Epigenetic regulation of transposable elements in the plant kingdom which allows for self-copying) within the coding of the transposon defines class I elements as autonomous or non-autonomous. Class I transposons can take the form of: Curiously, retrotransposons have been discovered to be the predominant form of transpositional element in plants with large genomes, such as maize and wheat, potentially indicating rapid success of this class of transposon in the creation of hybrids, such as wheat, peppermint and, in the distant past, maize. Plant hybridization often creates polyploids, with double, triple, quadruple or more the number of chromosomes present in the parent generation. Polyploid hybrids seem to be particularly susceptible
Owned-and-operated television stations in the United States is now held by WNLO and the channel 17 frequency is now held by WBXZ-LP; WNED still holds the virtual channel 17 in the Buffalo market, but has not advertised it since the early 2000s). Similarly, CBS bought UHF stations WGTH-TV (channel 18) in Hartford and WOKY-TV (channel 19, later on channel 18) in Milwaukee in 1955, and changed their call letters to WHCT-TV and WXIX-TV, respectively. However, CBS' ratings were astonishingly low in those markets. In 1959, CBS decided to move its Hartford and Milwaukee affiliations to VHF stations WTIC-TV and WITI-TV (channel 6) respectively, and sold off what