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 order to stay under the ownership cap. In addition, networks may choose to sell off O&Os in smaller markets in order to concentrate on their stations in larger markets, or to give themselves leeway to purchase stations in other growing markets. The following are examples of transactions involving owned-and-operated stations in the United States: The DuMont network found itself in financial trouble in 1954, and decided to sell off its Pittsburgh owned-and-operated station, WDTV (channel 2), which was the only commercial VHF station in what was then a top ten television market in the United States. Westinghouse Electric Corporation bought