A Midwestern company’s quest to genetically engineer the world’s first hornless dairy cows hit a snag this summer when the U.S. Food and Drug Administration found extra genes in the cows that weren’t supposed to be there. The mistakes that FDA caught – but the company missed – highlight the importance of government oversight of gene-edited foods at a time when industry groups are pushing for deregulation.

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Latham, a biologist and former genetic engineer, also points to recent findings from Japan that he believes may be more consequential than the FDA’s findings, and have greater implications for the regulatory landscape. In a 2019 study, Japanese researchers reported that edited mouse genomes had acquired DNA from the E. coli genome, as well as goat and bovine DNA. This stray DNA came from the gene editing reagents, the delivery method used to make the edits.

The findings, Latham wrote in Independent Science News, “are very simple: cutting DNA inside cells, regardless of the precise type of gene editing, predisposes genomes to acquire unwanted DNA.” He said these findings “imply, at the very least, the need for strong measures to prevent contamination by stray DNA, along with thorough scrutiny of gene-edited cells and gene-edited organisms. And, as the Recombinetics case suggests, these are needs that developers themselves may not meet.”