Researchers from the University of North Carolina-Chapel Hill and the Pacific Northwest National Laboratory characterize a pathogenic coronavirus behind a swine acute diarrhea syndrome (SADS) in pigs. The team came up with a recombinant version of SADS-CoV that had a red fluorescent reporter-coding gene replacing one of the virus' open reading frames, generating complementary DNAs that covered much of the SADS-CoV genome in the process.