Chromosomal rearrangements caused by the aberrant transposition of double Ds elements are formed by Ds and adjacent non-Ds sequences.
The Ds-induced unstable sh-m6258 allele is caused by the insertion of at least 45 kb of non-sh DNA. Genomic clones spanning the two junctions of sh sequences with insert sequences were isolated and analysed. The long insert in the sh-m6258 allele is bordered by Ds sequences on either side. A 3 kb double Ds structure which consists of one complete Ds element of approximately 2 kb and one half Ds element of approximately 1 kb was found in the sh-m6258 allele at the junction between the 3' region of the sh locus and the insert. At the junction between the 5' region of the sh locus and the insert a half Ds element is present. This truncated Ds element was probably left behind after the excision of a 2 kb Ds element from a 3 kb double Ds structure similar to that found at the 3' junction. Sequence analysis of the insert sequences beyond the Ds elements demonstrated that the long inserts in both the sh-m6258 and the sh-m5933 alleles originated from the same contiguous chromosomal segment in their common progenitor strain. One revertant derivative of the sh-m6258 allele was investigated. In the revertant strain, which displays a normal non-shrunken phenotype, a 2 kb Ds element is present at the site of the 45 kb insert in the mutant allele. This 2 kb insertion, which is located in the last but one intervening sequence of the Sh gene, does not inhibit expression of the gene.(ABSTRACT TRUNCATED AT 250 WORDS)
Döring
H P
HP
Institut für Genetik, Universität zu Köln, Federal Republic of Germany.
Pahl
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I
Durany
M
M
D000483:Alleles; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D008969:Molecular Sequence Data; D011995:Recombination, Genetic; D015183:Restriction Mapping; D003313:Zea mays / Q000235:genetics*
D004251:DNA Transposable Elements