Worm Breeder's Gazette 9(2): 33
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
A restriction fragment polymorphism between two strains of C. elegans (Bristol and Bergerac) has been found to be due to the insertion into the Bergerac strain of an approximately 1.8 kb DNA segment. The inserted DNA has an inverted repeat structure with no separating loop and is visible upon electron microscopic analysis as a .85 kb double stranded foldback. We have named this inserted DNA FB1. FB1 defines a repetitive family of approximately 20 additional members visualized by Southern blotting, and about 10 to 20% of the sites vary between strains. The foldback does not cross hybridize with TC1, and a preliminary restriction map is not similar to that of TC1. We have observed that the 1.8 kb foldback structure has symmetrically located Hinfl and AluI restriction sites near each end of the element. HinfI cuts nearly at the ends of the element, releasing a single internal fragment of 1.77 kb, while AluI cuts 350 bp internal to the foldback releasing a single 1.1 kb internal fragment. We are currently sequencing several members of this polymorphic foldback family as well as the empty site from Bristol filled by FB1 in Bergerac. We hope to determine if this family of foldback elements transposes in C. elegans and if it is similar to known foldback transposable elements from other species. Please let us know about any non-TC1 insertions of approximately 1.8 kb that we can probe for FB1. A restriction digest of a potential FB1 insertion should yield a 1.7 to 1.8 kb Hinfl fragment, and/or a 1.1 kb AluI fragment.