CONCERN OF OTHERS

In 2015, a few years before the second generation of Oxitec’s Aedes aegypti mosquitoes was developed, a Yale researcher named Jeffrey Powell conducted a peer-reviewed study on the first version of Oxitec mosquitoes, the OX513A, which was released in Brazil that year. In the study, there was data that showed introgression, which is when one species transfers genes to another, between the natural population of mosquitoes and the GE mosquitoes, according to Powell. Gorman said that this introgression is true, but he said that only “wild” and natural genes are transferred to the wild population, not the transgenes, which are the genetically modified genes.

Powell said that this research was done using a genotyping tool that allowed the researchers to efficiently and quickly look at genes across the entire genome. The tool was used on both the target population and GE release strain. At first, the target population and GE release strain were genetically different, but when the researchers returned after the releases were done, they found genotypes in the natural population that weren’t there before.

This study was cited by the California Food and Safety Department (CFSD) and the environmental advocacy group Friends of the Earth, which urged more review before Oxitec could release GE mosquitoes in California due to fears that introgression into a more robust version of the mosquito offspring. Powell questioned whether the introgression could lead to hybridized, robust offspring, and is actually very common, Powell said. However, this question was not the main premise of the study, Powell said, and also related to the version of mosquitoes released during that time, which was a year before Oxitec released their second generation of mosquitoes. Gorman also said that the introgression is expected, but minimal.