Geneticists at Texas A&M University College of Veterinary Medicine have conducted DNA testing on more than 40,000 bison from public and private bison herds. They have developed two genetic assays to uncover past evidence of hybridization between bison and domestic cattle. The first genetic test involves mitochondrial DNA (mtDNA) which is only passed from mother to offspring. You might remember from biology class that the mitochondria is referred to as the powerhouse of the cell because it is critical for energy conversion.