NSF Award
9630227
Burch MCB-96-3022 Eukaryotic genomes contain interspersed repetitive sequence elements that derive from the reverse flow of genetic information. These retrotransposons can be of two classes based upon whether they contain or lack long terminal repeat (LTR) sequences similar to those found in retroviruses. The chicken repeat 1 (CR1) elements are non-LTR retrotransposons and encodes its own reverse transcriptase. Sequence homology to elements found in fish, frogs, reptiles and, perhaps, mammals suggest that these elements are the prototype for a superfamily of non-LTR retrotransposons that exist in multiple vertebrate classes. Full-length elements for two distinct subfamilies of CR1 elements will be isolated and characterized. It will be determined if the CR1 reverse transcriptase is functional and avian and non-avian cell cultures will be assayed for CR1 retrotransposition events. %%% Retrotransposons are a major source of mutations in lower eukaryotes such as yeast and Drosophila and are implicated in several human genetic disorders. They also contribute to genome instability in other ways, for example, as targets for non-reciprocal homologous recombination events. This work will contribute to insight into the mechanisms and sequences required for the transposition of an evolutionary successful non-LTR element, CR1.
