An active piggyBac-like element in Macdunnoughia crassisigna

• Published in: Insect science 2008-12, Vol.15 (6), p.521-528
• Main Authors: Wu, Min, Sun, Zhi-Chan, Hu, Chun-Lin, Zhang, Gu-Feng, Han, Zhao-Jun
• Format: Article
• Language: English
• Subjects: Lepidoptera; Macdunnoughia crassisigna; piggyBac-like element (PLE); transposon
• ISSN: 1672-9609; 1744-7917
• DOI: 10.1111/j.1744-7917.2008.00241.x

In this paper, a highly conserved piggyBac‐like sequence, designated as McrPLE was cloned from a lepidopteran insect, Macdunnoughia crassisigna. It is 2 472 bp long in full length with a single open reading frame and encodes a 595 amino acid transposase. It shares identical terminal and sub‐terminal repeats with T. ni IFP2 and is flanked by the typical TTAA target‐site duplications. Alignment and phylogenetic analysis revealed that McrPLE had greater than 99.5% identity and appeared to be the closest one in phylogeny to IFP2 among the PLEs so far found in various species. Plasmid‐based excision and transposition assay proved it was mobile in cell culture. Otherwise, McrPLE element and all other highly conserved IFP2 sequences reported previously were found to share three common nucleotide substitutions. This suggests that the original IFP2 may be a related variant of a predecessor element that became widespread. The existence of nearly identical piggyBac sequence in reproductively isolated species was thought also a strong indication of horizontal transmission, which raises important considerations for the stability and practical use of piggyBac transformation vectors.