Nuclear mitochondrial pseudogenes (numts) are non-functional copies of mtDNA in the nuclear genome, which have been found in major clades of eukaryotic organisms. Among insects, Orthoptera, especially grasshoppers, are known to have exceptionally high numbers of numts, making them an ideal model system for studying numts. I have shown that numts can be easily coamplified with mtDNA using PCR-based methods, that numt coamplification can compromise the effectiveness of DNA barcoding and mitochondrial systematics, that numts are extremely abundant across major lineages of Orthoptera, and that numts can be effectively used as molecular fossils in recently diverged lineages. This line of research stemmed from my own struggle with generating mitochondrial sequences from grasshoppers, which has serendipitously transformed into an exciting area of research. There are still numerous questions to be addressed because the molecular mechanisms driving the nuclear integration of mtDNA, and maintenance and transmission of numts are still largely unknown. This line of research fits well within the field of molecular systematics and I find it fascinating in terms of molecular evolution. I intend to continue and expand this research program in the future.

Representative Papers:

  • Song, H., Moulton, M.J. and Whiting, M.F. 2014. Rampant nuclear insertion of mtDNA across diverse lineages within Orthoptera (Insecta) PLoS ONE 9(10): e110508. doi:10.1371/journal.pone.0110508
  • Song, H., Moulton, M.J.*, Hiatt, K.D.* and Whiting, M.F. 2013. Uncovering historical signature of mitochondrial DNA hidden in the nuclear genome: the biogeography of Schistocerca revisited. Cladistics 29(6):643-662
  • Song, H., Buhay, J.E., Whiting. M.F., and Crandall, K.A. 2008. Many species in one: DNA barcoding overestimates the number of species when nuclear mitochondrial pseudogenes are coamplified. Proceedings of the National Academy of Sciences of the U.S.A. 105(36): 13486-13491.