The distribution and proliferation among
Oryza species of miniature
Ping (
mPing), the only miniature inverted-repeat transposable element (MITE) that is active in all organisms, were investigated through analysis of 78 accessions encompassing nine of the 10 genomic constitutions of the genus
Oryza. The
mPing family transposons,
mPing,
Ping, and
Pong, were detected in only two of the AA genome species,
Oryza sativa and its direct ancestor
O. rufipogon, whereas the inactive rice MITE
Kiddo was detected in the AA, BB, CC, BBCC and CCDD genome species. Furthermore, the insertion sites and copy numbers of
mPing were considerably different among
O. rufipogon accessions. A phylogenetic analysis showed that the
O. rufipogon accessions used in this study could be grouped into four clusters which were not associated with the copy number of
mPing or the presence of
Ping. These results suggest that the
mPing family was present in the ancestor of
O. rufipogon and that
mPing proliferated independently in each accession. Based on these results, one possible evolutionary history of the distribution and proliferation of
mPing family in
O. rufipogon is discussed.
View full abstract