Operons are a conserved feature of nematode genomes.
Bottom Line: The organization of genes into operons, clusters of genes that are co-transcribed to produce polycistronic pre-mRNAs, is a trait found in a wide range of eukaryotic groups, including multiple animal phyla.We have nevertheless identified putative operons conserved between Enoplea and Chromadorea.Our data suggest that operons and "spliced leader" (SL) trans-splicing predate the radiation of the nematode phylum, an inference which is supported by the phylogenetic profile of proteins known to be involved in nematode SL trans-splicing.
Affiliation: School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom email@example.com.Show MeSH
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Mentions: We were able to identify credible homologs of sna-2 in the genomes of all nematodes in which searches were carried out, including T. spiralis and R. culicovorax, indicating that this gene encodes a nematode-wide SL trans-splicing component (Figure S2). Searches of the same datasets identified clear sna-1 and sut-1 orthologs in the chromadorean nematodes (Figure 5), extending the previously reported phylogenetic distribution of sut-1 (MacMorris et al. 2007). In contrast, the only enoplean genome in which we were able to identify a sut-1 homolog was R. culicivorax (Figure 5). We could not detect sna-1 homologs in any of the enoplean genomes that we assayed. These data suggest that the gene duplication event that gave rise to sna-1 and sut-1 occurred after the separation of the two major nematode taxa; however, we cannot rule out that the possibility that our failure to detect sna-1 homologs is due to the incomplete state of the enoplean genome drafts.
Affiliation: School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, United Kingdom firstname.lastname@example.org.