Amplification of repeated DNA sequences in wheat X rye hybrids regenerated from tissue culture.

Autor: Lapitan, N., Sears, R., Gill, B.
Zdroj: Theoretical & Applied Genetics; Mar1988, Vol. 75 Issue 3, p381-388, 8p
Abstrakt: Previous C-banding analysis of wheat ( Triticum aestivum)X rye ( Secale cereale) hybrids regenerated from tissue culture revealed enlarged C-bands in some rye chromosomes, but the molecular nature of the change was not determined. In situ hybridization using two DNA probes containing repeated sequences from rye telomeric heterochromatin was conducted on these wheatX rye hybrids and their progeny to investigate the occurrence of amplification in repeated sequences. Clones pSC 74 and pSC 119, which contain sequences from the 480-bp and 120-bp repeated DNA families of rye, respectively, were used as probes. Amplification of 480-bp repeated sequences in the short arm telomere of chromosome 7R was detected in three wheatxrye hybrids and their progeny. The amplified 480-bp sequences were detected by an enlarged hybridization site for pSC 74 at the 7RS telomere, and by the appearance at this same telomeric site of an unlabeled, blue chromosome segment in an otherwise completely brown chromosome hybridizing entirely to the biotin-labeled pSC 119 probe. This variant form of chromosome 7R was not observed in several 'Chaupon' plants, or in the other hybrids derived from the same embryos, indicating the origin of the change in tissue culture. The amplified sequences were inherited up to at least three generations. Deletions and translocations were also observed. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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