title: Repeated horizontal transfers of four DNA transposons in invertebrates and bats.
abstract: BACKGROUND
  Horizontal transfer (HT) of transposable elements (TEs) into a new genome is considered as an important force to drive genome variation and biological innovation. However, most of the HT of DNA transposons previously described occurred between closely related species or insects.
  
  
  RESULTS
  In this study, we carried out a detailed analysis of four DNA transposons, which were found in the first sequenced twisted-wing parasite, Mengenilla moldrzyki. Through the homology-based strategy, these transposons were also identified in other insects, freshwater planarian, hydrozoans, and bats. The phylogenetic distribution of these transposons was discontinuous, and they showed extremely high sequence identities (>87%) over their entire length in spite of their hosts diverging more than 300 million years ago (Mya). Additionally, phylogenies and comparisons of transposons versus orthologous gene identities demonstrated that these transposons have transferred into their hosts by independent HTs.
  
  
  CONCLUSIONS
  Here, we provided the first documented example of HT of CACTA transposons, which have been so far extensively studied in plants. Our results demonstrated that bats had continuously acquired new DNA elements via HT. This implies that predation on a large quantity of insects might increase bat exposure to HT. In addition, parasite-host interaction might facilitate exchanging of their genetic materials.
authors.affiliation: School of Life Sciences, Chongqing University, Chongqing, 400044 China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Tang
authors.affiliation: College of Pharmacy and Life Science, Jiujiang University, Jiujiang, 332000 China.
authors.forename: Hua-Hao
authors.initials: HH
authors.lastname: Zhang
authors.affiliation: College of Forestry and Life Science, Chongqing University of Sciences and Arts, Yongchuan, Chongqing, 40216 China.
authors.forename: Ke
authors.initials: K
authors.lastname: Huang
authors.affiliation: College of Pharmacy and Life Science, Jiujiang University, Jiujiang, 332000 China.
authors.forename: Xiao-Gu
authors.initials: XG
authors.lastname: Zhang
authors.affiliation: School of Life Sciences, Chongqing University, Chongqing, 400044 China.
authors.forename: Min-Jin
authors.initials: MJ
authors.lastname: Han
authors.affiliation: School of Life Sciences, Chongqing University, Chongqing, 400044 China.
authors.forename: Ze
authors.initials: Z
authors.lastname: Zhang
keywords: CACTA transposons; Horizontal transfer; Mammals; Recent activity