Variation in genome size of argasid and ixodid ticks

Insect Biochem Mol Biol. 2007 May;37(5):399-408. doi: 10.1016/j.ibmb.2006.12.007. Epub 2007 Jan 17.


The suborder Ixodida includes many tick species of medical and veterinary importance, but little is known about the genomic characteristics of these ticks. We report the first study to determine genome size in two species of Argasidae (soft ticks) and seven species of Ixodidae (hard ticks) using flow cytometry analysis of fluorescent stained nuclei. Our results indicate a large haploid genome size (1C>1000 Mbp) for all Ixodida with a mean of 1281 Mbp (1.31+/-0.07 pg) for the Argasidae and 2671 Mbp (2.73+/-0.04 pg) for the Ixodidae. The haploid genome size of Ixodes scapularis was determined to be 2262 Mbp. We observed inter- and intra-familial variation in genome size as well as variation between strains of the same species. We explore the implications of these results for tick genome evolution and tick genomics research.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Argasidae / classification
  • Argasidae / genetics*
  • Evolution, Molecular
  • Female
  • Flow Cytometry
  • Genetic Variation*
  • Genome, Insect*
  • Ixodidae / classification
  • Ixodidae / genetics*
  • Male
  • Phylogeny
  • Sex Factors