PSL - A NOVEL SPM-LIKE TRANSPOSABLE ELEMENT FROM PETUNIA-HYBRIDA

The identification of a spontaneous mutable Hf1 allele in Petunia hybr ida provided an opportunity to isolate and characterize a novel transp osable element. This 9.9 kb element has features in common with member s of the Spm family, such as homologous terminal inverted repeats and a 3 bp target site direct duplication within the Hf1 gene. The element is named Petunia Spm-like (Psl). The footprints left by excising elem ents have been isolated from several germinal revertants and sequence analysis shows similarities to those left by other Spm family members. Southern analysis shows that the transposon is present at low copy nu mber in the genome of different inbred lines and species of Petunia. T he germinal excision frequency of Psl was 21-33% in outcross populatio ns. The element appears to be very mobile somatically in the inbred li ne V26, with 38% of plants from an inbred population showing new Psl-h ybridizing bands by Southern analysis. The high somatic and germinal e xcision frequency demonstrated by Psl suggests that this element may h ave utility for gene tagging in petunia.