A novel hAT element in Bombyx mori and Rhodnius prolixus: its relationship with miniature inverted repeat transposable elements (MITEs) and horizontal transfer

Abstract

Comparative analysis of transposable elements (TEs) from different species can make it possible to reconstruct their history over evolutionary time. In this study, we identified a novel hAT element in Bombyx mori and Rhodnius prolixus with characteristic GGGCGGCA repeats in its subterminal region. Meanwhile, phylogenetic analysis demonstrated that the elements in these two species might represent a separate cluster of the hAT superfamily. Strikingly, a previously identified miniature inverted repeat transposable element (MITE) shared high identity with this autonomous element across the entire length, supporting the hypothesis that MITEs are derived from the internal deletion of DNA transposons. Interestingly, identity of the consensus sequences of this novel hAT element between B. mori and R. prolixus, which diverged about 370 million years ago, was as high as 96.5% over their full length (about 3.6 kb) at the nucleotide level. The patchy distribution amongst species, coupled with overall lack of intense purifying selection acting on this element, suggest that this novel hAT element might have experienced horizontal transfer between the ancestors of B. mori and R. prolixus. Our results highlight that this novel hAT element could be used as a potential tool for germline transformation of R. prolixus to control the transmission of Trypanosoma cruzi, which causes Chagas disease.

The Origin and Evolution of Six Miniature Inverted-Repeat Transposable Elements in Bombyx mori and Rhodnius prolixus

“…This was consistent with previous studies in which the authors provided sufficient evidence supporting HTs of the transposons in the silkworm and the triatimine bug (Thomas et al 2010; Zhang et al 2013). …”

“…Previously, we identified a novel cluster of the hobo/Ac/Tam (hAT) superfamily in Bombyx mori and Rhodnius prolixus and found that this novel element generated MITEs in B. mori rather than in R. prolixus (Zhang et al 2013). It is likely that this element invaded into their hosts independently by HT (Zhang et al 2013).…”

“…It is likely that this element invaded into their hosts independently by HT (Zhang et al 2013). Here, we report the characterization and classification of six MITEs identified in both B. mori and R. prolixus .…”

BuT2 Is a Member of the Third Major Group of hAT Transposons and Is Involved in Horizontal Transfer Events in the Genus Drosophila

“…Two main groups, named Buster and Ac , were established by Arensburger et al (2011). Recently, Zhang et al (2013) described a novel hAT element horizontally transmitted between Bombyx mori ( hAT-4_BM ) and Rhodnius prolixus ( RP-hAT1 ), which might represent a third group well separated from the previous ones, Buster and Ac . In order to establish the relationships of BuT2 with the other members of the hAT superfamily, we built a phylogeny with the transposase amino acid sequences described previously (Arensburger et al 2011; Zhang et al 2013) along with other 14 homologous sequences (supplementary table S2, Supplementary Material online).…”

“…Recently, the hAT superfamily was divided into two major groups or families, Ac and Buster , based on the primary sequence of their transposases and by differences in target-site selection (Arensburger et al 2011). A small number of hAT transposons that do not fall into these two groups might comprise a third major group within the hAT superfamily (Arensburger et al 2011; Zhang et al 2013). …”