/1Ac fusion protein or bovine serum albumin (BSA) respectively. During the feeding trail, clinical observations were conducted daily, and multiple parameters, including body weight, body temperature, electrocardiogram, hematology, blood biochemistry, serum metabolome and gut microbiome were examined at regular intervals. Upon sacrifice, the organs were weighted, and the macroscopic, microscopic and electron microscopic examinations were performed. The results show no adverse or toxic effects of Bt rice HUH or Cry1Ab/lAc fusion protein on monkeys. Therefore, the present 52 -week primate feeding study suggests that the transgenic rice containing Cry 1Ab/lAc is equivalent to its parental rice line MH63. (C) 2016 Elsevier Ltd. All rights reserved.