Operon conservation and the evolution of trans-splicing in the phylum Nematoda

David B Guiliano, Mark L Blaxter

Research output: Contribution to journalArticlepeer-review


The nematode Caenorhabditis elegans is unique among model animals in that many of its genes are cotranscribed as polycistronic pre-mRNAs from operons. The mechanism by which these operonic transcripts are resolved into mature mRNAs includes trans-splicing to a family of SL2-like spliced leader exons. SL2-like spliced leaders are distinct from SL1, the major spliced leader in C. elegans and other nematode species. We surveyed five additional nematode species, representing three of the five major clades of the phylum Nematoda, for the presence of operons and the use of trans-spliced leaders in resolution of polycistronic pre-mRNAs. Conserved operons were found in Pristionchus pacificus, Nippostrongylus brasiliensis, Strongyloides ratti, Brugia malayi, and Ascaris suum. In nematodes closely related to the rhabditine C. elegans, a related family of SL2-like spliced leaders is used for operonic transcript resolution. However, in the tylenchine S. ratti operonic transcripts are resolved using a family of spliced leaders related to SL1. Non-operonic genes in S. ratti may also receive these SL1 variants. In the spirurine nematodes B. malayi and A. suum operonic transcripts are resolved using SL1. Mapping these phenotypes onto the robust molecular phylogeny for the Nematoda suggests that operons evolved before SL2-like spliced leaders, which are an evolutionary invention of the rhabditine lineage.
Original languageEnglish
Article numbere198
Pages (from-to)1871-1882
Number of pages12
JournalPLoS Genetics
Issue number11
Publication statusPublished - 2006


  • Animals
  • Base Pairing
  • Base Sequence
  • Biological Evolution
  • Conserved Sequence
  • Genes, Helminth
  • Molecular Sequence Data
  • Nematoda
  • Operon
  • Proteome
  • RNA Precursors
  • RNA, Messenger
  • RNA, Spliced Leader
  • Ribosomes
  • Trans-Splicing

Fingerprint Dive into the research topics of 'Operon conservation and the evolution of trans-splicing in the phylum Nematoda'. Together they form a unique fingerprint.

Cite this