Transduplication resulted in the incorporation of two protein-coding sequences into the Turmoil-1 transposable element of C. elegans

TL;DR

This study reveals that the Turmoil-1 transposable element in C. elegans has incorporated two protein-coding sequences through transduplication, a process previously known mainly in plants, highlighting a novel aspect of animal genome evolution.

Contribution

It demonstrates for the first time that transduplication of protein-coding genes occurs in an animal, specifically within the Turmoil-1 transposable element in C. elegans.

Findings

Turmoil-1 contains a conserved RRM motif from rsp-2 gene

Incorporation of cpg-3 gene fragment into Turmoil-1

Potential creation of a new open reading frame in C. elegans

Abstract

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-1 transposable element in C. elegans has incorporated two protein-coding sequences into its inverted terminal repeat (ITR) sequences. The ITRs of Turmoil-1 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-1 insertion. Mutations at the 5' splice site of this open reading frame may have reactivated the transduplicated RRM motif