Genomic instability and mobile genetic elements in regions surrounding two discoidin I genes of Dictyostelium discoideum.

Abstract

We have found that the genomic regions surrounding the linked discoidin I genes of various Dictyostelium discoideum strains have undergone rapid changes. Wild-type strain NC-4 has three complete discoidin I genes; its axenic derivative strain Ax-3L has duplicated a region starting approximately 1 kilobase upstream from the two linked genes and extending for at least 8 kilobases past the genes. A separately maintained stock, strain Ax-3K, does not have this duplication but has undergone a different rearrangement approximately 3 kilobases farther upstream. We show that there are repeat elements in these rapidly changing regions. At least two of these elements, Tdd-2 and Tdd-3, have characteristics associated with mobile genetic elements. The Tdd-3 element is found in different locations in related strains and causes a 9- to 10-base-pair duplication of the target site DNA. The Tdd-2 and Tdd-3 elements do not cross-hybridize, but they share a 22-base-pair homology near one end. At two separate sites, the Tdd-3 element has transposed into the Tdd-2 element, directly adjacent to the 22-base-pair homology. The Tdd-3 element may use this 22-base-pair region as a preferential site of insertion.

• Authors: S J Poole, R A Firtel
• Journal: Molecular and cellular biology (Mol Cell Biol) Vol. 4 Issue 4 Pg. 671-80 (Apr 1984) ISSN: 0270-7306 [Print] United States
• PMID: 6325889 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• DNA Transposable Elements
• Discoidins
• Fungal Proteins
• Lectins
• Protozoan Proteins

Topics

• DNA Transposable Elements
• Dictyostelium (genetics)
• Discoidins
• Fungal Proteins (genetics)
• Gene Expression Regulation
• Genes
• Genes, Regulator
• Genetic Linkage
• Lectins
• Protozoan Proteins
• Repetitive Sequences, Nucleic Acid