Rice centromere 8 was previously proposed to be an "immature" centromere that recently arose from a genic region. Our comparative genomics analysis indicates that Cen8 was formed at its current location at least 7-9 million years ago and was physically shifted by a more recent inversion of a segment spanning centromeric and pericentromeric regions.
Ma, J., Wing, R. A., Bennetzen, J. L., & Jackson, S. A. (2007). Evolutionary history and positional shift of a rice centromere. Genetics, 177(2), 1217–1220. https://doi.org/10.1534/genetics.107.078709