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 network chose to affiliate with Westinghouse's KYW-TV, Philadelphia's longtime NBC affiliate. After a bidding war, WCAU was sold to NBC. KYW became a CBS owned-and-operated station after Westinghouse's merger with CBS a few months later. As part of the same deal, NBC in turn transferred its own O&O stations in Denver (KCNC-TV, channel 4) and Salt Lake City (KUTV) to Westinghouse/CBS, and those stations became CBS O&Os after Westinghouse merged with CBS. NBC and CBS also swapped transmitting facilities in Miami between the then-weaker CBS-owned WCIX (channel 6, now WFOR-TV, channel 4) and the then-stronger NBC-owned WTVJ (channel 4, now