Majin:: A miniature DNA element associated with the genomes of pome fruit trees

Sequencing of the sequence tagged site-DNA marker fragments linked to the fruit skin-color gene in apple revealed two fragments containing insertions that are associated with yellow skin color, and are alleles of the red skin gene (Rf). One fragment resulted from the insertion of a 76-bp inverted repeat, whereas the 163 bp in the other fragment was characterized as a mobile element because of the presence of target site duplication. A database search found this latter element in the 5' flanking regions or intron of six apple genes. DNA blot analysis revealed that the element is highly reiterated, with a copy number of between 5000-6000 in the genome of Maloideae (pome) fruit trees. We named this element Majin. Inter-transposon amplified polymorphism using primers from this element resulted in polymorphic bands among apple cultivars.