There are 9 genes that are essential for the formation and function of modern magnetosomes: mamA, mamB, mamE, mamI, mamK, mamM, mamO, mamP, and mamQ.[23] In addition to these 9 genes that are well conserved across all MTB, there are more than 30 total genes that contribute to magnetotaxis in MTB.[23] These non-essential genes account for the variation in magnetite/greigite crystal size and shape, as well as the specific alignment of magnetosomes in the cell.