Within the 5′ flanking regions of two ripening-related genes from apple (Malus pumila), two short repeat sequences were identified and named Ars1 and Ars2 ( Apple repetitive sequences). Both elements were present in the promoter of the Md- ACS1-1 ACC synthase gene and Ars2 was also found in the promoter of a gene homologous to the ABG1 β-galactosidase gene. Database searches revealed other examples of each element in apple genomic sequences and a partial Ars2 element in a sequence from Asian pear (Pyrus pyrifolia). DNA dot blot analysis demonstrated that both elements are present in high numbers in the apple genome. Ars1 is thought to represent a MITE miniature inverted-repeat transposable element) related to the MITE Alien, while the identity of Ars2, though it is undoubtedly a transposable element, remains undetermined. DNA dot blot analysis and PCR amplification using primers designed from Ars1 and Ars2 showed that elements similar to Ars1 and Ars2 are present across the Rosaceae. The amplification patterns obtained using Ars1- and Ars2-specific primers with genomic DNA from different cultivars or mapping populations suggest that these elements could be used for fingerprinting and segregation analysis in Rosaceae. Evidence from DNA database searches suggests that they may be applicable to genetic studies in a wide range of other organisms. [ABSTRACT FROM AUTHOR]