title: MudrA-like sequences from rice and sugarcane cluster as two bona fide transposon clades and two domesticated transposases.
abstract: The Mutator system of maize has been described as the most active and mutagenic plant transposon. The autonomous element MuDR contains two genes: mudrA encoding the transposase and mudrB whose product function remains undetermined. MudrA-like coding domain showed to be the most abundantly expressed transposon-related sequence in sugarcane transcriptome. A previous report identified the existence of at least four clades of mudrA-like sequences in sugarcane, rice and arabidopsis, which already existed prior to the Monocot-Eudicot split. To gain understanding about the abundance, distribution, copy number and diversity of mudrA-like sequences, a comparative study between sugarcane and rice was performed. As a result, it was possible to identify that copy number greatly differs and, at least in grasses, there was a class-specific amplification with a burst of Class II elements. Structural analyses performed on rice genomic sequences revealed that while Class I and Class II clades comprise elements with transposon features, Class III and Class IV no longer possess TIRs and correspond to domesticated transposases.
authors.affiliation: Departamento de Botânica, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo, 05508-090 SP, Brazil. nilosaccaro@yahoo.com.br
authors.forename: Nilo Luiz
authors.initials: NL
authors.lastname: Saccaro
authors.forename: Marie-Anne
authors.initials: MA
authors.lastname: Van Sluys
authors.forename: Alessandro
authors.initials: A
authors.lastname: de Mello Varani
authors.forename: Magdalena
authors.initials: M
authors.lastname: Rossi
mesh_terms: D000595:Amino Acid Sequence; D002874:Chromosome Mapping; D032461:Chromosomes, Plant; D017124:Conserved Sequence; D004251:DNA Transposable Elements; D018628:Gene Dosage; D017343:Genes, Plant; D012275:Oryza / Q000235:genetics*; D010802:Phylogeny; D031786:Saccharum / Q000235:genetics*; D019895:Transposases / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D019895:Transposases