Molecular characterization of  a mariner-like element in the Atta sexdens rubropilosa genome.
Mobile  elements are widely present in eukaryotic genomes. They are repeated DNA  segments that are able to move from one locus to another within the genome.  They are divided into two main categories, depending on their mechanism of  transposition, involving RNA (class I) or DNA (class II) molecules. The mariner-like  elements are class II transposons. They encode their own transposase, which is  necessary and sufficient for transposition in the absence of host factors. They  are flanked by a short inverted terminal repeat and a TA dinucleotide target  site, which is duplicated upon insertion. The transposase consists of two domains,  an N-terminal inverted terminal repeat binding domain and a C-terminal  catalytic domain. We identified a transposable element with molecular  characteristics of a mariner-like element in Atta sexdens rubropilosa genome. Identification started from a PCR with degenerate primers and queen  genomic DNA templates, with which it was possible to amplify a fragment with mariner transposable-element homology. Phylogenetic analysis demonstrated that this  element belongs to the mauritiana subfamily of mariner-like  elements and it was named Asmar1. We found that Asmar1 is  homologous to a transposon described from another ant, Messor bouvieri.  The predicted transposase sequence demonstrated that Asmar1 has a  truncated transposase ORF. This study is part of a molecular characterization  of mobile elements in the Atta spp genome. Our finding of mariner-like  elements in all castes of this ant could be useful to help understand the  dynamics of mariner-like element distribution in the Hymenoptera.
Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brasil. paularez@usp.br
P
P
Rezende-Teixeira
J B
JB
do Amaral
F
F
Siviero
G M
GM
Machado-Santelli
D000818:Animals; D001000:Ants / Q000145:classification / Q000235:genetics; D004251:DNA Transposable Elements / Q000235:genetics; D016678:Genome / Q000235:genetics*; D010802:Phylogeny
D004251:DNA Transposable Elements