The Tpv2 family of retrotransposons of Phaseolus vulgaris: structure, integration characteristics, and use for genotype classification

The Tpv2 family of transposable elements of common bean, Phaseolus vulgaris , belongs to the Tyl/copia group of long terminal repeat (LTR) containing r etrotransposons. By reverse transcriptase (RT)-PCR and by analysis of genom ic clones, we characterized four of the approximately 40 copies present in the Phaseolus genome, and the genomic environment of their integration site s. Tpv2 integrated preferentially into actively transcribed regions. While none of the isolated elements had all the functional domains necessary for transposition, analysis of bean cultivars suggested that some members of th e Tpv2 family transposed in recent breeding history. Probes derived from Tp v2, as well as flanking genomic sequences, may be useful for classifying Ph aseolus cultivars.