Identification and molecular characterisation of mariner-like elements in the tomato leaf miner Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae).
The tomato leafminer, Tuta absoluta (Meyrick), (Lepidoptera: Gelechiidae), is a devastating pest of tomato that has recently become a major threat to tomato production in many countries in the Mediterranean Basin, Africa and Asia. Mariner-like elements (MLEs) are class-II transposons with short inverted terminal repeats (ITR) flanking a single open reading frame (ORF) coding for a transposase. In the present study, we have isolated eight full-length MLEs from the tomato leaf miner by PCR amplification, using a single primer designed from the ITR of Hyalophora cecropia L. Mariner signature sequence D, D(34)D, as well as the conserved amino acid motifs, WVPHEL and YSPDLAP(T)D, were identified. However, sequences analysis revealed defective elements with the presence of several kinds of mutations generating stop codons, frameshifts, and non-functional transposase. Based on predicted transposase sequences, T. absoluta MLEs (Tamar1) belongs to the cecropia subfamily and clustered closely with MLEs from other Lepidoptera members suggesting vertical genetic transmission from a common ancestor. The identification of mariner-like elements in this invasive species will be useful to understand the genome dynamics in Lepidoptera.