Genetic techniques are capable of finding the entire sequence (“genome”) of DNA letters (“base pairs”), and have recently been applied to completely sequence 61 unrelated rainbow trout and steelhead individuals. The study found that one in every 64 letters varied across the rainbow trout examined (with variability in more than 30 million locations), and that there were more than 4 million locations where the individual DNA letters differ substantially. These places of variability are known as single nucleotide polymorphisms (SNPs) to can be used to allocate individual fish to their birth populations, identify genetic variation underlying fitness traits, and characterize genes. The vast new SNP database will be a key resource for future genetic analyses, and was authored by a collaboration between US and Norwegian scientists including SAFS professor Kerry Naish. The paper was published in Frontiers in Genetics.