Rte-1, a retrotransposon-like element in Caenorhabditis elegans

We have characterized a retrotransposon-like element (Rte-1) in C. elegans. It was identified while we were sequencing the pim related kinase-1 (prk-1) gene. The element is 3,298 bp long and flanked by a 200 bp direct repeat. 95 bp of the direct repeat are present in the coding region of prk-1. Rte-1 contains an open reading frame, in the opposite orientation of prk-1, potentially encoding 625 amino acids, with similarity to reverse transcriptases. The element is most similar to members of the non-LTR group of retrotransposable elements. There is weak homology of the predicted amino acid sequence of Rte-1 to several reverse transcriptase-like genes identified by the C. elegans genome sequencing consortium, suggesting that there may be a large family of these elements. Southern blots indicate that there are approximately 10-15 additional Rte-1 elements in the C. elegans Bristol N2 genome and a similar number is found in the genomes of two other geographically distinct strains. The insertion pattern of Rte-1 is polymorphic between these strains.