Transduplication resulted in the incorporation of two protein-coding sequences into the Turmoil-I transposable element of C. elegans

Transposable elements may acquire unrelated gene fragments into their sequences in a process called transduplication. Transduplication of protein-coding genes is common in plants, but is unknown of in animals. Here, we report that the Turmoil-I transposable element in C. elegans has incorporated two protein-coding sequences into its inverted terminal repeat (ITR) sequences. The ITRs of Turmoil-I contain a conserved RNA recognition motif (RRM) that originated from the rsp-2 gene and a fragment from the protein-coding region of the cpg-3 gene. We further report that an open reading frame specific to C. elegans may have been created as a result of a Turmoil-I insertion. Mutations at the 5' splice site of this open reading frame may have reactivated the transduplicated RRM motif.