MOLECULAR EVOLUTION OF MAGELLAN, A MAIZE TY3 GYPSY-LIKE RETROTRANSPOSON/

The magellan transposable element is responsible for a spontaneous 5.7 -kb insertion in the maize wx-M allele. This element has the sequence and structural characteristics of a Ty3/gypsy-like retrotransposon. Th e magellan element is present in all Zea species and Tripsacum anderso nii; it is absent, however, in the genomes of all other Tripsacum spec ies analyzed. The genetic distances between magellan elements suggest that this retrotransposon is evolving faster than other Zea nuclear lo ci. The phylogeny of magellan within Zea and T. andersonii also reveal s a pattern of interspecies transfers, resulting in the movement of ma gellan subfamilies between different species genomes. Interspecific hy bridization may be a major mechanism by which this retrotransposon inv ades and establishes itself in new taxa.